Journal of Threatened
Taxa | www.threatenedtaxa.org | 26 February 2025 | 17(2): 26504–26514
ISSN 0974-7907 (Online)
| ISSN 0974-7893 (Print)
https://doi.org/10.11609/jott.9181.17.2.26504-26514
#9181 | Received 02 June
2024 | Final received 30 January 2025 | Finally accepted 07 February 2025
Checklist on the
ichthyofaunal resources and conservation status of
Dikhu River, Nagaland,
India
Metevinu Kechu
1 & Pranay Punj Pankaj 2
1,2 Department of
Zoology, Nagaland University, Hqrs: Lumami, Zunheboto District,
Nagaland 798627, India.
1 metevinu06@gmail.com,
2 pranaypunj@gmail.com (corresponding author)
Editor: Yahya Bakhtiyar,
University of Kashmir, Srinagar, India. Date of publication: 26 February
2025 (online & print)
Citation: Kechu, M. & P.P. Pankaj (2025). Checklist on the ichthyofaunal resources
and conservation status of Dikhu River, Nagaland,
India. Journal of Threatened Taxa 17(2):
26504–26514. https://doi.org/10.11609/jott.9181.17.2.26504-26514
Copyright: © Kechu & Pankaj 2025. 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: ICAR-National Bureau of Fish Genetic Resources, Lucknow (Project No.: G./NE/2015).
Competing interests: The authors declare no competing interests.
Author details: Metevinu Kechu is a research scholar and is actively engaged in ichthyofaunal exploration and documentation in Nagaland. Pranay Punj Pankaj is engaged in teaching fisheries as well as research and development activities on the subject in the region.
Author contributions: MK surveyed the Dikhu River of Nagaland and confirmation of the identity of the species. PPP supervised the work and interpreted the taxonomic information gathered by the Mk.
Acknowledgements: PPP gratefully acknowledges the financial support from ICAR-National Bureau of Fish Genetic Resources, Lucknow.
Abstract: Dikhu River constitutes one of the major perennial rivers
of Nagaland and due to its pristine beauty aids as a tourism spot. From the
present study, ichthyofaunal diversity accounted for a total of 28 fish species
belonging to 6 orders, 13 families, and 3 subfamilies. From the investigation,
order Cypriniformes (67.9%) was found to be the most
dominant, followed by Siluriformes (14.3%) and Anabantiformes (7.1%) while order Beloniformes,
Synbranchiformes and Anguilliformes was found to be
the least common with 10.7% in total. The IUCN red list of threatened species
shows 71.4% are Least Concern, 7.1% Near Threatened, 3.6% Vulnerable, 3.6%
Endangered, 10.7% Not Accessed and 3.6% Data Deficient. IUCN population status
data shows that 57.1% are unknown, 10.7% stable, 10.7% not accessed, and 21.4%
with decreasing population trends. Diversity indices (Shannon, Simpson, and
Evenness) indices ranged 2.497–2.912, 0.892–0.936, and 0.820–0.908,
respectively. Relative abundance determinations ranged from a high of 15.55%
for Devario aequipinnatus
to the lowest values for Tariqilabeo latius and Botia rostrata at 0.08%. Anthropogenic pressure on the Dikhu River has resulted in habitat modification and
fragmentation, posing a hazard to fish diversity. Fish abundance was found to
be highest in the post-monsoon season and lowest in winter. These findings are
significant for academic purposes and support conservation strategies for local
fish resources.
Keywords: Assessment,
biodiversity, diversity index, fish species, fisheries management,
ichthyofauna, Nagaland fisheries, population status, riverine habitat,
threatened species.
INTRODUCTION
India has been identified as one of the mega
biodiversity countries in the world (Mittermeier & Mitemeir
1997) and the northeastern part of India with its
unique topography has been considered a biodiversity hotspot in the world (Groombridge & Jenkins 1998). The region’s rich
biodiversity is attributed to its tectonic placement (Kottelat
1989) and is considered a freshwater fish biodiversity hotspot in the world (Kottelat et al. 1996).
The state of Nagaland, located in the northeastern part of India, is known for its rich
biodiversity, including a diverse range of fish species. Nagaland is bounded by
beautiful hilly terrain and riverine system and shares boundaries with Assam
(northern and western part), Arunachal Pradesh (northeastern
part), Myanmar (eastern part), and Manipur (southern) (Kosygin & Vishwanath
1998). The three principal drainages of Nagaland consist of Brahmaputra and
Barack of Indian origin and Chindwin drainage of Indo-Burma origin. The Dikhu River, flowing through Nagaland, serves as a prime
location to study the ichthyofaunal diversity in the region. This river is
characterized by its running waters and hilly terrain, making it an ideal
habitat for various fish species. Furthermore, little information exists on the
biology of these fish species, emphasizing the need for a comprehensive study
of their diversity. The study of fish diversity in the Dikhu
River would provide valuable insights into the ecological dynamics and
conservation efforts in the region.
Biodiversity hotspots under freshwater
ecosystems, are increasingly under threat, making their conservation a critical
concern. Major factors such as habitat destruction, invasive species,
overexploitation, and the impacts of climate change are driving the rapid
decline of species populations. Studies have highlighted that approximately 24%
of freshwater species are facing a high risk of extinction due to threats
including pollution, dam construction, water extraction, agricultural
practices, and the introduction of invasive species (Sayer et al. 2025). In the
northeastern region of India, studies have provided
valuable insights into the conservation status of freshwater fish species,
illustrating both the rich diversity and the significant threats they face
(Vishwanath 2017). A report presented at COP 28 in the United Arab Emirates
further revealed that 25% of freshwater fish species worldwide are at risk of
extinction, with climate change directly impacting at least 17% of these
species (IUCN 2023). These findings underscore the urgent need for targeted
conservation efforts to safeguard freshwater biodiversity.
The Shannon Index, Simpson Index, and
Jacquard’s Evenness Index are commonly used to measure biodiversity and
community structure in ecological studies. Biodiversity is often astonishingly
altered or overused to define the population of a community. It is a measure of
the number of species that make up a biological community and is considered one
of the most important aspects of community organization or structure (Jewel et
al. 2018). Information about ichthyofaunal diversity is scarce in this region
and only a few notable works have been done by Hora (1936), Menon (1954), Acharjee et al. (2012), and a few studies have been done on
the biodiversity status in Dikhu River individually
by Ezung et al. (2022) and Konyak
& Limatemjen (2022). The use of these diversity
indices would allow researchers to assess the species richness, evenness, and
dominance of fish populations in the Dikhu River. By
quantifying the diversity indices, researchers can determine the overall health
and stability of the fish community in the river. Understanding the fish
diversity in the Dikhu River is crucial for several
reasons. Firstly, it aids in the conservation and management of fish
populations. This information helps in formulating policies for sustainable
fisheries management. Though it is considered a significant river in the state,
there has been scarce information regarding its status and its habitat ecology
and hence this present study is an attempt to identify the current fish species
diversity in this river.
MATERIALS AND METHOD
Study area
Dikhu River is one of the tributaries of the Brahmaputra River and six
stations were selected for sampling (Table 1). The study was conducted for a
period of 12 months from March 2019 to February 2020. The locations of the
study sites were taken using GPS (Garmin etrex-10) (Image 1). It originates
from the Naruto Hill, Zunheboto, and later
confluences towards the Brahmaputra River from Naginimora,
Assam. It then channels through most of the Zunheboto
and Mokokchung districts of Nagaland, covering a
total distance of 170 km. The two major tributaries of the Dikhu
River are Yangyu in Tuensang
district and Nanung (Langpangkong
range) in Mokokchung district (Ao
et al. 2008).
Fish sampling
Fish samples were collected from various
sampling sites along the course of the river with gears such as cast nets, gill
nets, scoop nets, hooks and lines, and locally available indigenous traps.
Sampling collection was done on a monthly basis. Collected fish samples were
photographed with a Canon EOS 3000D camera and measured using a vernier caliper and graduated
ruler (graduations in mm) while excess fishes were released back into the river
then a few samples were preserved in 10% formalin solution for further
identification. Samples were identified with the help of key identification
characters given by Talwar & Jhingran (1991),
Menon (1999), Vishwanath et al. (2007), and Jayaram (2010), and the latest
nomenclature was based in accordance with the Catalog
of Fishes (Fricke et al. 2025). Fish classification was conducted following the
guidelines outlined by Nelson et al. (2016).
Species diversity
Shannon diversity index, (Shannon &
Weaver 1949)
H’ = - Σ pi ln (pi),
Where H’ is the Shannon Diversity Index and
pi is the number of individuals in the ith
species as a proportion of the total population. ln (pi) is the natural log of
pi
The formula used for calculating Simpson’s
index (Simpson 1949) is:
D = 1- (Σ n*(n-1)/N*(N-1))
Where n is the number of individuals of a
specific species. N is the total number of individuals of all species.
Pielou’s Evenness Index (J) is calculated using the Shannon Diversity Index (H)
and ln(S) is the natural logarithm of the total number of species (S) in the
community. The formula for Pielou’s Evenness Index (Pielou 1966) is:
J’ = H’/H’max = H’
/ ln(S)
The relative abundance (percentage
composition) of fish species across the six sampling stations was calculated using
the following formula.
Relative Abundance (%) = (Number of
individuals of a species × 100) / Total number of species
Statistical analysis: For data
conversion and analysis, Microsoft Excel was used.
RESULTS
Fish assemblage
Fish species composition of Dikhu River showed the presence of 28 fish species
belonging to six orders 13 families and three subfamilies (Images 2 & 3).
Table 2 provides a detailed checklist of fish species, organized according to
their IUCN conservation status (IUCN 2024) and documented population trends.
Among the order of fish species, Cypriniformes were
observed as the most dominant group with 67.9% followed by Siluriformes
(14.3%) and Anabantiformes (7.1%) while the least
common order group belonged to Beloniformes, Synbranchiformes, and Anguilliformes with combined (10.7%)
in total (Figure 1). Cyprinidae dominated among the
families represented by 14 species and among the genus group Garra, Opsarius,
and Danio were the most common with three species each. Based on the
IUCN red list of threatened species category 71.4% was represented under Least
Concern (LC), 7.1% under Near Threatened (NT), 3.6% under Vulnerable (VU), 3.6%
under Endangered (EN), 10.7% under Not Assessed (NA) and 3.6% under Data Deficient
(DD) status (Figure 2). The population trend of fish species as per IUCN also
showed 57.1% as unknown, 10.7% as stable, 10.7% as not accessed, and 21.4% as
decreasing population trends (Figure 3). Assessing the species according to its
economic value were categorized as 46.4% under food and ornamental, 35.7% under
ornamental, 10.7% under food, and 7.1% under food and sport category (Figure
4).
Relative abundance
The relative abundance of small indigenous
fish Devario aequipinnatus
(15.55%), Opsarius bendelisis
(11.39%), Garra naganensis
(9.52%), and Amblyceps apangi (7.73%)
were found to be high in the river under study indicating its abundance and
dominance. Species under different conservation categories like Neolissochilus hexagonolepis
(NT) showed relatively high RA with values of 4.31%, which indicates the
stability of their population despite natural and anthropogenic threats in the
sampling sites. While others under the threatened category like Tor putitora (EN), Anguilla bengalensis
(NT), and Botia rostrata (VU)
indicated decreasing trends with RA values of 0.62%, 0.16%, and 0.08 %. Other
species with fairly high RA were Schistura savona (6.61%), Psilorhynchus
homaloptera (5.91%), Pterocryptis
indica (5.71%) and Pethia
conchonius (5.25%). The lowest RA was recorded in
Tariqilabeo latius
and Botia rostrata with
values of 0.08% each. It has been observed that the highest number of catches
was recorded during the post-monsoon followed by the pre-monsoon season
compared to the other seasons (Figure 5).
Diversity index
Diversity was highest (H’ = 2.912, 1-D =
0.936) in post-monsoon season and lowest in monsoon season (H’ = 2.497, 1-D =
0.892), and the values of evenness index (J’) were recorded highest (J’ =
0.908) in pre-monsoon season and lowest in monsoon season (J’ = 0.82). The mean
value and standard deviation of species found in each season, Shannon diversity
(H’), Simpson’s index (1-D), and Pielou’s evenness
(J’) indices were recorded as, 23.75 ± 2.217, 2.716± 0.194, 0.915± 0.022 and
0.864± 0.044 (Table 3). The study concluded that the Dikhu
River supports rich fish diversity, while there is a notable shift in the fish
community structure.
DISCUSSION
The spatial distribution of fish species in
the Dikhu River is influenced by a complex interplay
of ecological factors, including abiotic conditions, biotic interactions, and
evolutionary adaptations within the habitat (Pelicice
et al. 2015; Bose et al. 2019; Satpathy et al. 2021; Alam et al. 2024). Among these factors, the dominance of Cypriniformes in the fish assemblages of the river is
particularly notable. This pattern mirrors findings from other studies across northeastern Indian rivers, indicating a widespread
dominance of this order (Taro et al. 2022; Ahmed et al. 2023; Chetry et al. 2023; Singh et al. 2024). The success of Cypriniformes in these ecosystems can be attributed to
their evolutionary adaptations, including the ability to thrive in a range of
water conditions, their varied feeding strategies, and reproductive behaviors, which have enabled them to outcompete other
species in these freshwater habitats. Furthermore, their efficient use of
resources has positioned Cypriniformes as central
components of the ecological dynamics in these rivers (Mondal & Bhat 2020).
Similar patterns of Cypriniformes dominance have been
reported in studies conducted in Nagaland, with most species classified by the
IUCN as either ‘Least Concern’ or ‘Data Deficient’ (Tsurunla
et al. 2024), emphasizing the need for more focused studies on the region’s
ichthyofauna. The present study also identified a significant proportion
(21.4%) of species experiencing a declining population trend, which is likely
attributable to a combination of natural environmental pressures and
anthropogenic influences (Nel et al. 2009; Kechu et al. 2021).
Relative abundance (RA) is an important
metric in ichthyological studies as it reflects the proportional representation
of species within a community. This measure is crucial for understanding
species dominance, interspecies competition, and the overall health and
stability of aquatic ecosystems (Hubbell 2005). In this study, Devario aequipinnatus
and Opsarius bendelisis
were found to have the highest RA, with values similar to those reported by
Valentina et al. (2015) in Karbi Anglong
district, Assam. Additionally, the post-monsoon season was marked by the
highest number of catches, consistent with findings by Ali et al. (2004), who
observed that receding water levels during this period tend to concentrate fish
in shallower areas, thereby increasing catch rates.
The Shannon Diversity Index is a key tool for
assessing the health of aquatic ecosystems. Values below 1 generally indicate
high pollution and stress, values between 1 and 2 suggest moderate stability
and values above 3 reflect a healthy, stable environment conducive to species
survival (Stub et al. 1970). The findings from this study align with those of Dey & Sarma (2018), who
reported the highest fish diversity during the post-monsoon season in the Manas River. Similarly, Satpathy et
al. (2021) recorded a Shannon diversity value of 2.76 for the Subansiri River, suggesting moderate ecosystem health.
Simpson’s dominance index, which emphasizes the abundance of species over
richness, also contributes to understanding the evenness of fish communities
(Islam & Yasmin 2018). In this study, the highest evenness (J’) was
recorded during the pre-monsoon season, while the lowest value occurred during
the monsoon. The average evenness across all seasons was 0.864 ± 0.044,
indicating a fairly balanced distribution of species. The post-monsoon season
consistently displayed the highest species richness and diversity, likely due
to the influx of water from various sources, which brings additional species
into the river system and enhances community diversity. Additionally, there is
a rise in species richness due to the migration of fish from larger rivers for
breeding and spawning. These seasonal dynamics underscore the critical role of
water-level fluctuations in shaping fish community composition, with the
post-monsoon period supporting the highest levels of biodiversity across the
study area.
During field surveys, interviews with local
villagers revealed a noticeable decline in fish diversity, primarily attributed
to the use of destructive fishing practices. The increasing availability and
affordability of such tools have exacerbated the problem, leading not only to a
reduction in fish populations but also negatively affecting the reproductive
success of species, thereby causing long-term ecological harm. These
observations are consistent with research suggesting that anthropogenic
activities, such as overfishing and the use of harmful fishing techniques, are
major contributors to fish population declines in river systems across Nagaland
(Kechu et al. 2021).
The lack of comprehensive taxonomic surveys,
genetic studies, and an understanding of the impacts of environmental changes
poses significant challenges to the conservation of freshwater species in northeastern India. These gaps hinder accurate species
identification and impede effective conservation planning, particularly for
rare or endemic species. Integrating traditional ecological knowledge from
local communities can provide valuable insights into fish migration patterns,
breeding cycles, and habitat usage, complementing modern scientific research
and enhancing conservation efforts (Albuquerque et al. 2021). There is an
urgent need for more holistic and integrated conservation strategies, including
habitat restoration, the promotion of sustainable fishing practices, and
community-based conservation programs. Regular ecological monitoring and
biodiversity assessments are crucial for safeguarding the aquatic ecosystems of
the Dikhu River and for meeting both local and global
biodiversity conservation goals.
Table 1.
Sampling sites of Dikhu River, Nagaland.
|
Stations |
Geographical
coordinates |
Altitude |
|
Longsa (MKG) |
26.244° N 94.517° E |
2230 ft or 679.7 m |
|
Longkong (MKG) |
26.380° N 94.662° E |
1390 ft or 423 m |
|
Chakba (MKG) |
26.403° N 94.690° E |
1292 ft or 393.8 m |
|
Alaphumi (Zunheboto) |
26.219° N 94.497° E |
2383 ft or 726.3 m |
|
Salulamang (MKG) |
26.452° N 94.704° E |
1164 ft or 354.7 m |
|
SumiSetsü (Zunheboto) |
26.234° N 94.508° E |
2271 ft or 692.2 m |
Table 2.
Comprehensive overview of fish catch composition of Dikhu River, Nagaland: conservation status, population
trends, and economic significance.
|
|
Systematic
position |
Local name (Ao) |
Common name |
IUCN status |
Population trends |
Economic value |
Specimen number |
|
Order:
Anguilliformes Family: Anguillidae |
|||||||
|
1 |
Anguilla bengalensis (Gray, 1831) |
Angulang |
Indian Mottled Eel |
NT |
Unknown |
Fd |
NUFM 1390 |
|
Order: Cypriniformes Family: Cyprinidae Subfamily: Barbinae |
|||||||
|
2 |
Neolissochilus hexagonolepis (McClelland, 1839) |
Seben |
Katli or Chocolate
mahseer |
NT |
Decreasing |
Fd, Sp |
NUFM 1279 |
|
3 |
Tor putitora (Hamilton, 1822) |
Tzünger |
Golden mahseer |
EN |
Decreasing |
Fd, Sp |
NUFM 1285 |
|
4 |
Pethia conchonius (Hamilton, 1822) |
Tzünger |
Rosy barb |
LC |
Unknown |
Fd, Or |
NUFM 1289 |
|
Subfamily: Danioninae |
|||||||
|
5 |
Opsarius bendelisis (Hamilton, 1807) |
Tawa |
Indian hill trout |
LC |
Stable |
Fd, Or |
NUFM 1310 |
|
6 |
Opsarius tileo (Hamilton, 1822) |
Tawa |
Tileo baril |
LC |
Unknown |
Fd, Or |
NUFM 1316 |
|
7 |
Opsarius barna (Hamilton, 1822) |
Tawa |
Barna Baril |
LC |
Stable |
Fd, Or |
NUFM 1317 |
|
8 |
Danio dangila (Hamilton, 1822) |
Zer |
Dangila Danio |
LC |
Decreasing |
Fd, Or |
NUFM 1325 |
|
9 |
Danio rerio (Hamilton, 1822) |
Zer |
Zebra fish |
LC |
Decreasing |
Fd, Or |
NUFM 1329 |
|
10 |
Danio assamila (Kullander,
2015) |
Zer |
Not accessed |
Not accessed |
Not accessed |
Fd, Or |
NUFM 1332 |
|
11 |
Devario aequipinnatus (McClelland, 1839) |
Zer |
Giant danio |
LC |
Unknown |
Fd, Or |
NUFM 1319 |
|
Subfamily: Labeoninae |
|
|
|
|
|
|
|
|
12 |
Tariqilabeo latius (Hamilton, 1822) |
Anget |
GangeticLatia |
LC |
Unknown |
Fd |
NUFM 1295 |
|
13 |
Garra lissorhynchus (McClelland, 1842) |
Anget |
Khasi garra |
LC |
Unknown |
Fd, Or |
NUFM 1296 |
|
14 |
Garra birostris (Nebeshwar &
Vishwanath, 2013) |
Anget |
Not accessed |
Not accessed |
Not accessed |
Fd, Or |
NUFM 1302 |
|
15 |
Garra naganensis (Hora, 1921) |
Anget |
Naga garra |
LC |
Unknown |
Fd, Or |
NUFM 1304 |
|
Family: Psilorhynchidae |
|
|
|
|
|
|
|
|
16 |
Psilorhynchus homaloptera (Hora & Mukherji, 1935) |
Mernngo |
Homaloptera minnow |
LC |
Unknown |
Or |
NUFM 1347 |
|
17 |
Psilorhynchus arunachalensis (Nebeshwar, Bagra & Das,
2007) |
Mernngo |
Not accessed |
DD |
Unknown |
Or |
NUFM 1353 |
|
Family: Botiidae |
|
|
|
|
|
|
|
|
18 |
Botia rostrata (Günther, 1868) |
Nga-medaktsü |
Gangetic loach |
VU |
Decreasing |
Or |
NUFM 1356 |
|
Family: Nemacheilidae |
|
|
|
|
|
|
|
|
19 |
Paracanthocobitis botia (Hamilton, 1822) |
Sangsert |
Mottled loach |
LC |
Decreasing |
Or |
NUFM 1335 |
|
20 |
Schistura savona (Hamilton, 1822) |
Retong |
Half-banded Loach |
LC |
Unknown |
Or |
NUFM 1341 |
|
Order: Siluriformes Family: Siluridae |
|||||||
|
21 |
Pterocryptis indica (Datta, Barman &
Jayaram, 1987) |
Lorng |
Siluras Catfish |
DD |
Unknown |
Fd |
NUFM 1360 |
|
Family: Bagridae |
|
|
|
|
|
|
|
|
22 |
Olyra longicaudata (McClelland, 1842) |
Nenak |
Torrent Catfish |
LC |
Unknown |
Or |
NUFM 1357 |
|
Family: Amblycipitidae |
|
|
|
|
|
|
|
|
23 |
Amblyceps apangi (Nath & Dey,
1989) |
Nenak |
Indian Torrent
Catfish |
LC |
Unknown |
Or |
NUFM 1368 |
|
Family: Sisoridae |
|
|
|
|
|
|
|
|
24 |
Glyptothorax indicus (Talwar,
1991) |
Jangmu |
Catfish |
LC |
Unknown |
Or |
NUFM 1366 |
|
Order: Anabantiformes Family: Channidae |
|||||||
|
25 |
Channa melanostigma (Geetakumari
& Vishwanath, 2011) |
Alopungo |
snakehead |
Not accessed |
Not accessed |
Fd, Or |
NUFM 1374 |
|
Family: Badidae |
|||||||
|
26 |
Badis badis (Hamilton, 1822) |
Akngo |
Badis |
LC |
Unknown |
Or |
NUFM 1379 |
|
Order: Beloniformes Family: Belonidae |
|||||||
|
27 |
Xenentodon cancila (Hamilton, 1822) |
Jokli |
Freshwater Garfish |
LC |
Unknown |
Or |
NUFM 1385 |
|
Order: Synbranchiformes Family: Mastacembelidae |
|
|
|
|
|
|
|
|
28 |
Mastacembelus armatus (Lacepède,
1800) |
Merü |
Spiny Eel |
LC |
Stable |
Fd, Or |
NUFM 1388 |
DD—Data Deficient |
EN—Endangered | LC—Least Concern | NT—Near Threatened | VU—Vulnerable | Fd—Food | Sp—Sport |
Or—Ornamental.
For
figures & images - - click here for full PDF
REFERENCES
Acharjee, B.K., M. Das, P. Borah & J. Purakayastha (2012). Ichthyofaunal diversity of Dhansiri River, Dimapur, Nagaland, India. Check List 8(6):
1163–1165.
Ahmed, A.M., R. Dutta, H. Pokhrel,
D. Nath, L. Mudoi, R. Sarmah,
S.K. Bhagabati & I. Ahmed (2023). Fish species composition, distribution, and
community structure of a Himalayan biodiversity hotspot river Diyung, north east India. Pakistan Journal of Zoology
1–11.
Alam, A., J. Kumar, U.K. Sarkar, D.N. Jha, S.K. Sahu, S.C. Sukla Das, S.K.
Srivastava, S.K., V. Kumar & B.K. Das (2024). Linking ecological characteristics with fish
diversity, assemblage patterns and feeding guilds, and GIS applications along
the temporal and spatial gradients in a large subtropical reservoir, India, for
sustainable management. Journal of Water and Climate Change 15(2):
607–627.
Albuquerque, U., D. Ludwig, I. Feitosa, J. De Moura, P. Gonçalves, R. Da Silva, T. Da
Silva, T. Gonçalves-Souza & W. Júnior (2021). Integrating traditional ecological knowledge
into academic research at local and global scales. Regional Environmental
Change 21: 45. https://doi.org/10.1007/s10113-021-01774-2
Ali, M.Y., G.M. Salim, M.A. Mannan, M.M.
Rahman, W. Sabbir & A. Murshida
(2004). Freshwater fish fauna of
Mymensingh floodplain, Bangladesh. Journal of Biological Sciences 4(5):
575–580.
Ao, S., S.C. Dey
& S.K. Sarmah (2008). Fish and fisheries of Nagaland. Inland
Fisheries Society of India 26: 1–19.
Bose, R., A.K. Bose, A.K. Das, A. Parashar
& K. Roy (2019). Fish
diversity and limnological parameters influencing fish assemblage pattern in
Chambal River Basin of Madhya Pradesh, India. Proceedings of the National
Academy of Sciences, India Section B: Biological Sciences 89: 461–473. https://doi.org/10.1007/s40011-017-0958-5
Chetry, V., H. Das, P.K. Saikia,
M.K. Saikia, B.P. Saikia
& K. Sarma (2023). Ichthyofaunal diversity in Jia Bharali River of North Bank Landscape of Assam in eastern
Himalaya, northeast India. Ecology, Environment and Conservation 29(01):
145–157.
Dey, A. & D. Sarma
(2018). Diversity, distribution
and conservational approach of hillstream ornamental
fishes in Manas River, India: An eastern hotspot
region. Journal of Coldwater Fisheries 1(1): 103–112.
Ezung, S., M. Kechu
& P.P. Pankaj (2022). First
record of Garra birostris
Nebeshwar & Vishwanath, 2013 (Cypriniformes:
Cyprinidae) from Doyang and
Dikhu rivers of Brahmaputra drainage, Nagaland,
India. Journal of Threatened Taxa 14(7): 21453–21457. https://doi.org/10.11609/jott.7075.14.7.21453-21457
Fricke, R., W.N. Eschmeyer
& R. Van Der Laan (eds.) (2025). Eschmeyer’s
Catalog of Fishes: Genera, Species, References.
Electronic version accessed 23 January 2025. http://researcharchive.calacademy.org/research/ichthyology/catalog/fishcatmain.asp
Groombridge, B. & M. Jenkins (1998). Freshwater Biodiversity: A Preliminary
Global Assessment. World Conservation Monitoring Centre, Cambridge, U.K.,
104 pp.
Hora, S.L. (1936). Fish and fisheries of Manipur with some observations
on those of the Naga Hills. Records of the Indian Museum (Calcutta) 22:
165–214. https://doi.org/10.1016/0022-5193(66)90133-0
Hubbell, S.P. (2005). The neutral theory of biodiversity and
biogeography and Stephen Jay Gould. Paleobiology 31(2): 122–132.
Islam, M. & R. Yasmin (2018). Assemblage, abundance and diversity of fish
species in river Dhaleshwari, Bangladesh. Asian
Journal of Fisheries and Aquatic Research 1: 1–28. https://doi.org/10.9734/ajfar/2018/v2i126112
IUCN (2023). Freshwater fish highlight escalating climate
impacts on species: IUCN Red List. Available at:
https://iucn.org/press-release/202312/freshwater-fish-highlight-escalating-climate-impacts-species-iucn-red-list?utm_source
(Accessed: 22 January 2025).
IUCN (2024). The IUCN Red List of Threatened Species.
Version 2024-2. https://www.iucnredlist.org Accessed on 23 January 2025.
Jayaram, K.C. (2010). Freshwater Fishes of Indian Region. 2nd
Edition. Narendra Publishing House, New Delhi, 616 pp.
Jewel, M.A.S., M.A. Haque,
R. Khatun & M.S. Rahman (2018). A comparative study of fish assemblage and diversity indices in two
different aquatic habitats in Bangladesh: Lakhandaha
Wetland and Atari River. Jordan Journal of Biological Sciences 11(4):
427–434.
Kechu, M., S. Ezung, S. Longkumer, A. Jamir & P.P. Pankaj (2021). Progress and prospects for sustainable
production and conservation of threatened coldwater
fishes of north-east India with special reference to Nagaland state. Journal
of Experimental Zoology India 24(1): 27–33.
Konyak, S.L. & Limatemjen
(2022). Ichthyofaunal diversity
of downstream Dikhu River and its tributaries in Mon
District of Nagaland, India. Asian Journal of Fisheries and Aquatic Research
18(1): 16–22. https://doi.org/10.9734/ajfar/2022/v18i130427
Kosygin, L. & W. Vishwanath (1998). A report on fish diversity of Tizu River, Nagaland with some new records. Ecology,
Environment and Conservation 4: 243–247.
Kottelat, M. & T. Whitten (1996). Freshwater Biodiversity in Asia with
Special Reference to Fish: World Bank Technical Paper No. 343. The World
Bank, Washington DC, 59 pp.
Kottelat, M. (1989). Zoogeography of the fishes from Indochinese
inland waters with an annotated check-list. Bulletin Zoologisch
Museum 12(1): 1–55.
Menon, A.G.K. (1954). Further observation on the fish fauna of the
Manipur State. Records of the Indian Museum 52: 21–26.
Menon, A.G.K. (1999). Checklist: Freshwater Fishes of India.
Occasional Paper No. 175. Zoological Survey of India, Calcutta, 366 pp.
Mittermeier, R.A. & C.G. Mitemeir (1997). Megadiversity: earth’s biologically wealthiest nations. In: McAllister,
M.C., D.E. Hamilton & B. Harvey (eds.). Global Freshwater Biodiversity.
Sea Wind Cemex, Mexico City, 140 pp.
Mondal, R. & A. Bhat (2020). Temporal and environmental drivers of
fish-community structure in tropical streams from two contrasting regions in
India. PLOS ONE 15(4): e0227354. https://doi.org/10.1371/journal.pone.0227354
Nel, J.L., D.J. Roux, R. Abell, P.J. Ashton,
R.M. Cowling, J.V. Higgins & J.H. Viers (2009). Progress and challenges in freshwater
conservation planning. Aquatic Conservation: Marine and Freshwater
Ecosystems 19(4): 474–485.
Nelson, J.S., T.C. Grande & M.V.H. Wilson
(2016). Fishes of the World.
5th Edition. John Wiley & Sons, Hoboken, 707 pp. https://doi.org/10.1002/9781119174844
Pelicice, F.M., P.S. Pompeu
& A.A. Agostinho (2015). Large reservoirs as ecological barriers to downstream movements of
Neotropical migratory fish. Fish and Fisheries 16(4): 697–715. https://doi.org/10.1111/faf.12089
Pielou, E.C. (1966). Species-diversity and pattern-diversity in
the study of ecological succession. Journal of Theoretical Biology
10(2): 370–383.
Satpathy, S., K. Sivakumar & J.A. Johnson (2021). Fish communities and associated habitat
variables in the upper Subansiri River of Arunachal
Pradesh, eastern Himalaya, India. Journal of Threatened Taxa 13(1):
17477–17486. https://doi.org/10.11609/jott.5503.13.1.17477-17486
Sayer, C.A., E. Fernando & R.R. Jimenez
(2025). One-quarter of freshwater
fauna threatened with extinction. Nature 1–8. https://doi.org/10.1038/s41586-024-08375-z
Shannon, C.E. & W. Weaver (1949). The Mathematical Theory of Communication.
The University of Illinois Press, Urbana, IL, 1–117.
Simpson, E.H. (1949). Measurement of diversity. Nature 163:
688. https://doi.org/10.1038/163688a0
Singh, D., J. Rana & J. Tungoe (2024). Impact of prevailing factors on assemblages and status of freshwater
fish fauna of river Song in the ower Himalaya. Iranian
Journal of Fisheries Sciences 23(2): 237–254. https://doi.org/10.22092/ijfs.2024.349403.0
Stub, R., J.W. Appling, A.M. Hatstetter & I.J. Hass (1970). The effect of industrial waste of Memphis
and Shelby country on primary planktonic producers. Bioscience 20:
905–912.
Talwar, P.K. & A.G. Jhingran
(1991). Inland Fishes of India
and Adjacent Countries, Vols. I & II. Oxford and IBH Co. Pvt. Ltd., New Delhi, 1158 pp.
Taro, K., L. Tamang & D.N. Das (2022). Ichthyofaunal diversity of Senkhi stream, Itanagar,
Arunachal Pradesh: a comparative status between 2004–05 and 2018–19. Journal
of Threatened Taxa 14(7): 21356–21367. https://doi.org/10.11609/jott.5738.14.7.21356–21367
Tsurunla, K., L. Limatemjen,
S.L. Konyak, & V. Chüzho
(2024). Fish fauna and their IUCN
conservation status of Chessore sub-division of Shamator, Nagaland, India. World News of Natural
Sciences 56: 58–66.
Valentina, T., H.T. Singh, A. Tamuli & R. Teron (2015). Assessment of physico-chemical
characteristics and fish diversity of hill streams in Karbi
Anglong District, Assam, India. International
Research Journal of Environmental Sciences 4(5): 6–11.
Vishwanath, W. (2017). Diversity and conservation status of
freshwater fishes of the major rivers of northeast India. Aquatic Ecosystem
Health & Management 20(1–2): 86–101. https://doi.org/10.1080/14634988.2017.1294947
Vishwanath, W., W.S. Lakra & U.K. Sarkar
(2007). Fishes of North East
India. NBFGR, Lucknow, Uttar Pradesh, India, 264 pp.