Studies on fish biology are important because they help determine the best management strategy to use in order to conserve fish species in their natural habitat. Thus, some aspects of the Biology of Sarotherodon melanotheron and Tilapia guineensis in the Mahin Lagoon were covered in this study. For the study, 121 fish samples were collected. The sex ratio of S. melanotheron (1:1.64) and T. guineensis (1:1.36) showed no significant deviation from the expected 1:1. Fecundity ranged from 243 to 1223 in S. melanotheron and 156 to 600 in T. guineensis with means of 344.39±166.85 and 286.27±114.85 respectively indicating low fecundity in both species. Observed Gonado-Somatic Index (6.40±3.25% for T. guineensis and 5.65±3.31% for S. melanotheron) suggested the peak of gonad maturity. The regression equation of the length-weight relationship indicated that S. melanotheron exhibited negative allometric growth in male (b=1.66, R2=0.63), female (b=2.80, R2=0.83) and combined sex (b=2.55, R2=0.78) while T. guineensis exhibited positive allometry in male (b=3.05, R2=0.97), female (b=3.04, R2=0.95) and combined sex (b=3.04, R2=0.96). The condition factor was greater than 2 for both species. This study also revealed that the fecundity of the two species was size dependent. Examination of stomach fullness revealed that 4.2% and 0.0% of S. melanotheron and T. guineensis had empty stomachs while 20.0% and 3.8% had full stomachs respectively. This study therefore established that the study area was conducive for the fish. Monitoring and regulation of the fisheries is therefore recommended for conservation and management of the study area.
Loto, O.O., Ajibare, A.O. and Abah, J.P. (2021): Gut Contents, Feeding Ecology and Condition Factor of Sarotherodon melanotheron inhabiting Lagos Lagoon, Nigeria. International Journal of Science and Global Sustainability, 7, 69‒74.
Idodo-Umeh G (2003). Fresh water fishes in Nigeria, (Taxonomy, Ecological notes, Diets and Utilization). Idodo-Umeh Publishers, Benin City. Nigeria. Pp 123‒124.
Andem AB, George UU and Eyo VO (2013). Length Frequency Distribution of Chrysichthys nigrodigitatus (Lecepede, 1803) from Itu Head Brigde, in Akwa Ibom State, Nigeria. International Journal of Scientific Research, 2, 258‒260.
Offem BO, Ayotunde EO and Ikpi GU (2008). Dynamics in the reproductive biology of Heterobranchus longifilis Val., (Pisces: 1840) in the wetlands of Cross River, Nigeria. Research Journal of Fisheries and Hydrobiology, 3, 22‒31.
Ajibare, A.O. and Loto, O.O. (2022): Length-Weight Relationship and Condition Factor of Sarotherodon melanotheron and Tilapia guineensis in Lagos lagoon, Nigeria. Agrosearch, 21, 57‒66. https://doi.org/10.4314/agrosh.v21i1-2.5.
Olawusi-Peters O.O. and Ajibare A.O. (2014): Species Richness, Diversity and Abundance of Some Decapod Crustaceans in Coastal Waters of Ondo State, South West, Nigeria. International Journal of Fauna and Biological Studies, 1, 44‒51.
Kareem OK, Ajani EK, Orisasona O, Olanrewaju AN (2015) The Sex Ratio, Gonado-somatic Index, Diet Composition and Fecundity of African Pike, Hepsetus odoe (Bloch, 1794) in Eleyele Lake, Nigeria. Journal of Fisheries & Livestock Production, 3, 139. https://doi.org/10.4172/2332-2608.1000139.
Oso JA, Ogunleye OA, Idowu EO and Majolagbe FA (2013). Gonado-Somatic Index, Sex Ratio and Fecundity of Tilapia zilli in a Tropical Reservoir, South West Nigeria. Journal of Biology, 1, 42‒45.
Indarjo A., Salim G., Nugraeni C.D., Zein M., Ransangan J., Prakoso L.Y., Suhirwan, Anggoro S. (2021): Length-weight relationship, sex ratio, mortality and growth condition of natural stock of Macrobrachium rosenbergii from the estuarine systems of North Kalimantan, Indonesia. Biodiversitas, 22, 846‒857 http://doi.org/10.13057/biodiv/d220239.
Jega I.S., Miah M.I., Haque M.M., Shahjahan M., Ahmed Z.F. and Fatema M.K. (2017): Sex ratio, length-weight relationships and seasonal variations in condition factor of menoda catfish Hemibagrus menoda (Hamilton, 1822) of the Kangsha River in Bangladesh. International Journal of Fisheries and Aquatic Studies. 5, 49‒54.
Vicentini, RN. and Araujo, FG. (2003). Sex ratio and size structure of Micropogonias furnieri (Desmarest, 1823) (Perciformes, Sciaenidae) in Sepetiba bay, Rio de Janeiro. Brazilian Journal of Biology, 3, 559‒566. https://doi.org/10.1590/s1519-69842003000400003.
Kahn AT, Kokko H, and Jennions MD. (2013): Adaptive sex allocation in anticipation of changes in offspring mating opportunities. Nature Communnication, 4, 1603. https://doi.org/10.1038/ncomms2634.
Arendt JD, Reznick DN, Lo´pez-Sepulcre A. (2014): Replicated origin of female-biased adult sex ratio in introduced populations of the Trinidadian Guppy (Poecilia reticulata). Evolution, 68, 2343–2356. https://doi.org/10.1111/evo.12445.
Fryxell DC, Arnett HA, Apgar TM, Kinnison MT, Palkovacs EP. (2015): Sex ratio variation shapes the ecological effects of a globally introduced freshwater fish. Proceedings of the Royal Society B: Biological Sciences, 282, 20151970. http://doi.org/10.1098/rspb.2015.1970.
Ajibare, A.O. and Loto, O.O. (2023): Risks Assessment of Copper (Cu), Lead (Pb), Mercury (Hg) and Zinc (Zn): A case study of Tilapia guineensis in Lagos Lagoon. Ghana Journal of Agricultural Science, 58, 77– 84. https://doi.org/10.4314/gjas.v58i1.7.
Adesulu EA and Sydenham DHJ. (2007): The freshwater fishes and fisheries of Nigeria. Macmillan Nigeria Publishers Limited: Lagos, Nigeria.
Olaosebikan, B.D. and Raji, A. (2013). Field guide to Nigerian Freshwater Fishes. Federal College of Freshwater Fisheries Technology: New Bussa, Nigeria.
Adebiyi, FA. (2013). The sex ratio, gonadosomatic index, stages of gonadal development and fecundity of Sompatgrunt Pomadasys jubelini (Cuvier, 1830). Pakistan Journal of Zoology, 45, 41‒46.
Nzeh CG and Lawal A (2012). Condition Factor, Gonadosomatic Index and Sex Ratio of the Family Mormyridae from a Small Lake in Ilorin, Nigeria. World Journal of Zoology, 7, 102‒105
Onah (2014). Aspect of the biology of Mormyrus rume of Cross river as Ahaha. Bachelor Thesis, Cross River University of Technology, Cross River, Nigeria.
Oboh IP and Omoigberale MO (2013). Fecundity and spawning frequency of Chrysichthys furcatus Gunther, 1864 (Osteichthyes: Bagridae) from Jamieson River, Nigeria. Peak Journal of Agricultural Science, 2, 2129.
Al-Nahdi., Al-Marzouqi, A., Jayaabalan, N and Al-Habsi, S. (2010). Maturation and spotting of the small spotted grunt, Pomadasys commersonnii (lacepede, 1801) in the Arabian Sea off Oman. Thalassas, 27, 67‒79.
Rheman S, Islam ML, Shah MMR, Mondal S and Alam MJ (2002). Observation on the fecundity and gonadosomatic index (GSI) of Grey Mullet, Liza parsia (Ham.). Journal of Biological Sciences, 2, 690‒693. http://doi.org/10.3923/jbs.2002.690.693.
Olawusi-Peters O.O., Ajibare A.O. and Bello-Olusoji O.A. (2014). Length-Weight Relationship and Condition Factor of Shrimps in Coastal Waters of Ondo State, South West, Nigeria. International Journal of Fisheries and Aquatic Studies, 1, 137‒142.
Fehri-Bedoui, R and Gharbi, H. (2008). Sex ratio, reproduction and feeding habits of Pomadasys incisus (Haemulidae) in the gulf of Tunis (Tunisia). Acta Adriatica, 49, 5‒19.
Omobepade, B.P. and Ajibare, A.O. (2015): Morpho-Fecundity of Berried African River Prawn (Macrobrachium vollenhovenii) in Asejire Reservoir, Nigeria. International Journal of Fisheries and Aquatic Studies, 3, 206‒211.
SUBMITTED: 13 September 2023
ACCEPTED: 06 January 2024
PUBLISHED:
14 January 2024
SUBMITTED to ACCEPTED: 115 days
DOI:
https://doi.org/10.53623/tebt.v2i1.314