Spawning biology of the skipjack, Katsuwonus pelamis (Linnaeus) from Minicoy waters

One of the important technical approaches to investigate the resource characteristics of oceanic species of tunas is to study the phases of its life history. Subsequent to the results of investigations on spawning of skipjack in Minicoy waters by Raju (1964), there is no further information available on this aspect from the area. The present paper deals with the spawning of skipjack, Katsuwonus pelamis in Minicoy waters with particular reference to the reproductive process. Ova diameter measurements have been used to demonstrate the developmental changes that take place in the female gonads during the breeding season

Biology of the bait fishes Spratelloides delicatulvs (Bennet) and S. Japonicus (Houttuyn) from Minicoy waters

Spratelloides delicatulus is considered to be an excellent bait fish by Hawaiian fishermen (June 1951, Ikehara 1953, June and Reintjes 1953). This species, however, does not contribute to a good percentage of the bait\ud fish catch in Hawaii but whenever Stolephorus purpureus is not available as bait sufficiently, sprats are captured and made use as bait (Welsh 1950). S. delicatulus is the widely used sprat in the Indo-Pacific. Its poor survival in captivity is the main handicap (Ikehara 1953, June and Reintjes 1953, Wilson 1971, Lee 1973). Occurrence of this species is very seasonal in the Pacific Ocean and is available more during summer months (Welsh 1950, June 1951 Wilson 1963). Hida (1971) noted that S. delicatulus was abundant in lagoons of large atolls in Micronesia

Marine Fish Calendar. 13. Minicoy

A 'Marine Fish Calendar' for Minicoy is presented here based on the .data collected during April, 1984 to March, 1987. Pole and line and surface trolling gears were responsible for about 95.85% and 4.14% respectively of the total fish landed; catch by hooks and line was negligible (0.01 %)

Age and growth of Katsuwonus pelamis (Linnaeus) and Thunnus albacares (Bonnaterre) from Minicoy waters

The earliest estimate of growth of skipjack tuna in the Pacific Ocean was that of Aikawa (1937) who examined 20 specimens from the islands off the southern part of Izu Peninsula in the western Pacific and later Aikawa and Kato (1938) examined 20 specimens from the Palau Island area. Kawasaki (1955) estimated the growth of skipjack from the south western sea off Japan, based on the progression of modal groups. In a later publication Kawasaki (1963) gave additional estimates of growth rates based on the data from the area off north eastern Japan. Yokota et al. (1961) estimated the growth rates based on modal progression of skipjack from the Sulu Sea. Brock (1954) studied the growth of skipjack in the area of the Hawaiian islands by examining the progression of modes computed from length frequency studies. Rothschild (1967) estimated the parameters of growth for this species on the basis of 35 recoveries of fish tagged in Hawaiian waters -in 1958 which were at liberty upto 420 days. In the eastern Pacific, Schaefer et al. (1961) examined the growth of skipjack tagged during 1955-1959

355 BAIT-FISH AND TUNA CATCHES AT MINICOY ISLAND (LAKSHADWEEP) IN RELATION TO LUNAR CYCLE DURING 1983-84 SEASON

ABSTRACT The catches of bait-fish and tuna in relation to moon phases during 1983-84 pole-and-line tuna-fishing season is discussed. Bait-fish and tuna catches for the season as a whole were relatively high during new-moon phase and low 'during the last quarter of the moon. Tuna catches per kg of bait fish were high during the last quarter of moon and low during newmoon phase. Efforts in both bait fishing and tuna fishing and catehes-per-unit-of-effort of bait fishes and tuna were highest during newmoon phase, then decreased gradually and was lowest in the last quarters. Bait-fish catches at Minicoy have shown fluctation from year to year, creating problems to fishermen of the Island, because bait fish is very essential for successful pole-and-line operations. The fishermen at Minicoy believe that some important bait fishes appear in the lagoon only during certain moon phase. This study was undertaken during the 1983-84 tuna-fishing season to see whether moon phases really played important role in the availability of bait fishes as well as in the tuna catches at Minicoy. Data on daily bait-fish catches and the quantity of tunas caught were collected, the former by observing the bait wells or by enquiry from fisherme

राष्ट्रीय खाघ सुरक्षा केलिए उत्तरदायित्वपूर्ण मात्स्यिकी प्रबन्धन एक विकल्प

कृपया पूरा लेख पढे

BAIT-FISH AND TUNA CATCHES AT MINICOY ISLAND (LAKSHADWEEP) IN RELATION TO LUNAR CYCLE DURING 1983-84 SEASON

The catches of bait-fish and tuna in relation to moon phases during 1983-84 pole-and-line tuna-fishing season is discussed. Bait-fish and tuna catches for the season as a whole were relatively high during new-moon phase and low 'during the last quarter of the moon. Tuna catches per kg of bait fish were high during the last quarter of moon and low during newmoon phase. Efforts in both bait fishing and tuna fishing and catehes-per-unit-of-effort of bait fishes and tuna were highest during newmoon phase, then decreased gradually and was lowest in the last quarters

Comparative efficiency of live-baits for skipjack tuna Katsuwonus pelamis fishery at Minicoy

Skipjack tuna Katsuwonus pelamis are caught commercially at Minicoy by pole and line fishing using live-bait fishes. Relationship between live bait fish catches and skipjack tuna fishery during 1981-82 season is described here for the first time from Indian waters. An attempt is made here to compare the relative effectiveness of the different species of the bait fishes. The factors which may affect effectiveness of different live baits and ultimately tuna fishery at Minicoy are being discussed

Length-weight relationship of skipjack, Katsuwonus pelamis (Linnaeus) and yellowfin tuna Thunnus albacares (Bonnaterre) from Minicoy waters

One of the major objectives of the research programme on tunas at Minicoy Island, is to collect data on length frequency distribution of skipjack, Katsuwonus pelamis and yellowfin tuna Thunnus albacares which are caught by pole and line fishing. In order to utilize these length frequency data and to convert catch data from kilograms to number of fish for the purposes of estimating average weights and the population sizes, it becomes essential to estimate the length-weight relationship of these species

Mangrove ecosystems of Minicoy Island, Lakshadweep

Mangroves play an Important role in coral reef ecosystems. The fringe and basin type mangrove forests act as depositional areas and are effective binders of sediments. This reduces the sediment loads in coastal waters. Trapping and stabilizing sediments is important for adjacent coral reefs because it prevents abrasion and burial of reefs during stormy conditions