Karyotype characterization of the endemic piscine leech from Lake Baikal with vindication of Baicalobdella cottidarum Dogiel, 1957 (Piscicolidae, Hirudinea) (original) (raw)
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A representative of the Lake Baikal leech fauna was studied karyologically for the first time. Air-dried cytolo-gical preparations were made from the testisacs of Baicalobdella torquata (Grube, 1871), an endemic species of this lake. The samples were obtained from the population inhabiting the littoral zone of Southern Baikal. Chromosome numbers were determined from both mitotic and meiotic stages of spermatogenesis using "shak-ing-blotting" technique. Diploid and haploid chromosome sets demonstrate 2n=32 and n=16, respectively. This result is similar to that of closely related species Piscicola geometra (Linnaeus, 1758) and confirms systematic position of this species within the family Piscicolidae. Four size groups of chromosomes were detected in B. torquata karyogram, including marker chromosomes. Ring-shaped and cruciform elements were registered within the chromosome set of this leech.
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.
Genetics and molecular research : GMR, 2005
A cytogenetic study was performed on the large pimelodid species Steindachneridion scripta (Siluriformes, Sorubiminae) from the Paraná River basin (Brazil). Chromosome preparations were obtained avoiding sacrifice of the specimens, by means of lymphocyte culture, and several staining and chromosome banding techniques were applied. The karyotype consisted of 56 chromosomes, 24 metacentrics, 20 submetacentrics, 4 subtelocentrics, and 8 acrocentrics (fundamental number = 104). The first pair of acrocentric chromosomes (pair 25) consistently had a decondensed secondary constriction; the C-banding pattern of some chromosomes allows them to be considered cytogenetic markers (i.e., pairs 1, 3, 4, 6, 7, 9, 13, 23, and 24). G-banding and restriction enzymes provided patterns that helped improve chromosome pairing. This is the first report on a Neotropical pimelodid species of economic interest using several cytogenetic techniques and providing an integral karyotypic characterization.
Karyotype of the Baikal amphipod Polyacanthisca calceolata Bazikalova, 1937,(Crustacea, Amphipoda)
The karyotype of the endemic Baikal amphipod Poly-acanthiska calceolata Bazikalova, 1937 was analysed for the first time. A diploid number (2n=52) and general chromosome morphology (with a median centromere) are typical amongst Gammaridea. A peculiar feature of the karyotype was its pronounced symmetry caused by the presence of metacentric (equal-armed) chromo-somes insignificantly varying in size (from 5 to 8 μm). Sex chromosomes have not been distinguished. Super-numerary B chromosomes were regularly found in the metaphase plates of embryos P. calceolata, and may serve as an adaptive mechanism of this species to per-form migrations to areas of gas hydrate seeps.
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.
A checklist of chromosome numbers and karyotypes of Amazonian freshwater fishes
José das Neves FALCAO (2) RÉSUMÉ CATALOGUE DES NOMBRES DE CHROMOSOMES ET CARYOTYPES DES POISSONS DU BASSIN AMAZONIEN Une liste des nombres de chromosomes de 211 espèces de poissons du bassin amazonien est présenfée. Ces espèces, appartenant à 5 ordres, sont caractérisées par une grande variabilité du nombre de chromosomes (2n = 22 à 2n = 134), par la présence de chromosomes sexuels et de polymorphisme chromosomique chez certaines espèces, et enfin par une grande spécificité des bandes C et des sites des régions de l'organisafeur du nucléole. MOTS CLÉS : Chromosomes-Poissons-Eaux douces-Bassin amazonien. ABSTRACT A CHECKLIST OF CHROMOSOME NUMBERS AND KARYOTYPES OF AMAZONIAN FRESHWATER FISHES A checklist of chromosome numbers of Amazonian freshlvater fishes is presented. 211 nominal species belonging fo 5 orders have had their haploidldiploid number listed. These species are characterized by a high karyotypic diversity including a wide chromosome number range (2n=22 to 2n=134), d ff i erent sex chromosomal mechanisms, chromosomal polymorphisms and nearly always a species-specific pattern of C-banding and nucleolar organizer regions .
Data on karyotype of fishes in Nigeria is limited. In this study, chromosome analysis of Clarias anguillaris (Linnaeus, 1758), C. pachynema (Boulenger, 1903), C. gariepinus (Burchell, 1862) C. camerunensis (Lonnberg, 1895), C. jaensis (Boulenger, 1909) and C. macromystax (Gunther, 1864) from South-West Nigeria was carried out using the kidney cells. C. anguillaris have variable 2n = 48 and 56. The spread with 2n = 48 comprised 27 metacentric, 10 submetacentric, 3 subtelocentric and 8 telocentric chromosomes; while the spread with 2n = 56, which is the modal diploid number, comprised 33 metacentric, 12 submetacentric, 2 subtelocentric and 9 telocentric chromosomes. C. pachynema with 2n = 66 comprised 30 metacentric, 10 submetacentric, 16 subtelocentric and 10 telocentric chromosomes. The 2n = 56 for C. gariepinus comprised 25 metacentric, 14 submetacentric, 14 subtelocentric and 3 telocentric chromosomes; while same diploid number for C. camerunensis included 22 metacentric, 20 submetacentric, 9 subtelocentric and 5 telocentric chromosomes. C. jaensis had a 2n = 54, comprising 22 metacentric, 12 submetacentric, 5 subtelocentric and 15 telocentric chromosomes, while the 2n = 49 for C. macromystax comprised 27 metacentric 10 submetacentric, 11 subtelocentric and 1 telocentric chromosomes. Idiograms were prepared for each species based on the chromosome measurements. Several reasons were adduced for the karyotypic variability in C. anguillaris. This study is of importance in the evolution, classification and taxonomy of Clarias species and also in monitoring aquatic toxicity.
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.