scholarly journals Length frequency distribution of Ethmalosa fimbriata (Bowdich) in cross River Estuary and Adjacent Coastal waters

2002 ◽  
Vol 8 (3) ◽  
Author(s):  
D.E. Ama-Abasi ◽  
S. Holzloehner
Keyword(s):  
Frequency Distribution ◽  
Coastal Waters ◽  
River Estuary ◽  
Length Frequency Distribution ◽  
Length Frequency ◽  
Cross River ◽  
Cross River Estuary

Age and growth pattern of the thin-lipped mullet Liza Ramada in the Eastern coast of Libya.

2016 ◽  
Vol 5 (06) ◽  
pp. 4620
Author(s):  
Manal M. Khalifa ◽  
Ramadan A. S. Ali ◽  
Abdalla N. Elawad* ◽  
Mohammad El. ElMor
Keyword(s):  
Frequency Distribution ◽  
Age Groups ◽  
Age Determination ◽  
Age And Growth ◽  
Eastern Coast ◽  
Growth Equation ◽  
Length Frequency Distribution ◽  
Length Frequency ◽  
Scale Reading ◽  
Von Bertalanffy Growth Equation

Age and growth characteristics of the thin-lipped Grey Mullet (Liza ramada) were investigated in Eastern coast of Libya. Aging was done by two methods: counting annuli on scales and by length frequency distribution, a total of 218 scales were studied for age determination, in addition of 334 fishes specimen for length frequency distribution reading. Four age groups were determined from scale reading, and five age groups from length frequency distribution methods, the parameters of the Von Bertalanffy growth equation for both sex of all individuals were estimated at 35.4 cm, 0.187 per year, -1.14 years and 2.4, for male were estimated at 35.7 cm, 0.17 per year, -1.367 and 2.3, for female were 38.6 cm, 0.156 per year, -1.383 and 2.4, for L∞, k and t0, and φ′, respectively.

scholarly journals Age, Growth and Ovarian Histology of Sardinella aurita (Valenciennes, 1847) in the South of Atlantic Moroccan Coast

2021 ◽  
Vol 21 (04) ◽  
pp. 191-204
Author(s):  
Ayoub Baali ◽  
Oum Keltoum Belhsen ◽  
Khalil Chahdi Ouazzani ◽  
Khadija Amenzoui ◽  
Ahmed Yahyaoui
Keyword(s):  
Frequency Distribution ◽  
Stock Assessment ◽  
Atlantic Coast ◽  
Age Groups ◽  
Age Determination ◽  
Length Frequency Distribution ◽  
Length Frequency ◽  
The South ◽  
Moroccan Coast ◽  
Sardinella Aurita

Otoliths reading and length frequency distribution were used for age determination and growth estimation of Sardinella aurita (round sardinella) stock of Southern Atlantic coast of Morocco. Both otoliths' method for age determination and Bhattacharya’s method for length frequency analysis showed five age groups. The growth performance index revealed that there is significant accordance among method of length frequency distribution and otoliths reading for stock assessment studies of Sardinella aurita stock in the south of Morocco. The microscopic observation of female gonads using histology method was investigated for the first time in our study area and confirms the presence of five principal stages of ovary of sardinella aurita: immature, maturing virgin and recovering spent, mature (or pre-spawning phase), spawning, post-spawning or spent. In addition, our results of the fecundity showed that the mean relative fecundity obtained is estimated at 193 ± 98 oocytes/g which is lower compared to those obtained in other areas in the Atlantic coast.

Studies on fecundity and spawning of blue crab (Callinectes Amnicola) in Cross River Estuary

2021 ◽  
Vol 36 (1) ◽  
pp. 75-82
Author(s):  
J. Otoyo ◽  
S.M. Ameh ◽  
O.K. Achema
Keyword(s):  
Blue Crab ◽  
Egg Size ◽  
Gonadosomatic Index ◽  
Carapace Width ◽  
River Estuary ◽  
Hepatosomatic Index ◽  
Cross River ◽  
The Cross ◽  
Cross River Estuary ◽  
Egg Diameter

Studies on identification of species, fecundity and development stages of blue crab, (Callinectes amnicola) were investigated at the Cross River Estuary between the months of December, 2018 and May, 2019. The parameters used for the study were gonadosomatic and hepatosomatic indices, egg diameter and counts. All measurements followed standard procedures. Gonadosomatic index was at its peak in December (88.9) and April (83.3). This coincided with the peak in egg size suggesting that spawning occurred twice within the period.The low values of hepatosomatic index around December (1.20) and April (0.45) added to confirm the spawning in these months. The species spawns at a mean egg size of 17.55mm. The dimension of crabs examined were in the following range: carapace length 40.0 to 70.0mm, carapace width, 5.0 to 60mm and body weight 40.0 to 140.0g. The relationship between fecundity and weight of crab was  significant (r = 0.295: p<0.05), indicating positive correlation. Absolute fecundity of the species ranged between 1,375 and 225,132 eggs. The smallest crab with egg had a carapace width of 39.5mm and weight of 46.9g. Spawning at this size seems to be a strategy adopted by the species to cope with exploitation pressure. The result of this study revealed that C. amnicola had a high reproductive potentials. Hence, adequate regulation is required to enhance sustainability of the species in the Cross River Estuary.

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