Sex ratio in oil sardine

The studies on the sex-ratios of oil sardine spread over eleven seasons indicated that the females have a higher rate of growth, hence their preponderance in the various length groups of the population. The stabilisation of the oil sardine fishery in the recent years appears to have a close relation with the dominance of females in the O-year class which supports the fisher

Sea erosion at Baitkhol (Karwar) and its effect on indigenous fishing

The waves not only smashed the parapet wall bordering the western side of the road but also inundated the area which caused breaches in small patches at several points. In this process, many small huts of fishermen on the other side of the road were destroyed

The oil sardine fishery in the Mangalore zone during the seasons 1963—64 and 1967—68

The oil sardine fishery in the Mangalore zone showed an upward trend from 1963-64 to 1966-67 when the catches increased seven-fold from 52 to 386 tonnes, which was followed by a slight decline to 243 tonnes in 1967-68. Among the gears operated for the oil sardine fishery, the highest catch-per-unit-efFort values were obtained for the cast net, chala bale and rampant. The best catches of oil sardine were obtained during September-December period when temperature and salinity values ranged 25.5 to 28.6''C and 28.98 to 34.36 %, respectively. The length frequency studies indicate that the oil sardine attains a size of about 100-110 mm during the first year, 150-160 mm during the second year and 175-180 mm during the third year of its appearance. The fishery during the various years was supported by difierent year classes. One and two-year olds dominated in 1963-64, 1966-67 and 1967-68 and one-year olds in 1964-65. In 1965-66, one-year olds formed the mainstay of the fishery, although the two-year olds also contributed from December onwards. O-year class was seen entering the fishery during the months of August and September in 1964-65, 1965-66 and 1966-67, as also in October and again in January and February during 1967-68. Two or more broods have been observed to enter the fishery during certain years. Judged from the rate of growth and the size attained by the smaller size groups composing the O-year class, the interval between the entries of various broods has been observed to vary from one to three months. The estimated average rate of decrease diu'ing the five-year period worked out to 0.72, the instantaneous rate of mortality being 1.27

Marine Fish Calendar. 10. Karwar

Karwar is situated almost at the northernmost (Lat. 14°50' N and Long. 74°03' E) tip of the Karnataka coast. It is the district headquarters of Uttar Kannada. The coastline extending from Majali in the north to Kasaragod in the south was once famous for rampart (shore seine) fishing till the advent of this decade. This part of the coast was called the 'mackerel coast'. The fishing in the Karwar area is based by and large on the purse seiners. As such the fish calendar is prepared on the fish landings of this gear only and the data covered is from 1981 through 1985

Electrophoretic studies on serum proteins of oil sardine (Sardinella longiceps) and Mackerel (Rastrelliger kanagurta)

Oil sardine blood tests against human typing sera indicated A - positive, A - negative and B - negative. The blood of mackerel is antigenically negative both for A and B. Elect rophoretic studies on serum proteins revealed the existence of genetically different groups of oil sardine and mackerel on the south-west coast of India

Electrophoretic characteristics of oil sardine (Sardinella longiceps) and mackerel (Rastrelliger kanagurta) eye lens proteins

Electrophoresis of eye lens protei ns of oil sardine and mackerel showed separation of proteins into three and four components, indicating the heterogenous nature of the population

Sex ratio and maturity stages of the oil sardine, Sardinella longiceps Val., from the Mangalore zone

Determination of sex ratio of the oil sardine during the period of 7 years, 196C—67, showed that there is not much difference in the ratio of the two sexes during the fishing seasons and the apparent variation which is seen from month to month is probably due to inadequacy in sampling. Disparity in sex ratio in one-year class in most years and equality of both the sexes among the two-year old fishes have been recorded. The occurrence of oil sardine at different stages of maturity has been determined. Active spawning seems to occur from June to September

Food of the oil sardine taken by bottom nets And surface gill net in the mangalore area

The food of the oil sardine, Sardinella longiceps Val., caught off Mangalore by gear operating in the upper layers and close to the sea floor was studied. Fish obtained from the surface gill net showed poor feeding and the food consisted mainly of Coscinodiscus, a typical diatom of the upper layers. On the other hand, fish from bottom gill nets and trawl nets had gorged stomachs and the food item comprised mainly, in some cases exclusively, either Pleurosigma or Ornithocercus which are typical bottom-dwelling forms. It is suggested that the oil sardine occasionally resorts to a demersal habitat

Occurrence of small sized seer fishes S. Guttatus and S. Commerson at Karwar (Karnataka)

Small sized s. Guttatus and s. Commerson were obsereved at karwar.they could be identified based on some external features. The second dorsal fin in s. Commerson is tinged as brightly yellow as its caudal fin, whereas in the other species it is lacking. In s. Guttatus the teeth on the lower half of the jaw are of villiform type and are more in numbers whereas in the other there are 6-7 prominent teeth pointing backwar

The food of small-sized oil sardine of the Mangalore area

The food of oil sardine ranging 40-79 mm in length consisted of diatoms, dinoflagellates and copepods. There seems to be no consistency in regard to various food items in different size groups. Studies have also shown the absence of selective feeding in small oil sardine