The first cytogenetic report of the endemic fish leech Baicalobdella torquata (Hirudinida, Piscicolidae) from Lake Baikal (original) (raw)
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Archives of Biological Sciences, 2015
In this paper, we present for the first time data on karyotype analysis of leeches of the genus Baicalobdella (Piscicolidae) parasitizing Lake Baikal endemic cottoid fishes. Both mitotic and meiotic chromosomes are described. Leech testisacs were processed by a ?shaking-blotting? technique, and chromosomal preparations were stained with water-based fuchsine. Diploid and haploid chromosome sets demonstrated 2n=34 and n=17, respectively, with maximal chromosome length of 1.5-3.0 ?m. Comparative karyotype analysis of two ecological forms of Baicalobdella leeches revealed differences in chromosome numbers and its morphology. Previously studied Baicalobdella torquata (Grube, 1871) parasitizing Baikal amphipods had smaller diploid and haploid sets (2n=32, n=16). In addition to numerical superiority, differing patterns of chromosome size gradation and presence of satellite elements were found in the karyotype of piscine Baicalobdella leeches. This confirms the systematic position of the Ba...
An investigation of the karyotypes of two species of the genus Brachymystax (B. lenok and B. tumensis) has been done for the Russia Primorye rivers running to the East Sea basin, and others belonging to Amur basin. Based on the analysis of two species chromosome characteristics, combined with original and literary data, four cytotypes have been described. One of these cytotypes (Cytotype I: 2n= =90, NF= =110-118) was the most common. This common cytotype belongs to B. tumensis from the rivers of the East Sea basin and B. lenok from the rivers of the Amur basin, i.e. extends to the zones of allopatry. In the rivers of the Amur river basin, in the zone of the sympatric habitat of two species, each taxon has karyotypes with different chromosome numbers, B. tumensis (2n= =92) and B. lenok (2n= =90). Because of the ability to determine a number of the chromosome arms for these two species, additional cytotype have been identified for B. tumensis: Cytotype II with 2n= =92, NF= =110-124 in the rivers basins of the Yellow sea and Amur river and for B. lenok three cytotypes: Cytotype I: 2n= =90, NF= =110 in the Amur river basin; Cytotype III with 2n= =90, NF= =106-126 in the Amur river basin and Cytotypes IV with 2n= =92, NF= =102 in the Baikal lake.
Chromosomal Analysis on A Few Species of Ornamental Fishes
Karyology deals with the chromosome morphology and behaviour during cell cycle. Every organism is characterized by its own specific chromosomes both in number and morphology. Generally fish have been the subject of investigations for their systematic, mutagenesis and culture. The cytogenetic and karyomorphological studies would are aid in the improvement species including ornamental species. Currently, aquarium fish being ornamental gain new importance as a small scale industry product and the ability as in and established to be a balanced entry with great marketability. The present study has been carried out to provide some karyological information on the economically important ornamental fish species. The method of Kligerman and Bloom (1997) was standardized for the chromosome preparations. Chromosome spreads were made for gill, and kidney tissue. Well spread metaphase spreads were photographed from gill tissues. The diploid chromosome numbers were determined for the 8 ornamental fish species. Gymnocorymbus ternetzi 2n = 48; Hemigrammus armstrongi 2n =50; Lobeo bicolor 2n=54; Puntius gelius 2n =52; Betta aplendens 2n = 50; Colisa lalia 2n=68; Trichogaster leeri 2n =66 and Trichogaster trichopterus 2n=72. And it is provided the information on the variations in size, number, karyomorphological or structural variation and staining have been discussed in view of adaptive and evolutionary significance.
2011
The aim of the present study was to characterize chromosomal differences between two populations separated in the past for a water divide. Processes of differentiation have been identifi ed in the species studied, being justifi ed by the separation of streams from past for a water divide. Karyotypic data were presented for Astyanax altiparanae, Geophagus brasiliensis and Gymnotus carapo populations of two different river systems of the upper Parana: ribeirão do Pântano (Tietê basin) and ribeirão do Feijão (Mogi Guaçu basin) in the São Carlos region, state of São Paulo. The Astyanax altiparanae, presented a diploid number of 2n=50 chromosomes. The Geophagus brasiliensis diploid numbers was 2n=48 chromosomes and Gymnotus carapo a diploid number of 2n=54 chromosomes. An analysis was made of constitutive heterochromatin by C-banding, detection of nucleolar organizer regions and the technique of Hybridization in situ Fluorescent with probes 18S rDNA and 5S rDNA. These results indicate that the species analysed showed differences of karyotype, showing that each population follows its own evolution, as a result of a restrictive process of gene fl ow.
Comparative Cytogenetic Study Among Three Fish Species: An Analysis from a Water Divide Region
Publicatio UEPG: Ciencias Biologicas e da Saude, 2011
The aim of the present study was to characterize chromosomal differences between two populations separated in the past for a water divide. Processes of differentiation have been identifi ed in the species studied, being justifi ed by the separation of streams from past for a water divide. Karyotypic data were presented for Astyanax altiparanae, Geophagus brasiliensis and Gymnotus carapo populations of two different river systems of the upper Parana: ribeirão do Pântano (Tietê basin) and ribeirão do Feijão (Mogi Guaçu basin) in the São Carlos region, state of São Paulo. The Astyanax altiparanae, presented a diploid number of 2n=50 chromosomes. The Geophagus brasiliensis diploid numbers was 2n=48 chromosomes and Gymnotus carapo a diploid number of 2n=54 chromosomes. An analysis was made of constitutive heterochromatin by C-banding, detection of nucleolar organizer regions and the technique of Hybridization in situ Fluorescent with probes 18S rDNA and 5S rDNA. These results indicate that the species analysed showed differences of karyotype, showing that each population follows its own evolution, as a result of a restrictive process of gene fl ow.
Chromosomal studies of three vulnerable marine fishes from west coast of India
2011
Cytogenetic profiling was carried out in three vulnerable marine ornamental fishes, namely Thalassoma lunare, Zanclus cornutl~s and Arius subrostratus, using silver nitrate, chromoycin A3 CMA 3 staining and C-banding techniques to study the variation in localization of NORs and C-bands. Karyotype analyses of these species revealed a diploid chromosome number of 48, all acrocentrics, in T. lunare and Z. cornutus. In A. subrostratus, however, the diploid chromosome number was found to be 58 consisting of 22 metacentric, 16 submetacentric, 10 subtelocentric and 10 telocentric chromosomes with fundamental arm number of 96. The silver stained NORs were observed on 3 pairs of chromosomes in T. lunare, whereas other two species possessed NOR on single pair of chromosome. Within the species, there was complete concordance in number and position of NORs as detected by AgN0 3 and CMA 3 staining. Prominent constitutive heterochromatic bands were detected on 4, 2 and 3 pairs of chromosomes, respectively, in T. lunare, Z. cornutus and A. subrostratus. There was variation found in the number and position on NORs and C-bands among these species, which could be used as species-specific markers. This study describes for the first time the cytogenetic profiling in Z. cornutus and A. subrostratus.
Comparative Cytogenetics, 2013
Hemisorubim platyrhynchos is a medium-to large-sized pimelodid catfish distributed along several river basins of the Neotropical Region, noteworthy for representing an important fishery source. In this work, H. platyrhynchos from three isolated populations were cytogenetically analyzed. The karyotype shows a diploid number of 2n=56 chromosomes comprising 22m, 16sm, 10st, 8a (FN=104). NORs detected by AgNO 3 were located in the terminal regions of the short arm of a st chromosome pair, as confirmed by CMA 3 and FISH using an 18S rDNA probe. C-banding revealed a small amount of heterochromatin in chromosomes, including the NORs, and one biarmed pair that showed conspicuous positive bands on both arms. This fact was also evidenced when using other banding techniques, such as RE (AluI), and indicates that this pair constitutes a species-specific cytogenetic marker.
An overview of marine fish cytogenetics
Marine Genetics, 2000
The number of cytogenetic studies of marine fish has increased in recent years. Fish groups, such as Perciformes, which comprises many of the extant marine teleosts of economic importance, show little divergence in chromosome number and most species display a diploid number of 48 acrocentric chromosomes. In the Serranidae, Sparidae, Sciaenidae (Perciformes) and Mugilidae (Mugiliformes) small chromosome variations are restricted to subtle heterochromatin or nucleolar organizer region (NOR) modifications. There appears to exist a strict relationship between both absence of geographic barriers throughout the marine environment and high mobility of these animals (eggs, larvae, or adults), with a rarity of chromosome rearrangement at the macrostructural level. Moreover, a cellular homeostasis might also be important to karyotype maintenance among these fishes, limiting changes in the chromosome complement to cryptic chromosome rearrangements. Other groups, such as Blenniidae, Gobiidae and Scorpaenidae, for instance, show more extensive chromosome diversity, which is probably related to limited mobility. Numerical and structural chromosome polymorphisms and several sexual chromosome systems are recurrent among these fishes. A wide karyotypic diversification also characterizes the Tetraodontiformes, an interesting fish group with peculiar morphological, physiological and ecological characteristics.