Dr. Jyoti Saroj

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 d...

The present investigation deals with the assessment of diversity, composition and seasonal distribution of zooplankton in the nearshore waters of Gulf of Mannar. The present study consists of 35 species at three different sampling stations. In this investigation, maximum zooplankton species were recorded at station 1 and 3, i.e., Mandapam and Punnakayal. Decapods and Calanoids were the most dominant groups. The species diversity of zooplankton was comparatively more at station 1 as compared to station 2 and 3 whereas the density of zooplankton was found to be lower at station 1 (542 to 33, 519 nos. m-3) compared to station 2 (821 to 41, 624 nos. m-3) and station 3 (761 to 39, 648 nos. m-3). The maximum and minimum density were recorded during summer 2018 and post-monsoon 2018 respectively at all sampling stations. The species diversity index (‘H’) was highest at station 1 (1.55) and (1.55) and lowest at station 3 (1.10). The current investigation exhibited that the rich zooplankton ...

Coral reefs are some of the most diverse and valuable ecosystems of India. The coral reefs not only provide a sanctuary to a myriad of marine life but also play a key role in protecting the coastline from erosion. India has around 8,000 km of coastline. The major reef formations in India are restricted to the Gulf of Mannar, Palk bay, Gulf of Kutch, Andaman and Nicobar Islands and the Lakshadweep islands. Three major reef types (atoll, fringing and barrier) occur in India. While the Lakshadweep reefs are atolls, the others are all fringing reefs. This article reviews that the status, distribution, research and management of coral reefs in India. In India coral reefs are being damaged and destroyed at an increasing rate. They face a number of worsening anthropogenic threats, including bleaching, destructive fishing practices, pollution and climate change. The Reef condition is generally poor and declining in near shore waters and areas of high population density. Sedimentation, dredg...

The GIS based studies will give a clear picture of the spatio-temporal distribution of fishes in the selected study area and help in identification of critical fishing grounds and represents fundamental information for stock assessment in terms of fishery and marine biodiversity. This study investigated the spatio-temporal distribution and abundance of different life stages of common dolphinfish, Coryphaena hippurus (Linnaeus, 1758) off Saurashtra coast. Geographical coordinates of fishing and allied information on the time of fishing, depth of the fishing area as well as catch details were collected using a structured schedule, from selected gillnetters operated from Veraval. Information was mapped using a GIS software to get the spatio-temporal distribution of the species. It was observed that the grounds of small sized and medium sized C. hippuruswere in the waters off the southwest Saurashtra and northwest Saurashtra coast whereas that of large sized individuals was along the west Saurashtra coast. The favourable fishing grounds were in the deeper waters (> 200 m) along the southwest Saurashtra and northern Saurashtra coast.

Background: A study of the diversity, distribution and development of fish eggs and larvae as an integral part of a fishery research programme serves as a valuable aid in the proper management of fisheries. The study is also an essential prerequisite in understanding the spawning biomass of forecasting and trends of production. Information available on diversity of fish eggs from Indian waters is inadequate. The present study was conducted to understand the diversity and distribution of pelagic fish eggs in the nearshore waters of Gulf of Mannar. Methods: The present study conducted at three stations-Mandapam, Thoothukudi and Punnakayal in the waters of Gulf of Mannar, during 2017-2019. A total of 684 ichthyoplankton samples were collected. In the laboratory, the samples were sorted and identified. The diversity was calculated by Shannon-Weiner, Margalef richness index and Pielou’s evenness indices. All the diversity indices were done by using the PRIMER-E software. Result: Our inve...

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.

The GIS based studies will give a clear picture of the spatio-temporal distribution of fishes in the selected study area and help in identification of critical fishing grounds and represents fundamental information for stock assessment in terms of fishery and marine biodiversity. This study investigated the spatio-temporal distribution and abundance of different life stages of common dolphinfish, Coryphaena hippurus (Linnaeus, 1758) off Saurashtra coast. Geographical coordinates of fishing and allied information on the time of fishing, depth of the fishing area as well as catch details were collected using a structured schedule, from selected gillnetters operated from Veraval. Information was mapped using a GIS software to get the spatio-temporal distribution of the species. It was observed that the grounds of small sized and medium sized C. hippuruswere in the waters off the southwest Saurashtra and northwest Saurashtra coast whereas that of large sized individuals was along the west Saurashtra coast. The favourable fishing grounds were in the deeper waters (> 200 m) along the southwest Saurashtra and northern Saurashtra coast.

Coral reefs are some of the most diverse and valuable ecosystems of India. The coral reefs not only provide a sanctuary to a myriad of marine life but also play a key role in protecting the coastline from erosion. India has around 8,000 km of coastline. The major reef formations in India are restricted to the Gulf of Mannar, Palk bay, Gulf of Kutch, Andaman and Nicobar Islands and the Lakshadweep islands. Three major reef types (atoll, fringing and barrier) occur in India. While the Lakshadweep reefs are atolls, the others are all fringing reefs. This article reviews that the status, distribution, research and management of coral reefs in India. In India coral reefs are being damaged and destroyed at an increasing rate. They face a number of worsening anthropogenic threats, including bleaching, destructive fishing practices, pollution and climate change. The Reef condition is generally poor and declining in near shore waters and areas of high population density. Sedimentation, dredging and coral mining are damaging near shore reefs, while the use of explosives and bottom nets in fishing are damaging offshore reefs in specific sites. Although institutions and laws are sufficient in theory to manage and protect the reefs in India, authorities in the field have taken little effective action in implementing these laws.

The length-weight relationship ofcommon dolphinfish (Coryphaena hippurrus) were determined during 2015-16 from Saurashtra coast, Gujarat. The mean fork lengths (FL) of the species caught in the months of March (847 ± 138 mm) and December (809 ± 154 mm) were higher compared to January (672 ± 135 mm). Their mode lengths were higher in the months of March (810 mm) and December (850 mm), while it was lower in January (430 mm). The value of 'b' was higher in males as compared to females.