Growth patterns, diet composition and reproduction in the ten pounder, Elops lacerta from Ologe lagoon, Lagos, Nigeria

Abstract

Ten pounder, Elops lacerta, a member of the family Elopidae is a tropical and subtropical fish species. Growth patterns, food and feeding habits and reproduction of 317 specimens of E. lacerta were investigated in Ologe lagoon, Lagos, Nigeria. Diurnal and nocturnal fishing activities were carried out in the lagoon using cast and gill nets. The specimens examined ranged from 90-375mm total length (TL) and weighed 4.7-214g body weight (BW) respectively. Of the specimens 49.5% were juveniles, 36.3% fingerlings and 14.2% adults. Specimens were classified as unsex, males and females their growth exponential "b" values were allometric and 2.40, 2.27 and 2.27 respectively meaning the fish become lighter for its length as it grows. These values accounted for the robustness of the fish in Ologe. High correlation coefficient was observed in E. lacerta with r=0.76, 0.97, and 0.88 for unsex, male and female specimens respectively. 158 males and 64 females were caught giving 1male:0.41female sex ratio. This was significantly different (P>0.05) from the expected 1male:1female. Diet of the fish consisted of shrimps, plant materials and unidentified food mass. Presence of fish and shrimps in stomachs of the fish indicated its piscivorous and predatory tendency while plant materials connoted its herbivorous habit.

Morphometrical characterization of the Atlantic mudskipper species (Periophthalmus barbarus) (Linnaeus, 1766) (Perciformes; Gobiiae) from Abonema in Port Harcourt, Rivers State, Nigeria

“…The statistical classifiers didn't show any clear sub speciation and separation of our samples into further groupings. Like the data from three substations as sampled by Lawson (2010) [9] did not show any sub-division, so does our data. As such for our further research using molecular methods, we took samples from our whole collections.…”

“…Severally, they are generally called Atlantic, blue spotted and silver line mudskippers with the basis of these name being passed on across generations. In some other works that documents their morphometry and meristic characteristics, for instance Lawson and Aguda (2010) [9] , he referred to them as Periphthalmus papilio. The basis of this nomenclature is not stated.…”

The Effect of Inland Saline Groundwater on Growth, Maturation, and Osmoregulation of Common Carp

“…For understanding maturation, GW and GSI have been used widely as the most reliable indicators of maturation (Lawson and Olagundoye 2011). An adverse effect of salinity on the maturation of freshwater fishes has been reported by many researchers (Rajender 2000; Baxevanis et al 2004; Barman et al 2005).…”

Global conservation status and research needs for tarpons (Megalopidae), ladyfishes (Elopidae) and bonefishes (Albulidae)

“…One report of planktonic larval duration indicates that larval transport can occur over several weeks (Wheeler 2000). No validated method to determine annual growth has been reported, but length-frequency analyses suggest that only three-year classes occupy estuaries and nearshore habitats (Ugwumba 1989;McBride et al 2001;McBride and Horodysky 2004;Lawson and Aguda 2010), while examinations of scales and otoliths indicate that Elops species live at least 4-6 years (Blake and Blake 1981;Palko 1984). Gonad maturity occurs once fish leave the estuary, at sizes larger than 500 mm (Ugwumba 1989;Santos-Mart ınez and Arboleda 1993;McBride et al 2001).…”