Showing papers by "Annamalai University published in 1974"

A karyotype study of some teleosts from portonovo waters

Abstract: 1. The present report embodies the results of a study on the karyotypes of 16 teleost species belonging to 15 families and 7 orders,viz., Anguilliformes (1 sp.), Cypriniformes (1 sp.), Siluriformes (1 sp.), Synbranchiformes (1 sp.), Scorpaeniformes (2 spp.), Perciformes (9 spp.) and Tetradontiformes (1 sp.). 2. The diploid chromosome numbers in the 16 species presently studied ranges from 40 to 62. 3. The size of the chromosomes ranges from 0·83 to 5·30µ. 4. No heteromorphic pair or pairs of chromosomes are discernible in any of them: further, a study of the karyotypes in both the sexes ofMystus gulio, Etroplus suratensis, E. maculatus, Mugil cephalus andAnabas testudineus failed to reveal the occurrence of heteromorphism, if any, in them. 5. Based on the available morphological and cytological information, the systematic position and species interrelationships have also been discussed.

Arylsulfatase activity in marine sediments

Abstract: Arylsulfatase activity and arylsulfatase-producing bacteria were estimated in sediment samples collected from 3 different biotopes: marine, estuarine, and mangrove. No direct relationship could be established between activity and the number of bacteria at any station. In general, clayey sediments always harboured more arylsulfatase producers than sandy sediments, irrespective of salinity variations. Of the 3 biotopes investigated, the mangrove area exhibited maximum activity. The enzyme showed two pH optima, one at 6.2, the other at 9.0. The optimum substrate concentration was 12x10-4M. Higher substrate concentrations tended to inhibit arylsulfatase activity. The recovery of added phenolphthalein was maximum only at pH 6.2; KCN, Na2So4, and KH2Po4 inhibited enzyme activity by 65.5, 46.8 and 37.5%, respectively. More than one type of arylsulfatase may be present in marine sediments; further studies on the role of arylsulfatases are required, since arylsulfatases have been reported to bear on the formation and hardening of exoskeletons in marine forms.

Studies on the seasonal abundance of the fish eggs and larvae of porto novo waters

Abstract: The seasonal abundance and distribution of fish eggs and larvae in the coastal waters of Porto Novo based on the daily data collected for a period of 2 years, 1970-71 and 1971-72, are given. Eggs of 18 species and larvae of 28 species of fishes have been recorded from the 5-10 fathom line (Station 1) and Vellar river mouth (Station 2). The year 1971-72 appeared to be more favourable for fish eggs and larvae than 1970-71. During monsoon months, lowest number of eggs and highest number of larvae were encountered in Station 2. But in the postmonsoon period the reverse was true. In Station 1, however, large number of eggs occurred throughout the year compared to Station 2. It is therefore indicated that probably the Vellar estuary also serves as a good nursery ground for many of the fishes in Porto Novo waters.

Effect of pituitary extracts on the hypophysial gonadotrophes and its relation to the spermatogenesis in Rana hexadactyla Lesson.

Abstract: Pituitary extracts from 560 mature Rana hexadactyla of both sexes from winter and summer seasons were collected locally and were injected into frogs from summer and winter months. The adenohypophysial gonadotrophes were studied from normal animals and from the animals injected with pituitary extracts. The pituitary cell types changed in experimental frogs in comparison to the corresponding cells of normal animals. An attempt has been made to correlate the changes of gonadotrophes with changes in spermatogenetic proliferation as reported earlier (Kasinathan and Basu, '72).

Amino acid composition and carbohydrate units in the adductor muscle ofAmussium pleuronectes andMexetrix meretrix

Abstract: Gelatins from the adductor muscles of two species of bivalve molluscsAmussium pleuronectes andMeretrix meretrix were prepared and the amino acid composition and the carbohydrates associated with the gelatins were estimated.