scholarly journals Reproductive biology of the commercially important Indian squid Uroteuthis (Photololigo) duvaucelii (d’ Orbigny [in Ferussac & d’ Orbigny], 1835) off Mangalore, south-west coast of India

2017 ◽  
Vol 64 (1) ◽  
pp. 75
Author(s):  
N. Rajendra Naik ◽  
S. M. Shivaprakash ◽  
H. N. Anjaneyappa ◽  
S. R. Somasekhara ◽  
Jaya Naik ◽  
...  

Uroteuthis (Photololigo) duvaucelii is one of the commercially important inshore squid resources off the south-west coast of India. Length-weight relationship for this species indicated no significant difference between the sexes and hence, the relationship for both the sexes was represented with the common equation W = 0.4624 L2.1158. U. (P.) duvaucelii spawned throughout the year with peak spawning in May. Absolute fecundity ranged from 1,545 to 13,585 eggs with an average of 7,554 eggs. Size at first maturity indicated that females matured earlier at 70 mm DML (dorsal mantle length) whereas males matured little later at 90 mm DML. Males were observed to be dominant during most of the study period with overall male to female ratio of 1:0.93. Seasonal and size dependent variations in sex ratio were distinct.

2017 ◽  
Vol 64 (4) ◽  
Author(s):  
D. Arunjenish ◽  
N. Neethiselvan ◽  
B. Sundaramoorthy ◽  
P. Jawahar ◽  
T. Ravikumar

The efficiency of four different funnel designs viz., rectangular, oval, heart-in and circular shaped funnels were tested in a serial collapsible fish trap through fishing trials conducted in a coastal fishing ground off Mandapam in Tamil Nadu, south-west coast of India. A total of 24 fishing operations were carried out. Significant difference in overall catch rate of experimental trap with respect to funnel designs could be observed (p<0.05). Among four types of funnels tested with the constant rear end funnel perimeter of 560 mm, traps with oval funnel caught more number of fishes (121 nos. in 24 soaking days) than those fitted with rectangular, heart-in shaped and circular type of funnels with 37; 82 and 70 nos. in 24 soaking days respectively. The study revealed that oval shaped funnel was superior to the other funnel designs with 560 mm circumference.


2021 ◽  
Vol 42 (1) ◽  
pp. 112-117
Author(s):  
K.M. Rajesh ◽  
◽  
P. Rohit ◽  
E.M. Abdussamad ◽  
◽  
...  

Aim: The present study was conducted to investigate the fishery, diet composition and reproductive aspects of obtuse barracuda landed in Karnataka, south-west coast of India. Methodology: Feeding and reproductive traits of 1229 samples (638 males and 591 females) of S. obtusata was studied for a period of five years. The index of relative importance (IRI) was determined for each diet component in the stomach. Reproductive aspects such as maturity stages, gonadosomatic index and fecundity were investigated. Results: The most predominant prey item in terms of frequency of occurrence (93.1%), number (91.4%), weight (93.2%), IRI (3615.5) and also % IRI (98.5%) was fishes. Crustaceans and cephalopods were noticed less frequently and were represented by shrimps and Loligo sp. The estimated length at first maturity for male and female fishes was 20.5 and 21.3 cm, respectively. Higher GSI values were observed during post monsoon (October-November) followed by summer pre monsoon (April-May) season in both males and females, indicating two peak spawning periods. Interpretation: The comprehensive study on major biological characteristics of Sphyraena obtusata could be useful for developing appropriate management strategies for conservation and judicious exploitation of this commercially important resource. Key words: Barracuda, Fecundity, Gonadosomatic index, Sphyraena obtusata


2019 ◽  
Vol 66 (1) ◽  
Author(s):  
K.M. Rajesh ◽  
Prathibha Rohit ◽  
K.G. Mini ◽  
T. Sathyavathi ◽  
M.M. Abdul Hakeem

A comprehensive study on fishery, length-weight relationship, trophodynamics and reproductive aspects of the blackbanded trevally Seriolina nigrofasciata (Ruppel, 1829), collected during January 2013 to December 2017 from fishing vessels operating along eastern Arabian Sea off south-west coast of India was conducted. Among the maritime states of the country, Karnataka was the major contributor (53.9%) followed by Kerala (24.1%), Maharashtra (16%) and Tamil Nadu (4.3%). In Karnataka, 99.5% of the blackbanded trevally catch was exploited by trawl net and rest by outboard gillnets (0.5%). The total length ranged from 16.3 to 57.5 cm with fishes in the size range of 24 to 36 cm forming 80.8% of the catch. The length-weight relationship estimated showed a negative allometric growth for both sexes with b values of 2.595 for females and 2.504 for males. The estimated ‘a’ values for females and males were 0.00013 and 0.00021 respectively. In all, fifteen prey items under three major groups (teleosts, cephalopods and crustaceans) comprised the diet, with teleosts (73.23%) being the predominant food item followed by cephalopods (26.53%) and crustaceans (0.24%) in terms of index of relative importance (IRI). Overall sex ratio (male: female) of 1:1.15 indicated a slight dominance of females over males. The length at first maturity was estimated at 25.0 cm for male and 27.0 cm for female. The availability of mature and spent specimens all through the year implied that the species has prolonged spawning period with a peak during the summer season (March-May) and a minor secondary peak in post-monsoon season (October to December).


2013 ◽  
Vol 65 ◽  
pp. 45-51 ◽  
Author(s):  
Asha S. Philip ◽  
C.A. Babu ◽  
P.V. Hareeshkumar

2017 ◽  
Vol 33 (6) ◽  
pp. 1308-1309 ◽  
Author(s):  
S. K. Roul ◽  
A. R. Akhil ◽  
T. B. Retheesh ◽  
D. Prakasan ◽  
U. Ganga ◽  
...  

2001 ◽  
Vol 81 (6) ◽  
pp. 724-728 ◽  
Author(s):  
H. M. Mahesh ◽  
D. N. Avadhani ◽  
N. Karunakara ◽  
H. M. Somashekarappa ◽  
Y. Narayana ◽  
...  

2020 ◽  
Vol 89 (sp1) ◽  
pp. 150
Author(s):  
Ravindran Prasad ◽  
Leela Sheela Nair ◽  
Njaliplackil Philipose Kurian ◽  
Thirumali Nageshrao Prakash

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