Note on a hermaphroditic gonad in the Indian Mackeral Rastrelliger canagurta (Cuvier)

While examining a sample of mackerel brought from UUal, a fishing village five miles from Mangalore, on 1st May 1961, a hermaphroditic gonad was observed in one specimen. The fish measured 221 mm, in total length and was normal to all outward appearance. Internally 'also, apart from this hermaphroditic gonad, no other abnormalities were noticed. Parasitic infection was not seen in the body cavity

Spawning behaviour and fecundity of the indian mackerel, Rastrelliger kanagurta (Cuvier), at Mangalore

The earliest reference to the fecundity of the Indian mackerel was by Devanesan and John (1940) who estimated the number of ripe eggs in the mackerel ovary as 94,000. Subsequent work was directed mostly towards finding out the spawning behaviour of this fish, by the study of the intra-ovarian eggs. Pradhan (1956) indicated the possibility of the Indian mackerel spawning the eggs in successive batches over a prolonged period, like its Atlantic counter-part Scomber scombrus (L). Pradhan and Palekar (1956) described the maturity stages I to VII, based on the external appearance of the ovary, its size relative to the abdominal cavity, and the range of ova-diameter readings. However, they have not given any ova-diameter frequency polygons

On the mackerel fishery of the Mangalore area during the period 1957-61

At Mangalore, studies on the mackerel fishery were initiated in 1957. The programme of work was intensified from 1958 onwards and detailed observations were made particularly at Ullal, an important fishing centre near Mangalore. This paper deals with certain interesting observations made during the years 1957-61 at Ullal and other centres in the region between Kasargod and Malpe, especially in regard to growth, maturity, and trends of catches. The von Bertalanffy growth equation has also been applied to the length-frequency data and tentative estimates of the parameters obtained. In order to study the variation in catches in relation to certain factors, the data collected by one of us (K. V. S.) at Malpe during 1954-55 have been incorporated

Observations on the Mackerel Fishery of the Netravati Estuary, West Coast, South India

The present communication relates to observations on an unusual fishery of the Indian Mackerel Rastrelliger kanagurta (Cuvier) in the Netravati estuary near Mangalore, lasting for about nine weeks from the latter half of January 1958. Normally the mackerel fishery is most active along the Konkan, Kanara, and Kerala coasts during the September-March period, and the catches comprise mostly immature forms ranging from 180-215 mm. in total length. There are no previous records of mackerel fishery of any appreciable extent from our estuaries, although Pradhan (1956) has recorded the fish entering the estuarine waters of the Kali River at Karwar

A note on the whale shark Rhincodon typus Smith, stranded off Mangalore

On the 5th March 1959, the trainees from the Fishery Training Centre were engaged in experimental purse seine fishing about four miles off Suratkal, an active fishing centre about ten miles north of Mangalore. At mid-day, during the low tide, they sighted a shark stranded in 2-3 fathom waters. Since the trainees were on a routine fishing trip they were poorly equipped for the capture of such giant fishes ; nevertheless, the shark was fastened with a two-foot hook in the caudal fin and in its struggle it dragged the two boats a few miles out into the sea. However, by evening it became exhausted, and next morning the dead shark was towed ashore

Exploratory trawling on the continental shelf along the north-western part of the Bay of Bengal

The results of exploratory trawl'ng undertaken from 1961 to 1965 on the continental shelf along the north-western part of the Bay of Bengal, between latitudes 16''40'N and 2rOO'N are presented. The composition of the catch, the distribution of the various categories of fishes and their relative abundance in space and time are indicated. It is estimated that in commercial fishing, with Visakhapatnam as the base, a 25 m side-trawler with 15 m trawl should be able to land 250-390 metric tons of fishes, a 14 m stern-trawler with 14m trawl, 67-174 metric tons, and a 13-7 m stern-trawler with 12 m trawl, 56-94 metric tons per year from the area

Pelagic fishery resources of Lawson’s bay, Waltair

At Lawson's B;y, the gears employed are shoreseines, boatseines, hooks and lines, surface g!llnets and bottom-set nylon nets. During the period 1970 to 1974, the estimated total annual landings by all gears were 654. 8, 62?.0', 577.<)8, 542.4 and 637.3 tonnes, respectively. The ca'iches by hooks and lines alone accounted for 50-60% of the tot.l landings during the period. Seasonal abundance of fish showed correlations with hydrological and planktological conditions and the food avalable in environment. Far pelagic fi&hes, high catch rates were obtained during Novem'ber to May and to a lesser extent during July-September. Prawns were caught in greater proportions by gillnets than by boat seines, the former being employed during May-September period. The adverse effects arising out of the introduction of bottom-set gillnets in the fishery are discussed

Not Available

Not AvailableThe earliest reference to the fecundity of the Indian mackerel was by Devanesan and John (1940) who estimated the number of ripe eggs in the mackerel ovary as 94,000. Subsequent work was directed mostly towards finding out the spawning behaviour of this fish, by the study of the intra-ovarian eggs. Pradhan (1956) indicated the possibility of the Indian mackerel spawning the eggs in successive batches over a prolonged period, like its Atlantic counter-part Scomber scombrus (L). Pradhan and Palekar (1956) described the maturity stages I to VII, based on the external appearance of the ovary, its size relative to the abdominal cavity, and the range of ova-diameter readings. However, they have not given any ova-diameter frequency polygons.Not Availabl

Not Available

Not AvailableWhile examining a sample of mackerel brought from UUal, a fishing village five miles from Mangalore, on 1st May 1961, a hermaphroditic gonad was observed in one specimen. The fish measured 221 mm, in total length and was normal to all outward appearance. Internally 'also, apart from this hermaphroditic gonad, no other abnormalities were noticed. Parasitic infection was not seen in the body cavity.Not Availabl

On the culture possibilities of Meretrix casta in Bhimunipatnam backwaters

It is observed that a rich natural bed of the clam Meretrix casta existed in the Bhimunipatnam backwaters, 32 kilometers north of Visakhapatnam. Some interesting points of observation on this bed are presented in this note