Journal of Threatened Taxa | www.threatenedtaxa.org | 26 August 2022 | 14(8): 21588–21604

 

ISSN 0974-7907 (Online) | ISSN 0974-7893 (Print) 

https://doi.org/10.11609/jott.7842.14.8.21588-21604

#7842 | Received 24 January 2022 | Final received 26 April 2022 | Finally accepted 31 July 2022

 

 

 

An overview of the fish diversity and their threats in the Gowthami-Godavari Estuary in Andhra Pradesh, India

 

Paromita Ray 1, Giridhar Malla 2, J.A. Johnson 3  & K. Sivakumar 4

 

1–3 Wildlife Institute of India, Chandrabani, Dehradun, Uttarakhand 248001, India.

4 Present address: Department of Ecology and Environmental Sciences, Pondicherry University, Pondicherry 605014, India.

1 paromitaray20@gmail.com, 2 mallagiridhar@gmail.com, 3 jaj@wii.gov.in, 4 ksivakumarwii@gmail.com (corresponding author)

 

 

Editor: Rajeev Raghavan, Kerala University of Fisheries and Ocean Studies, Kochi, India.          Date of publication: 26 August 2022 (online & print)

 

Citation: Ray, P., G. Malla, J.A. Johnson & K. Sivakumar (2022). An overview of the fish diversity and their threats in the Gowthami-Godavari Estuary in Andhra Pradesh, India. Journal of Threatened Taxa 14(8): 21588–21604. https://doi.org/10.11609/jott.7842.14.8.21588-21604

 

Copyright: © Ray et al. 2022. Creative Commons Attribution 4.0 International License.  JoTT allows unrestricted use, reproduction, and distribution of this article in any medium by providing adequate credit to the author(s) and the source of publication.

 

Funding: United Nations Development Fund (UNDP), Global Environment Facility (GEF), Ministry of Environment, Forests and Climate Change (MoEF&CC), Andhra Pradesh Forest Department (APFD).  This study was part of a UNDP-GEF-MoEF&CC-APFD project, ‘Establishment of Knowledge-based Management System in the East Godavari River Estuarine Ecosystem (EGREE Project)’ of the Wildlife Institute of India. The authors would also like to acknowledge the support of the Andhra Pradesh Forest Department, who provided us with the necessary permissions (Rc. No. 23833/2012/WL-S dated 29/11/2013)

 

Competing interests: The authors declare no competing interests.

 

Author details: Paromita Ray is an independent researcher, working on freshwater fish ecology and conservation in Andhra Pradesh.  Giridhar Malla is an independent researcher, working on small cat conservation in India. He also works towards the conservation of freshwater and coastal habitats in Andhra Pradesh.

Dr. J.A. Johnson is a Scientist at the Wildlife Institute of India, with an expertise in freshwater fish ecology and taxonomy.  Dr. K. Sivakumar is a former Scientist at the Wildlife Institute of India and presently working as Professor at Pondicherry University, with an expertise in conservation of freshwater and marine ecosystems.

 

Author contributions: PR—collection of field data, analysis, preparation of manuscript. GM—collection of field data and preparation of manuscript. JAJ—guidance on the study, manuscript reviewing and editing. KS—guidance on the study, manuscript editing and reviewing,

 

Acknowledgements: This study was part of a UNDP-GEF-MoEF&CC-APFD project, ‘Establishment of Knowledge-based Management System in the East Godavari River Estuarine Ecosystem (EGREE Project)’ of the Wildlife Institute of India. The authors would like to thank the director, and dean of the Wildlife Institute of India for providing their support in terms of infrastructure and guidance. The authors would also like to acknowledge the support of the Andhra Pradesh Forest Department, who provided us with the necessary permissions (Rc. No. 23833/2012/WL-S dated 29/11/2013) and support to carry out the study between 2013 and 2017. We are very grateful to Prasad Anna, Raju, and other local fishers of the East Godavari district, without whom this project would not have been possible. We thank Leela Prasad for helping us during some of the field surveys and Steve Lockett for his assistance in editing this manuscript.

 

 

 

Abstract: The fish diversity of different estuarine habitats of the Gowthami-Godavari River was studied from 2014 to 2017. We recorded 231 species of finfishes belonging to 27 orders, 81 families, and 167 genera. Perciformes was the most speciose order, followed by Carangiformes and Clupeiformes. Of the 231 species, one is an Endangered species (Silonia childreni), three are Vulnerable (Tenualosa toli, Cirrhinus cirrhosis, and Wallago attu), three are Near Threatened, and 11 are Data Deficient species. We also recorded five exotic species from the study area, of which Oreochromis mossambicus was the most dominant. The major threats, including potential impacts of river regulation and climate change on the estuarine habitats of Gowthami-Godavari, are also discussed. 

 

Keywords: Coringa, dam, eastern coast, ichthyofauna, mangroves. 

 

 

INTRODUCTION

 

Among the large monsoonal rivers of the Indian peninsula, the Godavari River is the largest, with a drainage basin of 312,812 km2 (Rao et al. 2015). The river originates at Triambakeshwar in the Western Ghats and travels eastward for ~1,460 km flowing through eight states and various landscapes such as the Western Ghats, Deccan traps of central India, and the Eastern Ghats along the eastern coast. It finally drains into the Bay of Bengal through a number of distributaries before creating a large, fertile delta in Andhra Pradesh. The Godavari river basin accounts for nearly 10% of India’s geographical area, thereby playing a major role in accruing socio-ecological, economic, and cultural benefits to the country.

At its confluence with Bay of Bengal, numerous distributaries of the Godavari River form an estuarine complex constituting a diverse array of coastal habitats that include the estuaries formed at the river mouths, mangrove forests, and a large bay partially enclosed by a natural sand spit known as Hope Island. The mangroves created at the confluence of Gowthami River, a major distributary of the Godavari River, are among the largest mangrove forests in India. These habitats support rich and unique biodiversity, including rare mangrove species such as Ceriops decandra and Xylocarpus granatum, and threatened mammals such as the Fishing Cat Prionailurus viverrinus and Smooth-coated Otter Lutrogale perspicillata (Malla 2014; Malla et al. 2019). The estuarine complex and the mangrove-lined creeks of the estuary located at the interface of freshwater and salt water also contributes immensely to the region’s fisheries particularly supporting the sustenance of the local small-scale fisheries. 

Many studies, including those by Krishnamurthy & Jeyaseelan (1981), Mukherjee et al. (2013), Ramachandra et al. (2013), and Ramanujam et al. (2014), have documented the diversity of fish fauna present in Indian estuaries. In the case of the lower basin of the Godavari River, earlier ichthyological studies provide substantial information on the distribution and taxonomy of fish species (Day 1888; Chacko & Ganapati 1949; Rao 1965, 1976; Rajyalakshmi 1973; Rao 1976; Talwar & Jhingran 1991). Species including Awaous fluviatilis Rao, 1971 and Incara multisquamatus Rao, 1961 were first described from the Godavari delta. Nearly two decades ago, Krishnan & Mishra (2001) provided a comprehensive summary of the fish diversity of the Godavari River estuary, accounting for 312 species belonging to 189 genera and 88 families.

In this paper, we provide an overview of the fish diversity and distribution in different habitats of the Godavari River estuarine complex, and specifically focusing on the fish diversity in the mangrove-lined creeks. We also discuss various threats to these mangrove forests, and their fish communities. This study is important in the context of the vulnerability of this estuary, and its biological communities to potential large-scale changes triggered by rising sea levels and freshwater regulation by an under-construction large dam.  

 

 

METHODS

 

Study area

This study was conducted in the Godavari River Estuary located in the southeastern state of Andhra Pradesh in peninsular India. Before its confluence with the sea, the river branches out into two major distributaries, namely the Gowthami-Godavari and Vasistha-Godavari. The present study focuses on the Gowthami distributary of the river (16.98 °N, 82.30 °E and 16.58 °N, 82.31 °E).

With an area of 316 km2, a substantial part of the mangroves formed at the northern confluence of Gowthami-Godavari with the sea are protected inside the Coringa Wildlife Sanctuary (CWS) (Bagaria et al. 2021). Here, the mangroves are drained by three major sub-tidal creeks, namely Thulyabhaga, Coringa, and Gaderu; these creeks flow south to north, dividing the sanctuary into different zones. Another smaller sub-tidal creek, namely Giriyampeta is located outside the southern border of the sanctuary. In addition to these major creeks, the sanctuary is drained by several smaller sub-tidal and intertidal creeks.

The subtidal creeks drain into the Kakinada Bay, a naturally formed semi-enclosed bay formed at the northern edge of the sanctuary. The main branch of the Gowthami-Godavari creates a riverine estuary at the southern edge of the sanctuary, where the tidal influence can extend up to 50 km upstream.

 

Sampling sites

Fish sampling was carried out across 52 sites between 2014 and 2017 (Figure 1). Of these, 28 sites were located within mangrove creeks of the CWS (Image 1), 16 sites were in the riverine part of the estuary, and eight sites were located in the Kakinada Bay. Additional surveys were carried out in the local fish markets and landing centers located adjacent to the mangroves, and the river mouth.

In the main river within the sanctuary, fishes were collected using locally available trammel nets and gill nets, which were set perpendicular to the water flow for a period of one hour during low tides. In the case of intertidal creeks, block nets were placed at the creek entrance at the beginning of low tide. The fishes that remained within the blocked creek were collected before the onset of the next high tide. Since sampling was conducted inside a protected area, only unidentified specimens were collected for further identification in the laboratory. On a few occasions, specimens were collected opportunistically from fishers’ catches from the subtidal creeks, bay, or the river mouth.

Identifications were made using the FAO Fish Catalogue (Fischer & Whitehead 1974; Fischer & Bianchi 1984) and other taxonomic keys available for the region (Day 1888; Jayaram 2010). The correct taxonomy of the species was updated in accordance with the California Academy of Sciences’ online repository, the Catalog of Fishes (Fricke et al. 2021). The functional guilds and migratory behavior of the species were confirmed following FishBase (Froese & Pauly 2021) while the threatened status of each of the species followed the latest IUCN Red List of Threatened Species (IUCN 2021).

 

 

RESULTS AND DISCUSSION

 

Diversity and distribution of fishes in the estuary

In the present study, total of 231 species of finfish belonging to 27 orders, 81 families, and 167 genera were recorded (Table 1; Images 4–7). Order Perciformes was the most speciose with 41 species, 22 genera, and 10 families. It was followed by Carangiformes (30 species, 29 genera, and 12 families), and Clupeiformes (25 species, 16 genera, and five families). Among the families (Figure 2), Carangidae was represented by the highest number of species (16 species), followed by Gobiidae and Sciaenidae (both represented by 12 species each). Of all the recorded species, 179 were carnivorous, 45 were omnivorous and two were herbivorous.

In comparison to the earlier study carried out by Krishnan & Mishra (2001), fewer finfish species were recorded during this study. This difference may not necessarily suggest a decline in the overall number of species in the estuary, but is more reflective of the taxonomic and nomenclatural changes. As an example, Krishnan & Mishra (2001) reported seven species of Stolephorus from this estuary: S. andhraensis, S. baganensis, S. commersonii, S. dubiosus, S. indicus, S. insularis, and S. waitei. However, Hata et al. (2020, 2021) made several revisions to the genus Stolephorus including updating the species’ distribution records. The authors suggested the non-occurrence of S. baganensis, S. commersonii and S. waitei in India, thus making the records of these three species in the Godavari estuary questionable.

On the other hand, species including Plectorhinchus gibbosus, Diagramma pictum, and non-native species such as Oreochromis mossambicus and Piaractus brachypomus were recorded for the first time from this estuary. Moreover, the study by Krishnan & Mishra (2001) had a broader scope, having included other distributaries of Godavari River, in comparison to the current study whose focus was the Gowthami-Godavari system. Likewise, the number of species recorded in this study is relatively lower than other large estuaries or mangrove forests located on the east coast of India, including the Sundarbans mangroves (Bhattacharya et al. 2018) and Chilika Lake (Mohanty et al. 2015), from where 312 and 299 species have been recorded, respectively.

Many of the species recorded during this study have also been recorded from other Indian estuaries (Bijukumar & Sushama 2000; Ghosh et al. 2011; Mohanty et al. 2015; Bhattacharya et al. 2018; Sreekanth et al. 2020; Roshni et al. 2021). A number of freshwater species belonging to orders Cypriniformes and Siluriformes were recorded from the mangrove creeks. While a few of them, such as Mystus gulio and Etroplus suratensis (Image 7a) are known to occur in brackish water habitats (Bijukumar & Sushama 2000), the occurrence of carp species including Labeo rohita, L. calbasu, and L. fimbriatus were recorded in a few creeks during the post-monsoon season. This is the time when the mangrove forest gets flushed annually with sediment-laden fresh water from the river. The occurrence of these freshwater fishes in the mangrove creeks, however, may also be explained by the stocking of these species in aquaculture ponds abutting the mangroves, creeks, and canals across the East Godavari district. The number of species recorded from the mangrove-lined creeks (150 species), river mouth (151 species), and the Kakinada Bay (149 species) was similar. Nearly 67% of the total species occurred in at least two habitat types showing a high degree of overlap between the estuarine habitats of the delta. Of these, 64 species were found in all three habitat types. The high degree of overlap in species between the habitats indicates the importance of connectivity within this estuarine complex. Fishes recorded exclusively from the bay and the river mouth respectively, constituted nearly 16% and 11% of the total number of species recorded during this study.

Connectivity between the three estuarine habitats and the seascape of East Godavari district is crucial for migratory species occurring in the estuary. The flagship migratory species is Tenualosa ilisha, which undertakes large-scale migration from the sea into the Godavari River during the monsoon, when they contribute to important fisheries. It is popularly known as ‘Pulasa’ in Andhra Pradesh (or ‘Hilsa’ throughout the Indian sub-continent) and has high commercial value. Other important migratory species occurring in the estuary include Tenualosa toli, Anodontostoma chacunda, Lates calcarifer (Image 4a), and many eel species. Other species, such as mullets (Mugilidae), undertake migrations in the creeks on shorter temporal scales, mainly driven by the tidal regimes and food availability.

 

Threatened and exotic species

Four species recorded from this estuarine complex are assessed as threatened on the IUCN Red List. These include the Endangered Silonia childreni, and the Vulnerable Tenualosa toli, Cirrhinus cirrhosus and Wallago attu. The Godavari River is an important habitat for Silonia childreni, a highly threatened catfish species occurring in the large river systems of peninsular India. On multiple occasions, the authors recorded its distribution from various parts of the river stretch in Andhra Pradesh, including the estuarine part of the river. Despite this, catches of this large catfish species has been declining, as observed by the local fishers. Additionally, three Near Threatened species: Ompok bimaculatus, Harpadon nehereus, & Protonibea diacanthus and 10 Data Deficient species: Platycephalus indicus, Epinephelus tauvina, Acanthopagrus datnia, Rastrelliger kanagurta, Scomberomorus guttatus, Parapocryptes rictuosus, Taenioides cirratus, Psettodes erumei, Cynoglossus arel, & Megalops cyprinoides were recorded during this study (Table 2). Of the 10 Data Deficient species, P. indicus was among the more commonly occurring species in the estuary, which was recorded from all the three habitat types during this study. The two eel species, Parapocryptes rictuosus and Taenioides cirratus, were recorded only on one occasion in a fisher’s catch from the mangrove creek of Tulyabagha inside the CWS.

Five exotic species were also recorded during this study. These include Oreochromis mossambicus, O. niloticus, Ctenopharyngodon idella, Cyprinus carpio, and Piaractus brachypomus. The first four species are recognized as worst invasive species’ of the world by the IUCN Global Invasive Species Database (2021) due to their negative impacts on native fauna. Alarmingly, O. mossambicus was found to be among the most dominant species in the CWS. This species appeared to have established a self-sustaining wild population within the Thulyabagha and Coringa creeks of the sanctuary, where the salinities annually ranged from 2 ppt to 20 ppt. The remaining exotic species were recorded only from the riverine zone of the estuary complex.

The main pathway of exotic fish introduction is likely to be through the aquaculture ponds that stock these exotic species. Piaractus brachypomus (Pirapitinga), a native of South America, was first recorded from the fish landing centre by the authors in 2013. Since then, this species has become a popular fish in the region (and across the country) and is being extensively stocked in aquaculture ponds along the river, mangrove creeks and canals. It is commonly sold in the local fish markets under the guise of ‘white pomfret’ or ‘freshwater pomfret’ and is even being recorded in the catches made by the local fishers in the river (Paromita Ray and Giridhar Malla pers. obs.). This could indicate its possible escape from the aquaculture farms into, and possible establishment within, the river. The authors also noted two occurrence records of Pterygoplichthys sp. (family Loricariidae) from the freshwater upstream zone of the river in the East Godavari district. Local fishers recorded this species during the flood season.

 

Major threats

The Godavari River delta and the estuarine complex have been greatly altered by human activities. The Godavari River delta, along with the Krishna River delta to its south, constitutes one of the largest offshore natural gas reserves in India. The Kakinada Bay also acts as a natural harbour as well as an important port for the state. Additionally, the industrial city of Kakinada (also the headquarters of the East Godavari district) is located adjacent to the mangroves and the estuary. Some of the main causes for degradation of the estuarine ecosystems and the mangrove forests include: diversion for aquaculture, agriculture, salt pans and industries; and rapid and unplanned urbanization (Jayanthi et al. 2018; Bagaria et al. 2021). Other threats include discharge of untreated effluents from anthropogenic sources such as aquaculture farms and industries into the river, canals and the mangrove creeks (Rao et al. 2018); sand mining at the river bed, dredging of the creeks and river mouth (Malini & Rao 2004) alteration of the natural flow of Godavari River and obstructing freshwater discharge and sediment load into the estuary and mangroves (Malini & Rao 2004). Large-scale deforestation and loss of aquatic habitats in the upper catchments of Godavari River, such as that found in and around the Papikonda National Park (Aditya & Ganesh 2019) which is ~80 km upstream of the estuary, also exacerbates the negative impacts on the estuarine biodiversity.

During the present study, we noticed a number of aquaculture ponds located very close to the mangrove forests, and adjoining the feeder creeks and canals (Image 2). This not only increases the risk of release of exotic fishes and causes degradation of the fringe mangroves, but also increases the risk of introduction of disease in the wild fish community. During the study period, two instances of fish kills were also observed in the Coringa creek draining into the CWS. On further enquiry by the authors, the local fishers informed us that fish kills have become a regular occurrence in the creeks due to the release of untreated effluents by the aquaculture ponds and the industries located upstream. The coastal zones of the East Godavari district are considered among the most polluted in the state (Muktha et al. 2018).

The mangroves of CWS are well-protected and support a diverse aquatic community. However, the mangrove patches at the edge of the sanctuary or the unprotected patches in the district are highly vulnerable to loss and conversion to other land uses, including aquaculture and industries. Bagaria et al. (2021) estimated a loss of 5.81 sq. km of unprotected mangroves in the delta between 1977 and 2015, complemented with a simultaneous rise of 177 km2 in the area under aquaculture. The study has also highlighted the rapid increase in human settlements and industries and a loss of other natural coastal features, including coastal scrub, mudflats, and riverine vegetation. A recent report by Rao (2021) inferred that an unprotected patch of mangrove drained by a creek near Kakinada harbour had been reported to be reclaimed for city development.

As the unprotected mangroves on the landward side are being lost to land-use changes, climate change is driving mangrove loss on the seaward side of the delta. An estimated 15 km2 of mangroves in the East Godavari district have been lost due to sea-level rise between 1977 and 2015 (Bagaria et al. 2021). Visible signs of seaward changes, including degradation and intrusion of sand into the mangrove forests, were also observed by the authors during the present study (Image 3). This region is also among the coastal stretches of India that are most vulnerable to natural disasters including cyclones and storm surges (Mohapatra et al. 2012). The effects of sea-level rise compounded with the increasing degradation and conversion of the mangroves on the landward side is possibly driving them towards a situation of ‘mangrove squeeze’.

In addition to the above threats, regulation of the Godavari River driven by the Polavaram Dam, a large dam being constructed nearly 100 km upstream of the river mouth, will potentially lead to drastic reductions in freshwater and sediment flow into the mangroves and the estuary. Studies from Portugal (Chicharo et al. 2006), China (Jiao et al. 2007) and other parts of the world have shown the negative impacts of damming on estuaries and marine habitats, including changes in salinity regime, nutrient flow, primary productivity and the fish community. Ezcurra et al. (2019) found a rapid coastal recession in otherwise accreting tropical river basins after they were dammed, coupled with losses in fisheries and other ecosystem services. With the presence of nine large dams and a number of smaller dams and irrigation projects, the Godavari River is a highly regulated river system of India. The annual sediment flux in the river basin has already decreased by an estimated 74% (Gupta et al. 2012). The Polavaram Dam has a high likelihood of exacerbating the downstream impacts by restricting the sediment discharge and further altering the freshwater flow regime, both of which play important roles in the sustenance of the mangroves as well as in structuring the estuarine fish assemblages. It will, therefore, be crucial to regularly monitor the estuary and its fish community once the dam becomes functional in the near future.

 

 

Conclusion and Recommendations

 

This study documented the rich finfish diversity of the dynamic Godavari River estuarine complex. This estuary complex, formed by India’s largest peninsular river, is undergoing rapid changes driven by number of anthropogenic factors coupled with sea-level rise, coastal erosion and natural disasters including cyclones. While the protected mangroves of the CWS do provide a crucial refuge for estuarine and juvenile marine fishes, it is important to adopt a holistic and prescient approach to protect the unprotected coastal habitats of the region. As this study suggests, various fish species are utilizing the different estuarine habitats of the Godavari delta. Few migratory and conservation-concern species such as the ‘Hilsa’ or ‘Pulasa’ have also been recorded in this estuary. Therefore, to better manage the threats, and to protect the aquatic ecosystems of the East Godavari district, it is crucial to understand and acknowledge the importance of maintaining the ecological connectivity, both between and within the riverscape and the various estuarine habitats, including the river mouth, the mangrove-lined creeks and the bay. The information collected in this study will serve as a baseline to monitor future changes in the fish community of this region, driven by various anthropogenic and natural stressors.

The Polavaram Dam is already under construction, but it is still important to focus on mitigating the negative impacts on the riverine habitats, both upstream and downstream. The minimum freshwater flows to the downstream habitats must be ensured by the dam authorities, taking in consideration the river’s natural pattern of seasonal variation in freshwater discharge. Alongside this, it is also important to recognize the negative impacts of stocking and introduction of non-native fish species as a mitigation measure. Several non-native species have been recorded in this study that were introduced either through fisheries or accidentally through aquaculture and the aquarium industry. The district authorities and the fisheries department need to take immediate steps to address this issue, while strictly prohibiting the stocking of non-native fishes in the reservoir, canals or aquaculture ponds in the district. The fisheries department can encourage protection of the carp and catfish species that are native to the Godavari River basin such as the threatened Silonia childreni.

We recommend mapping of the unprotected and degraded patches of mangroves in the delta region of the district that serve as important nursery habitats for the fish species. This would help in identifying and prioritizing the most vulnerable stretches for focused conservation efforts. Declaring the most degraded and vulnerable mangroves as ‘eco-sensitive zones’ or ‘community reserves’ would provide them with basic protection from future conversions and losses. The authorities may follow this with restoration of the degraded mangrove patches. A similar prioritization exercise should also be carried out for other coastal habitats of the estuary, including the unprotected creeks, intertidal zones, mudflats, river banks and the river mouth.

Additionally, a minimum buffer should be allowed around the mangrove forests and the creeks on the landward side to allow them to maintain their structural integrity and landward shift driven by sea-level rise. The aquaculture ponds should particularly be located at a minimum distance away from the mangrove forests and the creeks. Strict monitoring of the ponds, as per the guidelines prescribed by the Coastal Aquaculture Authority of India, should be carried out to prevent untreated effluent discharge and release of non-native species into the natural habitats. Since the area under aquaculture in the district continues to grow each year, a scientific study is recommended that would assess the ecological capacity of this estuarine region to support this industry along with assessing the extant negative ecological and socio-economic impacts of the same. The policies pertaining to captive fisheries should actively encourage sustainable aquaculture practices rather than focusing on maximization of short-term economic gains.    

The district authorities should also enhance monitoring of destructive activities in the river basin such as sand-mining, deforestation of the riparian zones, and conversion of river banks to other land-uses. In addition, the government should especially take actions to stop illegal mining of the river bed in the district, proactively monitor the pollution levels in the river, mangroves, and the associated creeks and canals and initiate action against the industries and aquaculture ponds found releasing untreated effluents into the estuary, as prescribed by law.

Garnering the support of local communities and other stakeholders is crucial for the long-term conservation and management of the Godavari estuarine complex and its associated biodiversity. For generating local support, district and village-level organizations such as the panchayat, self-help groups, fishers’ collectives, and aquaculture collectives can be leveraged. Regular and focused campaigns would be helpful to improve awareness as well as generating local stewardship for sustainable fisheries and biodiversity conservation. Such awareness programs should also be developed for policy makers, planners, and stakeholders from the agricultural and industrial sectors since their actions may also have serious impacts on the aquatic ecosystems of the district. Along with this, further inter-disciplinary studies are important to understand the different features of this estuarine complex including biological, ecological, social, cultural, and economic complexities.

  

 

Table 1. Habitat-wise list of finfish species recorded during this study from the Godavari River estuary complex.

 

Order

Family

Species

Main River

Mangroves

Kakinada Bay

1

Elopiformes

Elopidae

Elops machnata (Fabricius, 1775) (Image 5e)

0

1

0

2

 

Megalopidae

Megalops cyprinoides (Broussonet, 1782)

1

1

1

3

Anguilliformes

Muraenidae

Strophidon sathete (Hamilton, 1822)

1

1

0

4

 

Ophichthidae

Bascanichthys deraniyagalai Menon, 1961

1

1

1

5

 

 

Cirrhimuraena playfairii (Günther, 1870)

1

1

0

6

 

 

Pisodonophis boro (Hamilton, 1822)

1

1

0

7

 

 

Pisodonophis cancrivorus (Richardson, 1848)

1

1

0

8

 

Muraenescocidae

Congresox talabonoides (Bleeker, 1852)

1

1

0

9

 

 

Congresox talabon (Cuvier, 1829)

1

1

0

10

 

 

Muraenesox cinereus (Forsskål, 1775)

1

1

0

11

 

 

Muraenesox bagio (Hamilton, 1822)

1

1

0

12

 

Congridae

Uroconger lepturus (Richardson, 1845)

1

0

0

13

 

Moringuidae

Moringua raitaborua (Hamilton, 1822)

1

1

1

14

Osteoglossiformes

Notopteridae

Notopterus notopterus (Pallas, 1769)

1

0

0

15

Clupeiformes

Clupeidae

Anodontostoma chacunda (Hamilton, 1822)

1

1

0

16

 

 

Escualosa thoracata (Valenciennes, 1847)

1

1

1

17

 

 

Hilsa kelee (Cuvier, 1829)

1

1

1

18

 

 

Nematalosa nasus (Bloch, 1795)

1

0

0

19

 

 

Sardinella longiceps Valenciennes, 1847

1

1

1

20

 

 

Sardinella fimbriata (Valenciennes, 1847)

1

1

1

21

 

 

Tenualosa ilisha (Hamilton, 1822)

1

0

0

22

 

 

Tenualosa toli (Valenciennes, 1847)

1

1

0

23

 

Dussumieriidae

Dussumieria acuta Valenciennes, 1847

0

1

1

24

 

 

Dussumieria elopsoides Bleeker, 1849

0

1

1

25

 

Engraulidae

Coilia dussumieri Valenciennes, 1848

1

1

1

26

 

 

Coilia reynaldi Valenciennes, 1848

1

1

1

27

 

 

Setipinna taty (Valenciennes, 1848)

1

1

1

28

 

 

Setipinna tenuifilis (Valenciennes, 1848)

1

1

1

29

 

 

Stolephorus commersonnii Lacepède, 1803

1

1

1

30

 

 

Stolephorus indicus (van Hasselt, 1823)

0

0

1

31

 

 

Thryssa mystax (Bloch & Schneider, 1801)

1

1

1

32

 

 

Thryssa malabarica (Bloch, 1795)

1

1

1

33

 

 

Thryssa baelama (Fabricius, 1775)

1

1

1

34

 

Chirocentridae

Chirocentrus dorab (Fabricius, 1775)

1

0

1

35

 

Pristigasteridae

Ilisha melastoma (Bloch & Schneider, 1801)

1

1

1

36

 

 

Ilisha megaloptera (Swainson, 1838)

1

1

1

37

 

 

Opisthopterus tardoore (Cuvier, 1829)

(Image 4c)

1

1

1

38

 

 

Pellona ditchela Valenciennes, 1847

1

1

1

39

 

 

Raconda russeliana Gray, 1831

1

0

1

40

Gonorynchiformes

Chanidae

Chanos chanos (Fabricius, 1775)

1

0

1

41

Cypriniformes

Cyprinidae

Cirrhinus cirrhosus (Bloch, 1795)

1

1

0

42

 

 

Cirrhinus mrigala (Hamilton, 1822)

1

0

0

43

 

 

Cyprinus carpio Linnaeus, 1758

1

0

0

44

 

 

Labeo catla (Hamilton, 1822)

1

0

0

45

 

 

Labeo calbasu (Hamilton, 1822)

1

1

0

46

 

 

Labeo fimbriatus (Bloch, 1795)

1

1

0

47

 

 

Labeo rohita (Hamilton, 1822)

1

1

0

48

 

 

Puntius sophore (Hamilton, 1822)

1

1

0

49

 

 

Pethia ticto (Hamilton, 1822)

1

0

0

50

 

Xenocyprididae

Ctenopharyngodon idella (Valenciennes, 1844)

1

0

0

51

Characiformes

Serrasalmidae

Piaractus brachypomus (Cuvier, 1818)

1

0

0

52

Siluriformes

Plotosidae

Plotosus canius Hamilton, 1822

1

1

0

53

 

 

Plotosus lineatus (Thunberg, 1787)

0

0

1

54

 

Ailiidae

Silonia childreni (Sykes, 1839)

1

0

0

55

 

Bagridae

Mystus gulio (Hamilton, 1822)

1

1

0

56

 

 

Mystus vittatus (Bloch, 1794)

1

1

0

57

 

Pangasiidae

Pangasius pangasius (Hamilton, 1822)

1

1

0

58

 

Siluridae

Wallago attu (Bloch & Schneider, 1801)

1

0

0

59

 

 

Ompok bimaculatus (Bloch, 1794)

1

0

0

60

 

Heteropneustidae

Heteropneustes fossilis (Bloch, 1794)

1

1

0

61

 

Ariidae

Arius arius (Hamilton, 1822)

1

1

1

62

 

 

Arius gagora (Hamilton 1822)

1

1

1

63

 

 

Arius maculatus (Thunberg, 1792)

1

1

1

64

 

 

Plicofollis dussumieri (Valenciennes, 1840)

0

0

1

65

Aulopiformes

Synodontidae

Saurida tumbil (Bloch, 1795)

0

0

1

66

 

 

Synodus indicus (Day, 1873)

0

0

1

67

 

 

Harpadon nehereus (Hamilton, 1822)

1

1

1

68

Batrachoidiformes

Batrachoididae

Allenbatrachus grunniens (Linnaeus, 1758) (Image 7c)

1

1

0

69

Scombriformes

Scombridae

Katsuwonus pelamis (Linnaeus, 1758)

0

0

1

70

 

 

Rastrelliger kanagurta (Cuvier, 1816)

1

0

1

71

 

 

Scomberomorus guttatus (Bloch & Schneider, 1801)

0

0

1

72

 

Trichiuridae

Eupleurogrammus muticus (Gray, 1831)

1

1

0

73

 

 

Lepturacanthus savala (Cuvier, 1829)

1

0

1

74

 

 

Trichiurus lepturus Linnaeus, 1758

1

0

1

75

Syngnathiformes

Mullidae

Upeneus sulphureus Cuvier, 1829

1

1

1

76

 

 

Upeneus vittatus (Forsskål, 1775)

1

0

0

77

 

 

Upeneus moluccensis (Bleeker, 1855)

0

0

1

78

 

 

Upeneus taeniopterus Cuvier, 1829

1

1

1

79

 

Callionymidae

Callionymus carebares Alcock, 1890

0

1

0

80

Kurtiformes

Kurtidae

Kurtus indicus Bloch, 1786 (Image 7d)

0

1

1

81

 

Apogonidae

Jaydia queketti (Gilchrist 1903) (Image 6d)

0

0

1

82

Gobiiformes

Eleotridae

Eleotris fusca (Bloch & Schneider, 1801)

1

1

0

83

 

 

Butis butis (Hamilton, 1822) (Image 5d)

0

1

0

84

 

 

Butis humeralis (Valenciennes, 1837)

0

1

0

85

 

Gobiidae

Aulopareia cyanomos (Bleeker, 1849) (Image 5b)

0

1

1

86

 

 

Apocryptes bato (Hamilton, 1822)

0

1

0

87

 

 

Boleophthalmus boddarti (Pallas, 1770)

0

1

1

88

 

 

Glossogobius giuris (Hamilton, 1822)

1

1

0

89

 

 

Oxyurichthys microlepis (Bleeker, 1849) (Image 7b)

0

1

0

90

 

 

Parapocryptes rictuosus (Valenciennes, 1837)

0

1

0

91

 

 

Periophthalmus chrysospilos Bleeker, 1853

0

1

0

92

 

 

Taenioides anguillaris (Linnaeus, 1758)

1

1

0

93

 

 

Taenioides cirratus (Blyth, 1860)

1

1

0

94

 

 

Trypauchen vagina (Bloch & Schneider, 1801) (Image 6e)

1

1

0

95

 

 

Yongeichthys nebulosus (Forsskål, 1775)

1

0

0

96

 

 

Stigmatogobius sadanundio (Hamilton, 1822)

1

0

0

97

Synbranchiformes

Mastacembelidae

Macrognathus pancalus Hamilton 1822

1

0

0

98

 

Synbranchidae

Ophisternon bengalense McClelland, 1844

1

0

0

99

Anabantiformes

Anabantidae

Anabas testudineus (Bloch, 1792)

1

1

0

100

 

Osphronemidae

Trichogaster fasciata Bloch & Schneider, 1801

1

0

0

101

 

Channidae

Channa punctata (Bloch, 1793)

1

0

0

102

 

 

Channa striata (Bloch, 1793)

1

0

0

103

 

Nandidae

Nandus nandus (Hamilton, 1822)

0

1

0

104

Carangiformes

Latidae

Lates calcarifer (Bloch, 1790) (Image 4a)

1

1

0

105

 

Lactariidae

Lactarius lactarius (Bloch & Schneider, 1801)

1

0

1

106

 

Sphyraenidae

Sphyraena obtusata Cuvier, 1829

0

0

1

107

 

 

Sphyraena jello Cuvier, 1829

0

0

1

108

 

Polynemidae

Eleutheronema tetradactylum (Shaw, 1804)

1

1

1

109

 

 

Polydactylus sextarius (Bloch & Schneider, 1801)

1

1

1

110

 

 

Leptomelanosoma indicum (Shaw, 1804)

1

1

1

111

 

Psettodidae

Psettodes erumei (Bloch & Schneider, 1801)

1

0

1

112

 

Bothidae

Bothus myriaster (Temminck & Schlegel, 1846)

0

1

1

113

 

Paralichthyidae

Pseudorhombus arsius (Hamilton, 1822)

0

1

1

114

 

 

Pseudorhombus triocellatus (Bloch & Schneider, 1801)

0

1

1

115

 

 

Pseudorhombus elevatus Ogilby, 1912

1

1

1

116

 

Soleidae

Aesopia cornuta Kaup, 1858

0

0

1

117

 

 

Solea ovata Richardson, 1846

0

1

1

118

 

 

Dagetichthys albomaculatus (Kaup, 1858)

1

1

1

119

 

 

Zebrias synapturoides (Jenkins, 1910)

1

1

1

120

 

Cynoglossidae

Cynoglossus arel (Bloch & Schneider, 1801)

1

1

1

121

 

 

Cynoglossus bilineatus (Lacepède, 1802)

1

1

1

122

 

 

Cynoglossus puncticeps (Richardson, 1846)

1

1

1

123

 

 

Cynoglossus lingua Hamilton, 1822

1

1

0

124

 

 

Cynoglossus cynoglossus (Hamilton, 1822)

1

1

1

125

 

 

Paraplagusia bilineata (Bloch, 1787)

1

1

1

126

 

Menidae

Mene maculata (Bloch & Schneider, 1801)

0

1

0

127

 

Carangidae

Megalaspis cordyla (Linnaeus, 1758)

0

0

1

128

 

 

Scyris indica (Rüppell, 1830)

1

0

1

129

 

 

Alepes djedaba (Fabricius, 1775)

1

0

1

130

 

 

Alepes kleinii (Bloch, 1793)

1

0

1

131

 

 

Atropus atropos (Bloch & Schneider, 1801)

0

0

1

132

 

 

Atule mate (Cuvier, 1833)

1

0

1

133

 

 

Platycaranx malabaricus (Bloch & Schneider, 1801)

0

0

1

134

 

 

Caranx ignobilis (Forsskål, 1775)

0

1

1

135

 

 

Caranx sexfasciatus Quoy & Gaimard, 1825

0

1

1

136

 

 

Caranx heberi (Bennett, 1830)

0

0

1

137

 

 

Decapterus russelli (Rüppell, 1830)

0

0

1

138

 

 

Parastromateus niger (Bloch, 1795)

0

1

1

139

 

 

Scomberoides commersonnianus Lacepède, 1801

0

0

1

140

 

 

Scomberoides tol (Cuvier, 1832)

0

0

1

141

 

 

Selar crumenophthalmus (Bloch, 1793)

0

0

1

142

 

 

Trachinotus mookalee Cuvier, 1832.

(Image 6a)

0

1

1

143

 

Rachycentridae

Rachycentron canadum (Linnaeus, 1766)

0

0

1

144

Cichliformes

Ambassidae

Ambassis gymnocephalus (Lacepède, 1802)

1

1

0

145

 

 

Chanda nama Hamilton, 1822

1

1

0

146

 

Cichlidae

Etroplus suratensis (Bloch, 1790)

(Image 7a)

1

1

0

147

 

 

Pseudetroplus maculatus (Bloch, 1795)

1

0

0

148

 

 

Oreochromis mossambicus (Peters, 1852)

1

1

0

149

 

 

Oreochromis niloticus (Linnaeus, 1758)

1

0

0

150

Cyprinodontiformes

Aplocheilidae

Aplocheilus blockii Arnold, 1911

1

1

0

151

 Beloniformes

Belonidae

Strongylura strongylura (van Hasselt, 1823)

1

0

1

152

 

 

Xenentodon cancila (Hamilton, 1822)

1

1

0

153

 

Hemiramphidae

Hyporhamphus limbatus (Valenciennes, 1847)

1

1

1

154

 

Adrianichthyidae 

Oryzias dancena (Hamilton 1822)

0

1

0

155

Mugiliformes

Mugilidae

Mugil cephalus Linnaeus, 1758

1

1

1

156

 

 

Chelon parsia (Hamilton, 1822)

1

1

1

157

 

 

Planiliza subviridis (Valenciennes, 1836)

1

1

1

158

 

 

Planiliza planiceps (Valenciennes, 1836)

1

0

0

159

 

 

Planiliza tade (Fabricius, 1775)

1

1

0

160

 

 

Rhinomugil corsula (Hamilton, 1822)

1

1

0

161

 

 

Crenimugil seheli (Fabricius, 1775)

1

1

1

162

Blenniiformes

Blenniidae

Omobranchus ferox (Herre, 1927)

1

1

0

163

Perciformes *sedis mutabilis*

Sillaginidae

Sillaginopsis domina (Cuvier, 1816)

0

0

1

164

 

 

Sillago sihama (Fabricius, 1775)

1

1

1

165

 

Lutjanidae

Lutjanus johnii (Bloch, 1792) (Image 4b)

1

1

1

166

 

 

Lutjanus russellii (Bleeker, 1849)

0

1

1

167

 

 

Lutjanus argentimaculatus (Forsskål, 1775) (Image 5c)

0

1

1

168

 

 

Lutjanus fulviflamma (Forsskål, 1775)

0

1

1

169

 

Gerreidae

Gerres filamentosus Cuvier, 1829

1

1

1

170

 

 

Gerres limbatus Cuvier, 1830

1

1

1

171

 

 

Gerres setifer (Hamilton, 1822)

1

1

1

172

 

 

Gerres oyena (Fabricius, 1775)

1

1

1

173

 

 

Gerres longirostris (Lacepède, 1801)

0

0

1

174

 

Haemulidae

Pomadasys kaakan (Cuvier, 1830)

1

1

1

175

 

 

Pomadasys argenteus (Forsskål, 1775)

1

1

1

176

 

 

Pomadasys maculatus (Bloch, 1793)

1

1

1

177

 

 

Plectorhinchus gibbosus (Lacepède, 1802)

0

0

1

178

 

 

Diagramma pictum (Thunberg, 1792)

0

0

1

179

 

Sparidae

Acanthopagrus berda (Fabricius, 1775)

0

0

1

180

 

 

Acanthopagrus datnia (Hamilton, 1822)

0

0

1

181

 

 

Rhabdosargus sarba (Gmelin, 1789)

0

0

1

182

 

Sciaenidae

Chrysochir aurea (Richardson, 1846)

0

1

1

183

 

 

Daysciaena albida (Cuvier, 1830)

0

1

1

184

 

 

Dendrophysa russelii (Cuvier, 1829)

1

1

1

185

 

 

Johnius belangerii (Cuvier, 1830)

0

1

1

186

 

 

Johnius coitor (Hamilton, 1822)

1

1

1

187

 

 

Johnius dussumieri (Cuvier, 1830)

0

1

1

188

 

 

Kathala axillaris (Cuvier, 1830)

0

1

1

189

 

 

Nibea maculata (Bloch & Schneider, 1801)

0

1

1

190

 

 

Nibea soldado (Lacepède, 1802)

0

1

1

191

 

 

Otolithes ruber (Bloch & Schneider, 1801)

1

1

0

192

 

 

Panna microdon (Bleeker, 1849)

0

1

1

193

 

 

Protonibea diacanthus (Lacepède, 1802)

0

1

1

194

Perciformes

Epinephelidae

Epinephelus coioides (Hamilton, 1822)

0

1

1

195

 

 

Epinephelus malabaricus (Bloch & Schneider, 1801)

0

1

1

196

 

 

Epinephelus melanostigma Schultz, 1953

0

0

1

197

 

 

Epinephelus tauvina (Fabricius, 1775)

0

0

1

198

 

Platycephalidae

Grammoplites scaber (Linnaeus, 1758)

1

1

0

199

 

 

Cociella crocodilus (Cuvier, 1829)

1

0

0

200

 

 

Platycephalus indicus (Linnaeus, 1758)

1

1

1

201

 

Triglidae

Lepidotrigla sp.

0

0

1

202

 

Synanceiidae

Minous monodactylus (Bloch & Schneider, 1801) (Image 4f)

0

1

1

203

 

 

Minous inermis Alcock 1889

0

0

1

204

Centrarchiformes

Terapontidae

Terapon jarbua (Fabricius, 1775) (Image 6c)

1

1

0

205

 

 

Terapon puta Cuvier, 1829

1

1

0

206

 

 

Pelates quadrilineatus (Bloch, 1790)

1

0

1

207

Acanthuriformes

Lobotidae

Lobotes surinamensis (Bloch, 1790)

1

0

1

208

 

Drepaneidae

Drepane longimana (Bloch & Schneider, 1801)

1

1

0

209

 

 

Drepane punctata (Linnaeus, 1758)

0

1

0

210

 

Ephippidae

Ephippus orbis (Bloch, 1787)

0

0

1

211

 

 

Platax sp.

0

0

1

212

 

Leiognathidae

Leiognathus equula (Forsskål, 1775)

1

1

1

213

 

 

Eubleekeria splendens (Cuvier, 1829)

1

1

1

214

 

 

Leiognathus berbis (Valenciennes, 1835)

0

1

1

215

 

 

Photopectoralis bindus (Valenciennes, 1835)

1

1

1

216

 

 

Gazza minuta (Bloch, 1795)

0

0

1

217

 

 

Deveximentum insidiator (Bloch, 1787)

1

1

1

218

 

 

Nuchequula blochii (Valenciennes, 1835)

0

1

1

219

 

 

Leiognathus ruconius (Hamilton, 1822) (Image 4d)

1

1

1

220

 

Scatophagidae

Scatophagus argus (Linnaeus, 1766)

1

1

1

221

 

Siganidae

Siganus canaliculatus (Park, 1797)

1

1

1

222

 

 

Siganus javus (Linnaeus, 1766) (Image 4e)

1

1

1

223

 

Acanthuridae

Acanthurus mata (Cuvier, 1829) (Image 5a)

1

0

0

224

 

 

Acanthurus xanthopterus Valenciennes, 1835

1

1

1

225

Tetraodontiformes

Triacanthidae

Triacanthus biaculeatus (Bloch, 1786) (Image 6b)

0

0

1

226

 

Tetraodontidae

Takifugu oblongus (Bloch, 1786)

0

0

1

227

 

 

Chelonodontops patoca (Hamilton, 1822)

1

1

1

228

 

 

Dichotomyctere fluviatilis (Hamilton, 1822)

1

1

1

229

 

 

Lagocephalus lunaris (Bloch & Schneider, 1801)

1

0

1

230

 

 

Lagocephalus inermis (Temminck & Schlegel, 1850)

1

0

1

231

 

Monacanthidae

Aluterus monoceros (Linnaeus, 1758)

0

0

1

 

 

 

Total

151

150

149

1—Presence recorded | 0—Presence not recorded.

 

 

Table 2. List of threatened, Near Threatened, and Data Deficient species as per the IUCN Red List of Threatened Species.

 

Species name

Main river

Mangroves

Bay

IUCN Red List status

1

Silonia childreni (Sykes, 1839)

+

-

-

EN

2

Tenualosa toli (Valenciennes, 1847)

+

+

-

VU

3

Cirrhinus cirrhosus (Bloch, 1795)

+

+

-

VU

4

Wallago attu (Bloch & Schneider, 1801)

+

-

-

VU

5

Ompok bimaculatus (Bloch, 1794)

+

-

-

NT

6

Harpadon nehereus (Hamilton, 1822)

+

+

+

NT

7

Protonibea diacanthus (Lacepède, 1802)

-

+

+

NT

8

Platycephalus indicus (Linnaeus, 1758)

+

+

+

DD

9

Epinephelus tauvina (Fabricius, 1775)

-

-

+

DD

10

Acanthopagrus datnia (Hamilton, 1822)

-

-

+

DD

11

Rastrelliger kanagurta (Cuvier, 1816)

+

-

+

DD

12

Scomberomorus guttatus (Bloch & Schneider, 1801)

-

-

+

DD

13

Parapocryptes rictuosus (Valenciennes, 1837)

-

+

-

DD

14

Taenioides cirratus (Blyth, 1860)

+

+

-

DD

15

Psettodes erumei (Bloch & Schneider, 1801)

+

-

+

DD

16

Cynoglossus arel (Bloch & Schneider, 1801)

+

+

+

DD

17

Megalops cyprinoides (Broussonet, 1782)

+

+

+

DD

+—Presence recorded | ——Presence not recorded | EN—Endangered | VU—Vulnerable | NT—Near Threatened | DD—Data Deficient.

 

 

For figures & images - - click here for full PDF

 

 

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Rao, M.B. (1965). Biological studies on the gizzard shad Anodontostoma chacunda Hamilton (Family: Clupeidae), Journal of the Marine Biological Association of India 7: 89–101.

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