Comparative fishing experiments with two trawl designs used in the inshore waters off Kakinada (Andhra Pradesh)

The importance of small trawlers for the economic exploitation of the inshore demersal fisheries is well recognized and accordingly mechanized boats of sizes 30' and 32' fitted with engines of h.p. ranging from 30 to 45 came into existence particularly at Kakinada. The need to work out the most suitable trawling gear for these classes of boats becomes imperative and as an appurtenance to this, comparative fishing experiments were attempted with different trawls. In the present communication certain observations made on the relative catch efficiency of two different trawl nets used in combination with two different shaped otter boards are given.

Comparative studies on the canning properties of pomfrets and hilsa

Fresh silver pomfret, black pomfret and hilsa were canned at absolutely fresh and iced conditions and the qualities of the final products were studied comparatively in relation to the initial quality of the raw materials. Under identical conditions a maximum quantity of cook-drip and nitrogen contents were found to be lost in black pomfret and minimum in hilsa. Silver pomfret and black pomfret iced for 3 days gave fairly good products on canning while hilsa came out only as a satisfactory product on canning after the same ice storage period of the raw material.

Comparative account of growth rate of body parts with total length in adult Puntius sarana (Ham.)

The present study on growth rate of different body parts in relation to total length, in the male and female Puntius sarana (Ham.) did not show any significant heterogeneity except in snout length (p.01). The growth rate of snout length was found to be higher in females (b=0.0377) than in males (b=0.0266). Since the growth rate of most of the body parts was found to be homogeneous in both the sexes, the common regression co-efficient "b" was calculated on pooled data to represent the growth rate of different body parts against total length, the linearity of regression lines indicated isometric growth.

Estimation of ploidy and hybridization status by erythrocyte and nucleus size analysis in carps

The present experiment was designed to observe whether the nuclear volume and area are affected by the ploidy and hybrid status of the individual. Polyploidy was induced by heat shock treatment given at 44 ± 0.5°C for 30 seconds and 45 seconds which was found to be most effective (64.7%) for induction of triploidy in Cyprinus carpio. Cell and nuclear volume and cell and nuclear area varied significantly in triploid fishes as compared to those of controls. Triploid fishes showed significantly higher growth compared to diploid counterparts. It was also observed that catla x rohu hybrid and its parents showed significant difference in the nuclear volume and area of their erythrocytes. Except nuclear volume, all the parameters were significantly different between catla and catla x rohu hybrid. The hybrids showed a closer relationship with catla as compared to rohu.

Comparative account of growth rate of body parts with total length in Rita pavimentata (Gunther)

The paper deals with sex-wise growth rate of different body parts in relation to total length in Rita paviinentata (Gunther). Growth rates calculated on pooled data by using the common regression coefficient 'b' reveals isometric and homogeneous nature in sexes.

Comparative efficiencies of mechanized fishing crafts introduced in India

India started mechanization of fishing craft in early 1950. The traditional craft was subjected to technical scrutiny and some of them mechanized with good results. However, due to limitations inherent in the traditional craft, it was found necessary to develop new series of crafts suitable for the operation of modern fishing gears in areas hitherto unexplored. The impetus given to the development of infrastructure like freezing, canning and ice plants, and quickly expanding export market, increased the demand for marine products, hence craft for immediate, as well as long-term needs had to be introduced. In this article the author discusses design of fishing vessels, information from experience used in development of vessels, designs of distant water vessels, productivity studies, income and expenditure, economic values, production cost, and productivity.

A comparative study of the morphometrics and the proximate composition of two edible molluscs Crassostrea cuculata (Born) and Perna perna (L.)

The morphometrics and the bio-chemical characteristics of Crassostrea cuculata and Perna perna were studied. In the oyster, the length was found to be positively correlated with breadth and total body weight. There was also a positive relationship between the total body weight and the total muscle weight. In the mytilid the total body weight was positively correlated with length and total muscle weight. The muscle weight was also found to be highly correlated with the length. In both animals the relationship between the length and the total body weight was curvilinear. In the oyster, the protein content was found to increase with the total body weight and the total muscle weight. In the mytilid the protein content increased not only with the total body weight but also with the length. In both animals, the relative content of protein is higher than that of carbohydrates, lipids and ash.

A COMPARATIVE-STUDY OF KARYOTYPES OF MUNTJACS BY CHROMOSOME PAINTING

We have used a combination of chromosome sorting, degenerate oligonucleotide-primed polymerase chain reaction (DOP-PCR), chromosome painting and digital image capturing and processing techniques for comparative chromosome analysis of members of the genus Muntiacus. Chromosome-specific ''paints'' from a female Indian muntjac were hybridised to the metaphase chromosomes of the Gongshan, Black, and Chinese muntjac by both single and three colour chromosome painting. Karyotypes and idiograms for the Indian, Gongshan, Black and Chinese muntjac were constructed, based on enhanced 4', 6-diamidino-2-phenylindole (DAPI) banding patterns. The hybridisation signal for each paint was assigned to specific bands or chromosomes for all of the above muntjac species. The interspecific chromosomal homology was demonstrated by the use of both enhanced DAPI banding and comparative chromosome painting. These results provide direct molecular cytogenetic evidence for the tandem fusion theory of the chromosome evolution of muntjac species.

Evolution of the black muntjac (Muntiacus crinifrons) karyotype revealed by comparative chromosome painting

The black muntjac (Muntiacus crinifrons) has an unusual karyotype of 2n = 8 in females and 2n = 9 in males. We have studied the evolution of this karyotype by hybridising chromosome-specific paints derived from flow-sorted chromosomes of the Chinese muntjac (M. reevesi, 2n = 46) to chromosomes of the black muntjac. The hybridisation pattern allowed us to infer chromosomal homologies between these two species. Tandem and centromeric fusions, reciprocal translocations, and insertions are involved in the reduction of the diploid number from 2n = 46 to 2n = 8, 9. The painting patterns further show complex chromosomal rearrangements in the male black muntjac which involve more than half the karyotype, including both sex chromosomes. Since early meiosis is reported to be normal without any visible inversion loops of the synaptonemal complex, the observed chromosomal rearrangements would lead to heterosynapsis and, therefore, leave a large fraction of the male black muntjac karyotype balanced between the two sexes.

Comparative molecular cytogenetic studies in the order Carnivora: mapping chromosomal rearrangements onto the phylogenetic tree

We have made a set of chromosome-specific painting probes for the American mink by degenerate oligonucleotide primed-PCR (DOP-PCR) amplification of flow-sorted chromosomes. The painting probes were used to delimit homologous chromosomal segments among human, red fox, dog, cat and eight species of the family Mustelidae, including the European mink, steppe and forest polecats, least weasel, mountain weasel, Japanese sable, striped polecat, and badger. Based on the results of chromosome painting and G-banding, comparative maps between these species have been established. The integrated map demonstrates a high level of karyotype conservation among mustelid species. Comparative analysis of the conserved chromosomal segments among mustelids and outgroup species revealed 18 putative ancestral autosomal segments that probably represent the ancestral chromosomes, or chromosome arms, in the karyotype of the most recent ancestor of the family Mustelidae. The proposed 2n = 38 ancestral Mustelidae karyotype appears to have been retained in some modern mustelids, e.g., Martes, Lutra, ktonyx, and Vormela. The derivation of the mustelid karyotypes from the putative ancestral state resulted from centric fusions, fissions, the addition of heterochromatic arms, and occasional pericentric inversions. Our results confirm many of the evolutionary conclusions suggested by other data and strengthen the topology of the carnivore phylogenetic tree through the inclusion of genome-wide chromosome rearrangements. Copyright (C) 2002 S. KargerAG, Basel.

Comparative map between the domestic pig and dog

Cross-species chromosome painting with probes derived from flow-sorted dog and human chromosomes was used to construct a high-resolution comparative map for the pig. In total 98 conserved autosomal segments between pig and dog were detected by probes specific for the 38 autosomes and X Chromosome of the dog. Further integration of our results with the published human-dog and cat-dog comparative maps, and with data from comparative gene mapping, increases the resolution of the current pig-human comparative map. It allows for the conserved syntenies detected in the pig, human, and cat to be aligned against the putative ancestral karyotype of eutherian mammals and for the history of karyotype evolution of the pig lineage to be reconstructed. Fifteen fusions, 17 fissions, and 23 inversions are required to convert the ancestral mammalian karyotype into the extant karyotype of the pig.

Cross-species chromosome painting in the golden mole and elephant-shrew: support for the mammalian clades Afrotheria and Afroinsectiphillia but not Afroinsectivora

Cross-species painting (fluorescence in situ hybridization) with 23 human (Homo sapiens (HSA)) chromosome-specific painting probes (HSA 1-22 and the X) was used to delimit regions of homology on the chromosomes of the golden mole (Ghrysochloris asiaticus) and elephant-shrew (Elephantulus rupestris). A cladistic interpretation of our data provides evidence of two unique associations, HSA 1/19p and 5/21/3, that support Afrotheria. The recognition of HSA 5/3/21 expands on the 3/21 synteny originally designated as an ancestral state for all eutherians. We have identified one adjacent segment combination (HSA2/8p/4) that is supportive of Afroinsectiphillia (aardvark, golden mole, elephant-shrew). Two segmental combinations (HSA 10q/17 and HSA 3/20) unite the aardvark and elephant-shrews as sister taxa. The finding that segmental syntenies in evolutionarily distant taxa can improve phylogenetic resolution suggests that they may be useful for testing sequence-based phylogenies of the early eutherian mammals. They may even suggest clades that sequence trees are not recovering with any consistency and thus encourage the search for additional rare genomic changes among afrotheres.

Phylogenomics of several deer species revealed by comparative chromosome painting with Chinese muntjac paints

A set of Chinese muntjac (Muntiacus reevesi) chromosome-specific paints has been hybridized onto the metaphases of sika deer (Cervus nippon, CNI, 2n = 66), red deer (Cervus elaphus, CEL, 2n = 62) and tufted deer (Elaphodus cephalophus, ECE, 2n = 47). Thir

High-density comparative BAC mapping in the black muntjac (Muntiacus crinifrons): Molecular cytogenetic dissection of the origin of MCR 1p+4 in the X1X2Y1Y2Y3 sex chromosome system

The black muntjac (Muntiacus crinifrons, 2n = 8 female/9 male) is a critically endangered mammalian species that is confined to a narrow region of southeastern China. Male black muntjacs have an astonishing X1X2Y1Y2Y3 sex chromosome system, unparalleled i

Comparative genome maps of the pangolin, hedgehog, sloth, anteater and human revealed by cross-species chromosome painting: further insight into the ancestral karyotype and genome evolution of eutherian mammals

To better understand the evolution of genome organization of eutherian mammals, comparative maps based on chromosome painting have been constructed between human and representative species of three eutherian orders: Xenarthra, Pholidota, and Eulipotyphla,