Journal of Threatened Taxa |
www.threatenedtaxa.org | 26 June 2021 | 13(7): 18899–18902
ISSN 0974-7907 (Online) | ISSN 0974-7893
(Print)
https://doi.org/10.11609/jott.4413.13.7.18899-18902
#4413 | Received 21 July 2020 | Final
received 25 August 2020 | Finally accepted 16 June 2021
First report on the occurrence of
Sargassum Weed Fish Histrio
histrio (Lophiliformes:
Antennariidae) in Nigeria deep water, Gulf of Guinea
Abdul-Rahman Dirisu
1, Hanson S. Uyi 2 & Meshack Uyi 3
1 Department of Animal And
Environmental Biology, Faculty of Life Sciences, University of Benin, Benin
City, Edo State, P.M.B 1154, Nigeria.
2,3 Institute of Pollution Studies,
Rivers State University, Nkpolu, Port Harcourt,
Rivers State, P.M.B. 5080, Nigeria.
1 dedonrahman10@yahoo.com
(corresponding author), 2 hansonuyi@gmail.com, 3 uyimeshack@gmail.com
Editor: A. Biju Kumar, University of
Kerala, Thiruvananthapuram, India. Date of
publication: 26 June 2021 (online & print)
Citation: Dirisu,
A.R., H.S. Uyi & M. Uyi
(2021). First report on the occurrence of
Sargassum Weed Fish Histrio
histrio (Lophiliformes:
Antennariidae) in Nigeria deep water, Gulf of Guinea.
Journal of Threatened Taxa 13(7): 18899–18902. https://doi.org/10.11609/jott.4413.13.7.18899-18902
Copyright: © Dirisu
et al. 2021. 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: Funding was provided
by SNEPCo in 2014 for an environmental
study.
Competing interests: The authors
declare no competing interests.
Acknowledgements: Thanks to Technology Partners
International (TPI) in Lagos, for selecting us to be part of the environmental
study for SNEPCo which led to this piece of work. We
are also very thankful to the entire crew members of M/V African Vision for the
enabling environment they created while we were onboard. We gratefully
acknowledge the anonymous reviewers for their critique, which greatly improved
the paper.
Abstract: We report the first occurrence of
Sargassum Weed Fish Histrio
histrio at Bonga Field in Nigeria Outer
Continental Shelf approximately 120 km south-east of Delta State in February
2014. At high tides and under difficulty, we sampled some seaweeds in the
epi-pelagic realm using a secured standard plankton net to the environmental
research vessel that was cruising at a dead speed (≤4 knots). Upon examination
of the weeds we collected, one adult Sargassum Weed
Fish along with two gelatinous fingerlings were realised. This finding suggests
the probable occurrence of more population of Sargassum
Weed Fish in their macro-habitat (the Sargassum
seaweeds) which are abundantly bound in the Gulf of Guinea deep waters. The
specimen was photographed on-board and preserved immediately in 10 % formalin
solution for a 24-h period and was thereafter reprocessed, and permanently
preserved with 70 % ethanol. We recommend a major study of the marine seaweeds
and their colonisers amongst Gulf of Guinea member states.
Keywords: Bonga Field, Frogfish, Nigeria
Offshore, Pelagic Zone, Seaweed.
Sargassum weeds are bound in abundance in
the Gulf of Guinea (GoG) stretch but have not been
examined as habitats and niches for several marine organisms, as evident from
the lack of publications. These weeds are essential habitats to lots of pelagic
dwelling organisms, for example; plankton, parasitic forms, and fishes
(Kingsford 1992; Wells & Rooker 2004; Rogers et
al. 2010; Rampersad 2016).
The identification and
conservation of essential fish habitat was advocated as prerequisite to
building healthy and sustainable fisheries (Rosenberg et al. 2000). Till date,
considerable works have been focused upon characterising the spatial and
temporal patterns of habitat use by fishes (Lindeman et al. 2000; Wells & Rooker 2004), and these efforts have led to valuable
information regarding the physical attributes and biological significance of
these habitats. Unfortunately, information on habitat use of pelagic species
are limited and one of such studies was carried out in the western Atlantic
(Wells & Rooker 2004). The pelagic zone is
typically characterised by its lack of physical structure and previous studies
suggest that many pelagic organisms associate with structures such as the algal
mats or seaweeds, particularly during early life stages (Dooley 1972; Rountree
1990; Kingsford 1992; Wells & Rooker 2004).
This paper seeks to document the
first occurrence of the Sargassum Weed Fish Histrio histrio in
Nigeria deep water. We therefore, use this medium to welcome collaborative work
on this subject in future.
Materials and Method
The Study Area
The Bonga oil field is located in
Oil Mining License (OML) 118 (4035’47”N, 4037’27”E),
Offshore-Nigeria, with the license area lying about 120 km off the Nigeria
coastline (Figure 1). The water depth of the block range from 1,000 m to 1,150
m and the Bonga field is located in approximately 1,030 m of water. The field
was discovered in 1995 and began first production in November 2005.
The field is characterised by
heavy precipitation and high solar radiation. The North and South Atlantic
subtropical highs and equatorial low-pressure system control its climate. Rainy
season is between February and November, while dry season is between December
and January. During the dry season, there may be haze and thick fog at dawn due
to the dust carried by the prevailing Harmattan winds. The dominant waves are large swell waves
generated by the prevailing south-south west winds offshore Nigeria. A
secondary set of short wavelength waves generated by episodic surges in the
southeast winds just off the Namibian coast manifest in the Bonga field area
from 214º direction. The two dominant wind systems are the South West Trade
Wind (or Tropical Marine Air Mass) and North East Trade Wind (or Tropical
Continental Air Mass). The South West Trade Wind originates from the Southern
Hemisphere around St. Helens from where it initially moves as the South
Easterly Wind and then veers eastwards to become the South Westerly Wind as it
crosses the equator (SNEPCo 2014).
Sampling
We sampled for aquatic weed (Sargassum seaweed) in February 2014 while conducting a
major environmental study. A 55-micron mesh size plankton net was lowered onto
the sea onboard an environmental vessel while cruising at a low speed of 4
knots amidst high tide. The sampler held the net against the direction of the
water current (the bow heading) while securing himself with harness by the
portside. The collected weeds were introduced into a small bowl and examined.
Our interest was to preserve the weeds for a museum, fortunately we harvested
an adult Sargassum weed fish which was immediately
preserved in 10 % formalin solution for 24 h. It was there after removed and
washed in sea water, and again introduced into 70 % ethanol for further
studies. The specimen was identified online onboard at various websites.
Specimen was photographed freshly onboard. We also recorded pH, total dissolved
solids, electrical conductivity, turbidity and salinity using HANNA probe and turbidometer for in situ studies. While temperature was
measured using mercury in glass thermometer calibrated from 0–100 0C
(Krisson model-59). Every other parameters were
measured by dipping the calibrated HANNA probe and turbidometer
into the sampled sea water immediately after collection, and the corresponding
values read from the digital display on the screens were recorded.
Results and Discussion
The environmental variables
(Table 1) such as water temperature, pH, total dissolved solids, dissolved
oxygen, electrical conductivity, turbidity and salinity had their values within
tropical seas condition (EGASPIN 2002).
The classification of the
specimen Histrio histrio
and the common name in parenthesis is given thus (Rampersad
2016):
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterigii
(Ray-finned Fish)
Order: Lophiliformes
(Anglerfish and Frogfish)
Family: Antennariidae
(Frogfish)
Genus: Histrio
G. Fischer, 1813
H. histrio
Linnaeus, 1758 (Sargassum Weed Fish)
The fish was harvested from Sargassum seaweed Sargassum
fluitans which also harboured a rich community of
plankton. The nature and the occurrence of the Sargassum
Weed Fish is in consistency with previous reports (Wells & Rooker 2004; Rogers et al. 2010). The colonization of Sargassum mat by pelagic fishes of which H. histrio may not have been an exception was reported by
Wells & Rooker (2004) from the Gulf of Mexico and
Bray & Thompson (2020) from Australia.
The Sargassum
Weed Fish is also known as Frogfish. Amongst its other names across the world
are: Marbled Angler, Mouse Fish, Sargassum
Anglerfish, Sargassum Frogfish, Sargassumfish,
and Sargassum-fish (Bray & Thompson 2020). It is
the only pelagic member of the frogfish family Antennariidae,
which is considered an obligate associate of floating mats of the brown algae Sargassum natans
and S. fluitans (Adams 1960; Dooley 1972;
Pietsch & Grobecker 1987; Wells & Rooker 2004; Rogers et al. 2010). Only one adult form and
two gelatinous fingerlings were harvested from the weed colonies. Before now,
there was no report on the occurrence of this fish in the Gulf of Guinea.
A detailed description of its
reproduction, habitats and biology was published earlier (Rogers et al. 2010; McEachran et al. 2015; Rampersad
2016) based on the study from the USA, Trinidad & Tobago, the Pacific, and
Nigeria most recently. The specimens (Image 1) are in conformity to the body
size, colourations and habitat types by the works of the aforementioned
authors. The standard measurement (i.e., total length, TL) of the adult
specimen from Bonga field, offshore Nigeria in the Gulf of Guinea was 61mm
(Image 1) but could be up to 100 mm (Rogers et al. 2010). Meanwhile, the
gelatinous juvenile forms were 0.8 and 0.9 cm, of which their pictures were not
good enough for documentation purpose due to their denaturation upon
preservation.
Its distribution cut across both
the temperate and tropical regions of the world, such as, the Caribbean Basin,
Sargasso Sea, western Pacific, and Indian Oceans (McEachran
et al. 2015) and currently in the Gulf of Guinea. Its reproduction
involves courtship between the male which closely follows the female, rushing
to the epipelagic region to spawn. Spawning is frequent and regular for more
than a two week period. They produce eggs on the surface and have an appearance
of being blunt at both ends with a slightly larger middle. After the female
releases her eggs the male externally fertilises them as it is in other fishes.
The Juveniles then move to depths exceeding 200m, where they feed and become
adults, and thereafter return to the Sargassum weeds
above. The juveniles feed on other fish eggs and small crustaceans, amphipods,
decapods, euphausids and shrimps, whereas adults feed
on other fish and shrimps among the seaweed at the surface (Rampersad
2016). On its biology, Rampersad (2016) reported
again that the sargassum fish can hold the ciguatoxin
poison, accumulated from its food, and can cause ciguatera poisoning in humans.
This could be one of the reasons while the species is of Least Concern on the
IUCN Red List (McEachran et al. 2015) and
importantly, its population thrives since it is not consumable by humans. The
habitat and ecology correspond to what we observed and documented at Bonga
field in the Gulf of Guinea. Whereby they usually find refuge in the floating Sargassum seaweed mats which can cover a depth of 0–5 m. In
these Sargassum mats, adults and eggs can be found
but, the larvae of the species usually develop in water columns between 50–600
m (McEachran et. al. 2015; Rampersad
2016).
In conclusion, we strongly
believe that there could be more to learn from Histrio
histrio if given the opportunity to carry out a
major study regarding species diversity, community structure, its seasonal
preference and occurrences in the Gulf of Guinea member states. Since, the
species is not documented in FAO book of fishes of economic importance and it
is of Least Concern on the IUCN Red List, it is therefore crucial to understand
its biology and tropical ecology as well as population in addition to existing
documentations. This will further tell whether it is threatened in this region
owing to increasing deep sea anthropogenic activities or not.
Table 1. Measured values of some
abiotic conditions/sea state in Bonga field.
Environmental variables |
Value/
state |
Water Temperature (0C) |
27.9 |
pH |
8.18 |
Total Dissolved Solids (mgL-1) |
25060 |
Dissolved Oxygen (mgL-1) |
3.29 |
Electrical Conductivity (µScm-1) |
50120 |
Turbidity (NTU) |
0.87 |
Salinity (PSU) |
32.74 |
Swell (m) |
Medium (2–4) |
Visibility (km) |
Good (>5) |
For
figure & image - - click here
References
Adams, J.A.
(1960). A
contribution to the biology and post larval development of the Sargassum fish, Histrio histrio (Linnaeus), with a discussion of the Sargassum complex. Bulletin of the Marine Science and
Gulf of Caribbeans 10: 55–82.
Bray, D.J.
& V.J. Thompson (2020). Histrio histrio
in Fishes of Australia, accessed 21 Jul 2020. https://fishesofaustralia.net.au/Home/species/3837
Dooley, J.K.
(1972). Fishes
associated with the pelagic Sargassum complex, with a
discussion of the Sargassum community. Contributions
in Marine Science 16: 1–32.
Dooley, J.K.
(1972). Fishes
associated with the pelagic Sargassum complex, with a
discussion of the Sargassum community. Contributions
in Marine Science 16: 1–32.
Environmental
Guidelines and Standards for the Petroleum Industry in Nigeria (EGASPIN)
(2002). Issued by
the Department of Petroleum Resources, Lagos.
Kingsford,
M.J. (1992). Drift algae
and small fish in coastal waters of northeastern New
Zealand. Marine Ecology Progress Series 80: 41–55.
Lindeman,
K.C., R. Pugliese, G.T. Waugh & J.S. Ault (2000). Developmental patterns within a
Multispecies reef fishery: Management applications for essential fish habitats
and protected areas. Bulletin of Marine Science 66: 929–956.
Littler, D.S.
& M.M. Littler (2000). Caribbean reef plants. Offshore Graphics Inc, Washington, DC, 542pp.
McEachran, J.D., A. F. Polanco & B.
Russell (2015). Histrio histrio.
IUCN Red List. Accessed online on 23rd of May, 2020. http://www.iucnredlist.org/details/190183/0
Pietsch, T.W.
& D.B. Grobecker (1987). Frogfishes of the World.
Stanford University Press, Stanford, CA, 420pp.
Rampersad, N. (2016). The Online Guide to the Animals
of Trinidad and Tobago. [https://www.flickr.com/photos/artour_a/3668148849,
downloaded 31 October 2016]
Rountree,
R.A. (1990). Community
structure of fishes attracted to shallow water fish aggregation devices off
South Carolina, U.S.A. Environmental Biology of Fishes 29: 241–262.
Rosenberg,
A., T. E. Bigford, S. Leathery, R. L. Hill & K.
Bickers (2000). Ecosystem
approaches to fishery management through essential fish habitat. Bulletin of
Marine Science 66: 535–542.
Rogers, C.S.,
T.W. Pietsch, R.J. Arnold & J.E. Randall (2010). The Sargassum
Frogfish (Histrio histrio
Linnaeus) observed in mangroves in St. John, US Virgin Islands. Coral Reefs
29: 577. https://doi.org/10.1007/s00338-010-0636-z
Wells, D.R.J.
& J.R. Rooker (2004). Spatial and Temporal Patterns of
Habitat Use by Fishes Associated with Sargassum Mats
in the northwestern Gulf Of Mexico. Bulletin of
Marine Science 74(1): 81–99.
SNEPCo (2014). Draft terms of Reference for the
Environmental evaluation/biological Monitoring studies of Bonga main field
(OML-118). Shell Nigeria Exploration and Production Company Limited, 29pp.
[https://www.flickr.com/photos/artour_a/3668148849,
downloaded 31 October 2016]