Asian Science Citation Index is committed to provide an authoritative, trusted and significant information by the coverage of the most important and influential journals to meet the needs of the global scientific community.  
ASCI Database
308-Lasani Town,
Sargodha Road,
Faisalabad, Pakistan
Fax: +92-41-8815544
Contact Via Web
Suggest a Journal
 
Articles by E.O. Lawson
Total Records ( 5 ) for E.O. Lawson
  E.O. Lawson , A.E. Thomas and A.A. Nwabueze
  Present study was conducted on Frill fin goby (Bathygobius soporator) to provide information on its abundance, morphometric measurements and growth patterns in Badagry creek, Lagos, Nigeria. A total of 506 individuals were caught from the creek between January 2008 and January 2009. They were caught with gill nets and non-return barrier traps. Biometric and morphometric data were obtained from the fish. Abundance of the fish was in favour of low rainfall and high salinity. Four hundred and seventy males and five females were encountered in the study, giving 1 male: 0.0106 female ratio. The morphometric data included eye diameter, which varied between 3-9(4.98±0.43) mm, head length ranged from 16-60 (39.15±4.9) mm and body depth, 20-70 (27.15±4.46) mm. The fish measured between 60 and 252 (131.21±17.68) mm total length, weighing 2.7 and 291.9 g b.wt, respectively. The populations of the species showed variations in their morphometric measurements which were not differ significantly (p≥0.05), indicating that the fish population may not be genetically diversified. These insignificant variations may be related to the geography, ecology and human activities of the creek. The fingerlings measured between 60-99 mm TL; juveniles, 100-149 mm TL and adults, 150 to 252 mm TL, representing 18.58, 55.14 and 26.28% of the population, respectively. The LWR was Log W = Log-1.56+1.43 Log L (r = 0.66) representing a negative allometric growth relationship. The condition factor for the fish was less than 2.890 g cm-3. This study therefore provides information on the biologic aspects of B. soporator as baseline data for its ecology, management and conservation in Badagry creek.
  E.O. Lawson and S.A. Alake
  A study was carried out in the laboratory on adaptability and tolerance of hatchery reared Comet goldfish, Carassius auratus (Linnaeus 1758) to varied salinity regimes, to provide baseline data and information on possibility of its culture in brackish water or marine environment. A total of two hundred and twenty life juvenile of goldfish, aged eight months used in this study were raised in and purchased from a reputable fish farm in Lagos, Nigeria. Biometric data on total length (T) and body weight (BW) measurements were recorded in the fisheries laboratory of Lagos State University. Goldfish of 17 to 25 cm total length, weighing between 70 and 145 g body weight were subjected to 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 parts per thousand (‰) salinities in the laboratory. There was a significant decrease in total length and body weight measurements with increased salinity. Mean growth rate (MGR) of 39.196, 34.783, 34.555, 20.889, 15.852 and 10.645 g day-1 were observed in 0, 1, 2, 3, 4 and 5 ‰, respectively, while the specific growth rates (SGR) were 0.012, 0.011, 0.008, 0.008, 0.005 and 0.005 g day-1, respectively. No death (0% mortality) was recorded in 0, 1, 2 and 3 ‰. The most adaptable salinity was 0 ‰; the fish however exhibited high level of tolerance between 1 and 5‰ salinities. The baseline data from this study indicate that gold fish, Carassius auratus will adapt and tolerate culture systems of fresh and low brackish water environments of 0 to 5 ‰ salinities.
  E.O. Lawson , P.A. Doseku and R.G. Ajepe
  The fish species assemblage and diversity of Majidun Creek, Lagos, Nigeria was investigated between January and December, 2010 to provide necessary baseline information that will help to maximize the sustainability of its fishery. Fish were collected with gill and cast nets. Associated environmental parameters such as water temperature and salinity were determined using mercury-in-glass thermometer and salinometer respectively. The specimens were sorted to the lowest taxonomic level and identified with identification manuals. Species diversity was determined by Simpson’s index while dominance and evenness by Shannon-Weiner index of diversity. The species assemblage comprised 517 individuals from 18 families, 8 orders, 20 genera and 23 species of fin and shell fishes. The dominant species were Sardinella aurita, Elops lacerta, Caranx hippos and Mugil cephalus with 256, 90, 59 and 29 individuals representing 49.52, 17.41, 11.41 and 5.61% of total fish catch respectively. The diversity indices’ estimates were Simpson’s Index (D) = 0.292, Simpson’s Index of diversity (1-D) = 0.708, Simpson’s Reciprocal Index (1/D) = 3.423, Shannon-Weiner Index (H) = 1.799, Shannon’s equitability (eH) = 0.574, Evenness (E) = 0.263 and Margalef Index (Dmn) = 3.52. Salinity and rainfall greatly influenced the species richness and diversity. High number of juvenile fish in this study is as indication that the creek served as a veritable spawning, breeding or feeding ground for freshwater and marine species. This study is an important contribution to fisheries of this creek where there is paucity of information concerning its fishes and fisheries.
  E.O. Lawson
  Study was carried out on mudskipper, Periophthalmus papilio in Lagos lagoon, Nigeria to provide information on length-weight relationship and fecundity estimates. Periophthalmus papilio is of an amphibious fish and a member of the family periophthalmidae. A total of 2,167 individual of the specie were caught from the lagoon using non return valve traps. Biometric data such as Total Length (TL) and Body Weight (BW) measurements were recorded in the laboratory. The specimens ranged from 30.0 to 190.0 mmTL and weighed between 0.5 and 65.3 g BW. The mean TL measurements were 76.0566±1.415, 115.953±0.999 and 111.361±0.812 mm and weighing 5.908±0.393, 18.808±0.507 and 16.769±0.367 g for unsex, males and females, respectively. The length weight relationships were: Log W = -4.1053+2.5522 Log TL (n = 185, r = 0.9385) for unsex; Log W = -4.6804+2.8606 Log TL (n = 532, r = 0.9684) for males and Log W = -4.7916+2.915 Log TL (n = 746, r = 0.9784) for females. The growth exponential b values were allometry in this species. The fecundity estimates of the species varied between 508 and 15,700 ripe eggs for fish with size from 91-180 mmTL and 9.1-65.3 gBW. The mean fecundity estimate was 3,482±102 eggs for average fish of 116 mmTL. Positive correlation was exhibited by the fish between its fecundity and body weight (r = 0.4041) and total length (r = 0.3810). The Gonadosomatic Index (GSI) values of the fish varied between 0.01 and 0.48% in males and 0.11-8.40% in females. Higher GSI values indicate a better well being for the fish.
  J.I. Agboola , M.A. Adewolu and E.O. Lawson
  The Millennium Ecosystem Assessment (MA) has identified climate change as one of the main drivers of change in aquatic biodiversity and ecosystem with a very rapid increase of the impact. Recently, the Intergovernmental Panel on Climate Change (IPCC) concluded that climate change is, without doubt, occurring and that the Earth is warming. There are some climate change winners, but scientists predict that the overwhelming effect of climate change upon biodiversity including fisheries will be damaging. The nexus between climate change, fisheries and phytoplankton is particularly strong. This study considers this ‘non-fishing effects’ on fish abundance and distribution by exploring the various roles of phytoplankton in climate change and fisheries productivity. It then discusses the need to improve our knowledge of phytoplankton as mechanisms linking climate to ecosystem changes such as fisheries productivity.
 
 
 
Copyright   |   Desclaimer   |    Privacy Policy   |   Browsers   |   Accessibility