scholarly journals Fishery, diet composition and reproductive biology of the dolphinfish Coryphaena hippurus (Linnaeus, 1758) off Karnataka, south-west coast of India

2016 ◽  
Vol 63 (4) ◽  
Author(s):  
K. M. Rajesh ◽  
Prathibha Rohit ◽  
E. M. Abdussamad
Keyword(s):  
Reproductive Biology ◽  
Diet Composition ◽  
Gradual Increase ◽  
Gonadosomatic Index ◽  
Fork Length ◽  
Spawning Period ◽  
Coryphaena Hippurus ◽  
South West ◽  
South West Coast ◽  
Index Of Relative Importance

Fishery, diet composition and reproductive biology of the dolphinfish Coryphaena hippurus (Linnaeus, 1758) landed along Karnataka Coast during 2013-15 were studied. The estimated average landing of the species in India during the study period was 7975 t of which Karnataka contributed 2.73% (218 t). The fish is mainly exploited by gillnet and also by troll lines operated from trawlers. A few stray specimens were also landed by purse seines. The fork length (FL) was in the range of 32-128 cm and fishes in the length range (FL) of 55-90 cm dominated the catch, contributing 79.8% of the total landings. The most dominant prey item, in terms of occurrence (70.57%) and weight (83.18%) were finfishes followed by cephalopods (19.62% by occurrence and 13.66% by weight) and crustaceans (7.01% occurrence and 1.32% by weight). The index of relative importance (IRI ) values were 85.3, 13.39 and 0.68% respectively for fish, cephalopods and crustaceans respectively. Sex ratio (1:2.05) indicated dominance of females in the fishery. Presence of mature and spent specimens throughout the year suggests that the species spawns all through the year. Peak spawning period was from June to September. This coincided with gradual increase in gonadosomatic index (GSI) values ahead of May which reached a peak during August-September.

First report on the diet and reproductive biology of red-toothed triggerfish Odonus niger (Ruppell, 1836) from the south-eastern Arabian Sea

2021 ◽  
pp. 1-11
Author(s):  
Nitin Kanji Suyani ◽  
Mridula Rajesh ◽  
Kothanahally Mallegowda Rajesh
Keyword(s):  
Reproductive Biology ◽  
Arabian Sea ◽  
Feeding Habits ◽  
Gonadosomatic Index ◽  
Biological Information ◽  
The South ◽  
Spawning Period ◽  
South Eastern ◽  
Eastern Arabian Sea ◽  
Males And Females

Abstract The feeding habits and reproductive biology of red-toothed triggerfish Odonus niger (Ruppell, 1836) was analysed from 449 specimens collected from the Karnataka coast of the south-eastern Arabian Sea. Of the total stomachs examined, only 54 (12%) were empty and 395 contained food remains. The diet comprised crustacean remains (48.0%), zooplankton (21.4%), algae (16.5%), fish remains (6.1%) and cephalopod remains (5.3%) along with partially digested matter (2.3%) and detritus (0.4%). The species was found to be a generalist feeder and an omnivore. The overall sex ratio between males and females (1: 0.44) was significantly (P < 0.05) different. Histological examination of the ovaries indicated asynchronous ovarian development in females, with males maturing earlier than females. The gonadosomatic index (GSI) patterns of males and females, and the presence of ripe ovaries and spermatozoids suggested that April–May is the peak spawning period. The absolute and relative fecundity estimates ranged from 16,464–312,420 eggs and 251–2812 eggs g−1 respectively. Fecundity was positively correlated with total length and body weight. The biological information on diet composition and reproductive traits provided for the first time in this study can facilitate conservation, management and sustainable exploitation of this species in the study area.

Some aspects of reproductive biology of Gobius paganellus (Gobiidae) on the north-eastern coasts of Tunisia (Bizerta lagoon)

2013 ◽  
Vol 93 (8) ◽  
pp. 2235-2246 ◽  
Author(s):  
Ibtissem Louiz ◽  
Mossadok Ben Attia ◽  
Oum Kalthoum Ben Hassine
Keyword(s):  
Sex Ratio ◽  
Reproductive Biology ◽  
Gonadosomatic Index ◽  
Length Distribution ◽  
Sexual Cycle ◽  
Hepatosomatic Index ◽  
Gobiid Fish ◽  
Spawning Period ◽  
North East ◽  
Bizerta Lagoon

The rock goby, Gobius paganellus one of the most common gobiid fish in Bizerta lagoon (north-east of Tunisia), is a gonochoric species that belongs to the Gobiidae family. This study provides the first detailed information of its reproductive biology in lagoon environments. Gobius paganellus was sampled monthly from January 2005 to December 2006 involving 1486 specimens. Total length distribution ranged between 38 and 125 mm. The maximum recorded total lengths were, respectively, 122 mm and 125 mm for female and male. Over the entire population, the sex-ratio was unbalanced in favour of females. According to months, a predominance of females sex-ratio was recorded during the spawning period while according to body size, males were dominating among larger size-classes. In both sexes, the variation of the gonadosomatic index (GSI) was independent of size. Macroscopic and microscopic examination of the gonads added to the monthly monitoring of gonadosomatic index and hepatosomatic index showed that gonads development begins in October and spawning period extends from December to March. The cyclic pattern of gonads development was determined by histology. Results indicated that G. paganellus exhibits a group-synchronous oocyte development. The sizes of first sexual maturity related to 50% of mature individuals were 78.3 mm (CI95: 77–84 mm) for males and 79 mm (CI95: 75–85 mms) for females. The discussion part underlined the impacts of some environmental factors and antropization of this lagoon on sexual cycle of G. paganellus.

Reproductive characteristics and per-recruit analyses of blue warehou (Seriolella brama): implications for the South East Fishery of Australia

2001 ◽  
Vol 52 (4) ◽  
pp. 575 ◽  
Author(s):  
Ian A. Knuckey ◽  
K. P. Sivakumaran
Keyword(s):  
Egg Production ◽  
East Coast ◽  
Gonadosomatic Index ◽  
Fork Length ◽  
Size At Maturity ◽  
Current Management ◽  
Spawning Period ◽  
Gill Net ◽  
Trawl Fishing

Monthly samples of commercial catches of S. brama were collected between May 1996 and December 1997 in three regions of the fishery:off the east coast of Victoria; eastern Tasmania; and western Bass Strait. Sex ratio, gonadosomatic index, macroscopic and histological development, size at maturity and fecundity were estimated and combined with data on growth and mortality to perform per-recruit analyses. The main spawning period was during winter–spring and there was evidence of spawning in each of the three regions. Blue warehou reach maturity at 30–40 cm fork length. They have a determinate annual fecundity and spawn around three batches of eggs during a season. Eggs-per-recruit analyses revealed maximum egg production at ~40 cm (4–5 years) in an unfished population. Gill-net fishing, which targets fish >45 cm, was less likely to affect the relative eggs-per-recruit in a population than trawl fishing, which catches a wider range of smaller fish. These results are discussed in light of the current management arrangements in the fishery and will be used in models to assess the effect of fishing on the long-term sustainability of the blue warehou.

scholarly journals Reproductive biology of Penaeus kerathurus (Forskål, 1775) (Decapoda: Penaeidae) in the Sea of Marmara, Turkey

2021 ◽  
Vol 50 (1) ◽  
pp. 33-37
Author(s):  
Mukadder Arslan Ihsanoglu ◽  
Ismail Burak Daban ◽  
Ali Işmen ◽  
Koray Cabbar ◽  
Cahide Çiğdem Yığin
Keyword(s):  
Reproductive Biology ◽  
Sexual Maturity ◽  
Carapace Length ◽  
Gonadosomatic Index ◽  
Mediterranean Ecosystem ◽  
Sea Of Marmara ◽  
Important Species ◽  
Spawning Period ◽  
Male Ratio ◽  
First Reproduction

Abstract One of the economically important species is Penaeus kerathurus (Forskål, 1755), which is widespread in the Mediterranean ecosystem. This paper presents results of research on reproductive biology of Penaeus kerathurus in the Sea of Marmara. A total of 1404 specimens were dissected to determine the maturity stages, reproduction time, and length at first reproduction. The female-to-male ratio was 1:0.9. A high percentage of mature females was determined in April, May and July. Moreover, the value of the gonadosomatic index (GSI) decreased after July. The spawning period was observed between April and July, and its intensity increased in July. The carapace length at first sexual maturity was determined to be 39 mm.

scholarly journals Food and feeding habits of the narrow barred Spanish mackerel, Scomberomorus commerson (Lacepede, 1800) off Karnataka, south-west coast of India

2017 ◽  
Vol 64 ◽  
Author(s):  
K. M. Rajesh ◽  
P. Rohit ◽  
S. Thomas ◽  
V. Suprabha ◽  
G. D. Nataraja ◽  
...  
Keyword(s):  
Feeding Habits ◽  
Fork Length ◽  
Empty Stomach ◽  
Spanish Mackerel ◽  
Scomberomorus Commerson ◽  
South West Coast ◽  
Food And Feeding ◽  
Fish Remains ◽  
Index Of Relative Importance ◽  
Almost All

Scomberomorus commerson were collected on weekly basis during January 2012 to December 2014 at Mangalore Fishing Harbour. Stomach of 214 narrow barred Spanish mackerel measuring from 48 to 105 cm fork length (FL) for males and 45.5 to 115 cm FL for females were analysed to study their feeding habits. Fish with empty stomach were prevalent in almost all the months. Prey mainly comprised of fishes and crustaceans, with the fish component forming 99.9%. The index of relative importance (IRI) showed that the dominant prey were semi-digested fish remains (44.6%) of Sardinella longiceps (30.1%), Decapterus sp. (18.7%), whitebaits (2.5%), Rastrelliger kanagurta (1.5%) and Epinephelus spp. (1.1%), while Saurida sp. (0.7%), Megalaspis cordyla (0.5%), Scombroides sp. (0.2%) and shrimps (0.1%) were found occasionally in the gut. Index of stomach fullness (SFI) was 0.11 in August and 0.65 in January. Generally, SFI was higher during September to January and lower during February to August. The empty stomach ratio (ESR) ranged from 33.3% (August) to 92.3% (April).

scholarly journals Reproductive biology and feeding habits of the common dolphinfish Coryphaena hippurus (Linnaeus, 1758) off Saurashtra coast, India

2018 ◽  
Vol 65 (4) ◽  
Author(s):  
Jyoti Saroj ◽  
K. Mohammed Koya ◽  
K.L. Mathew ◽  
Panja Tehseen
Keyword(s):  
Reproductive Biology ◽  
Feeding Habits ◽  
Fork Length ◽  
Reproductive Activity ◽  
Monthly Basis ◽  
Coryphaena Hippurus ◽  
Saurashtra Coast ◽  
The Common ◽  
One Year ◽  
The One

The present study analysed reproductive biology and feeding habits of the common dolphinfish Corphaena hippurus, along the Saurashtra coast of India. The study is based on an investigation of 295 specimens caught using drift gillnet at Veraval. The samples were collected on a monthly basis between March 2015 and February 2016. The sex ratio was 1:1.75 with a significant dominance of females in the population. The size at maturity for females was 593 mm FL (fork length). Absolute fecundity of the individuals ranged from 1,07,813 to 15,50,400 having ova diameter range of 0.3-1.96 mm. C. hippurus spawned throughout the year with its reproductive activity peaking in April and December. Thus the dolphin fish has an extended spawning season; during which it laid eggs almost continuously. A total of 128 stomachs of C. hippurus, whose fork length FL ranged from 380 to 1250 mm were examined during the one year period of this study. Tunas were found to be the common dietary component of the dolphinfish.

Reproductive dynamics of broadbill swordfish, Xiphias gladius, in the domestic longline fishery off eastern Australia

2003 ◽  
Vol 54 (4) ◽  
pp. 315 ◽  
Author(s):  
Jock Young ◽  
Anita Drake ◽  
Michael Brickhill ◽  
Jessica Farley ◽  
Thor Carter
Keyword(s):  
New Zealand ◽  
Gonadosomatic Index ◽  
Fork Length ◽  
Reproductive Period ◽  
Fish Length ◽  
Batch Fecundity ◽  
Spawning Period ◽  
Fish Size ◽  
Eastern Australia ◽  
Xiphias Gladius

The reproductive ecology of broadbill swordfish, Xiphias gladius, was evaluated based on 1437 fish (size range 50–300 cm orbital fork length [OFL]) caught in the domestic longline fisheries off eastern Australia and New Zealand between May 1999 and March 2001. Reproductive activity was assessed using histology, a gonadosomatic index, and maximum oocyte size. Males were significantly smaller than females and represented less than one third of the sampled fish. Sex ratio differed significantly with respect to fish size and time of year. Females began maturing at 150-cm OFL and spawned from September to March, with the greatest activity from December to February. Males matured at 90-cm OFL; ripe males were found from January to March, but also in May and October, suggesting an extended reproductive period. During the spawning period the proportion of spawning to inactive mature sized females was significantly higher in waters west of longitude 158°E than in waters to the east. Further to the east, samples taken from the New Zealand fishery showed no actively spawning fish during the main spawning period. Females were increasingly reproductively active as water temperature increased beyond 24°C and sea surface chlorophyll a decreased below 0.2 μg L–1. Batch fecundity was linearly related to fish length with a mean batch fecundity of 1.66 million oocytes for females ranging in size from 173- to 232-cm OFL. The presence of hydrated oocytes and post-ovulatory follicles (POFs) in the same ovaries indicated multiple spawnings. Depending on the time taken for POFs to degrade, these may have been daily at the height of the spawning season.

scholarly journals The length-weight relationship, condition factor and reproductive biology of Pseudotolithus (p) senegalensis (valenciennes, 1833) (croakers), in Tombo western rural district of Sierra Leone

2014 ◽  
Vol 14 (66) ◽  
pp. 9376-9389
Author(s):  
JO Olapade ◽  
◽  
S Tarawallie
Keyword(s):  
Sex Ratio ◽  
Sierra Leone ◽  
Reproductive Biology ◽  
Condition Factor ◽  
Gonadosomatic Index ◽  
Hepatosomatic Index ◽  
Allometric Growth ◽  
Spawning Period ◽  
Weight Relationship ◽  
Spawning Behaviour

The length – weight relationship (LWR), condition factor (K), sex ratio, gonadosomatic index (G S I) and hepatosomatic index (H S I) of 412 specimens of Pseudotolithu s s enegalensis (Valenciennes, 1833) from Tombo , a coastal fishing community in the western rural district of Sierra Leone were studied for twelve months . Samples used for the study were collected from the catches of artisanal fishers and measurement s of length and weight of samples were done in situ using the facilities of the Ministry of Fisheries and Marine Resources. Samples for the reproductive study were preserved in an ice box and taken to the laboratory of the Department of Aquaculture and Fisheries Management, Njala University , Sierra Leone for analysis. The parameters "a" and "b" of the length - weight relationship were estimated using the equation described by Ricker ( W = aL b ) while the condition factor was calculated using Fulton`s equation (K = W1 00 / L 3 ) . The reproductive biology of the fish was estimated using Gonadosomatic index ( GSI ) and Hepatosomatic index ( H S I ) . The combined LWR for both sexes showed that a, b and r values were – 2.57 , 3. 3 5 and 0. 899 , respectively. The r – values obtained show a strong linear relationship between the length and weight of the species. The length - weight relationship indicated allometric growth for P . senegalensis in the study area. The condition factor (K) varied from 0.64 – 1.0 ; this may be attributed to environmental conditions of the water . The species clearly exhibited a positive allometric growth pattern ( tα ( 2) , 0.05, 411 > 1.965) . The sex ratio of males to females was 1:1. 15 and was not significantly different from the expected 1:1 ratio. Estimation of GSI and HSI was carried out from December, 2010 to May, 2011 to determine the spawning behaviour of P. senegalensis . The mean GSI obtained indicate d that March and April , respectively are the two peak spawning period for the species . Gonado somatic index ranged between 1.1 % and 2.8% for the females. The results of this study revealed that P. senegalensis doe s not have obligatory spawning month but exhibit multiple spawning behaviour. T he length - w eight relationships and condition factor of the study indicated that the fish were thriving very well in the coastal water of Sierra Leone. Sustainable management of the species , therefore , require s that the environment be protected against anthropogenic pollution and imposition of closed fishing season especially during the t wo peak spawning period is recommended to enable the species recruit effectively.

scholarly journals Fishery and biological traits of obtuse barracuda Sphyraena obtusata (Cuvier, 1829) off south-west coast of India

2021 ◽  
Vol 42 (1) ◽  
pp. 112-117
Author(s):  
K.M. Rajesh ◽  
◽  
P. Rohit ◽  
E.M. Abdussamad ◽  
◽  
...  
Keyword(s):  
West Coast ◽  
Gonadosomatic Index ◽  
Management Strategies ◽  
Reproductive Traits ◽  
Biological Traits ◽  
West Coast Of India ◽  
South West ◽  
South West Coast ◽  
First Maturity ◽  
Spawning Periods

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

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