958 resultados para Morphological descriptors


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Genetic and morphological characters of four hatchery population (Shambhuganj, Brahmaputra, Anudan and Bhai-Bhai) of Thai pangas, Pangasius hypophthalmus in Mymensingh region of Bangladesh was studied using morphological characters and allozyme markers from 29 November 2001 to 29 November 2002. A total of 14 morphometric and 6 meristic characters were verified, among which 3 morphometric (BDA, PELFL and HW) and 2 meristic characters (AFR, CFR) of Anudan hatchery population were found to be significantly higher (p>0.001) than those of the other three hatchery populations. Brahmaputra hatchery population was also significantly higher in two meristic characters (PCFR and CFR). For allozyme electrophoresis nine enzyme markers were used viz.: Esr-1*, G3pdh-2*, Gpi-1*, Gpi-2*, Ldh-1*, Ldh-2*, Mdh-1*, Mdh-2* and Pgm* where three loci (Esr-1*, Gpi-2* and Pgm*) were polymorphic (p>0.95) in Anudan and Brahmaputra hatchery populations. The mean proportion of polymorphic loci per population was higher (33.3%) in Brahmaputra and Anudan hatchery populations. Also the expected heterozygosity levels were 0.149 and 0.177 in Brahmaputra and Anudan hatchery populations, respectively. Based on Nei's (1972) genetic distances, the UPGMA dendrogram grouped the populations into two clusters. The Brahmaputra and Anudan populations are in one group; Shambhuganj, and Bhai-Bhai populations are in the second group. High genetic variation in Thai pangas was observed in the Brahmaputra and Anudan hatchery populations and less variation in the other two hatchery populations.

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Climbing perch locally known as koi (Anabas testudineus) is a popular food fish in our country. Thai climbing perch was introduced in Bangladesh from Thailand. To explore the variation in growth performance and orphological features of local and Thai climbing perch a study was undertaken. The highest gain in length, weight and SGR were found in Thai koi 12.23±0.38 cm, 55.83±0.53 g and 7.92±0.11 %/day respectively. Fourteen morphometric characters were studied where eleven (TL, SL, HL, HBD, LBD, DFL, PECFL, PELFL, AFL, UJL and LJL) showed significant difference (p<0.01) in Thai koi from the local ones. Of the meristic characters no. of dorsal fin rays (hard), anal fin rays (hard), caudal fin rays and scale along lateral line (upper and lower) as recorded from the Thai koi were significantly higher (p<0.01) than that of the local koi. The no. of dorsal fin rays (soft) in Thai koi were also significantly higher (p<0.05) from that of local koi. The number of vertebra were also variable in local and Thai climbing perch (25 in case of local koi and 26 in case of Thai koi). Hence, the results obtained form the present study satisfy the characteristics of A. testudineus which reveals that both the local and Thai koi belongs to the same species. Growth performance of Thai koi was better compared to local koi reared in same conditions.

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TSV-DM, a basic metalloproteinase with a molecular weight of 110 kDa, was purified from Trimeresurus stejnegeri venom. TSV-DM degraded the A alpha chain of fibrinogen more rapidly than the B beta chain in a dose dependent manner. The cDNA of TSV-DM encode

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The morphological characteristics and overlap of fish community in Vamanapuram River have been studied in detail. In the 12 study sites, 19 fish species were encountered. Based on the body shape, four different types are apparent. The elongate bodied fishes (RBD<1.5) like Hemiramphus xanthopterus and Xenentodon cancila are grouped under one category. The deep bodied fishes (RBD>3.5) like Puntius filamentosus, P. ticto, P. vittatus, P. melanampyx, P. sarana, Etroplus maculatus and E. suratensis come under a separate category. Fishes with round to square cross section like Garra mullya and Glossogobius giuris form a separate group. All the other species are grouped as generalized bodied fishes. The morphological overlap studied for the Vamanapuram fish community showed that out of 190 combinations, 30 combinations have high overlaps (≥ 67). P. melanampyx has maximum number (6) of high overlaps. Puntius spp., which constituted 49.5% of the total population, have a mean morphological overlap of 52%. The morphological overlap of fish species in relation to the trophic structure is discussed in detail.

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Two aerobic, gram-negative asporogenous, red-pigmented, rod-shaped bacterial strains were isolated from oil sardine (Sardinella longiceps). Their morphological, biochemical and growth characteristics are reported. The pigment was identified to be a prodigiosene. The strains were found to resemble Serratia plymuthica. Effect of temperature and certain carbohydrates on pigmentation was also studied. Iron was found to inhibit pigmentation, and mannitol or sorbitol removed such inhibition.

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We sequenced partial mitochondrial 16S ribosomal DNA (16S rDNA) of 18 firefly species from Southwest of China. Combined with homologous sequences previously reported, phylogenetic trees including Japanese, Korean and Chinese species were reconstructed by

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The order Zoantharia (Zoanthids) is one of the most neglected orders of cnidarians in the Persian Gulf. The present study aims to investigate the biodiversity of this order with morphological and molecular examination in the Persian Gulf. For this purpose, 123 colonies of zoanthids with variety of shape and colors have been collected from intertidal and shallow water zone of four islands, i. e. Hengam, Qeshm, Larak and Hormoz. After sampling, morphological characteristics of each specimen were recorded based on in situ photographs. Then DNA was extracted using the cetyl trimethyl ammonium bromide (CTAB) method. Both mitochondrial 16S ribosomal DNA (mt 16S rDNA) and cytochrome oxidase subunit I (COI) gene fragments were amplified and sequenced. The results of preliminary morphological identification integrated with two mitochondrial markers sequencing demonstrated the presence of five different species in this region; Zoanthus sansibaricus, Palythoa mutuki, Palythoa cf. mutuki, Palythoa tuberculosa and Neozoanthus persicus?. Although at first sight, morphological properties were not successful to delineate zoanthid species, they become reliable criteria to identify and delineate species in field studies after molecular identification.

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Gymnodiptychus integrigymnatus is a critically endangered species endemic to the Gaoligongshan Mountains. It was thought to be only distributed in several headwater-streams of the Longchuanjiang River (west slope of the Gaoligongshan Mountains, belonging to the Irrawaddy River drainage). In recent years, dozens of G. integrigymnatus specimens have been collected in some streams on the east slope of the Gaoligongshan Mountains (the Salween drainage). We performed a morphological and genetic analyses (based on cytochrome b and D-loop) of the newly discovered populations of G. integrigymnatus to determine whether the degree of separation of these populations warrants species status. Our analysis from the cytochrome b gene revealed that nine individuals from the Irrawaddy drainage area and seven individuals from the Salween drainage area each have only one unique haplotype. The genetic distance between the two haplotypes is 1.97%. Our phylogenetic analysis revealed that G. integrigymnatus is closely related to highly specialized schizothoracine fishes. Analysis from the mitochondrial control region revealed that G. integrigymnatus has relatively high genetic diversity (pi was 0.00891 and h was 0.8714), and individuals from different river drainages do not share the same haplotypes. The AMOVA results indicated 87.27% genetic variability between the Salween and Irrawaddy populations. Phylogenetic trees show two major geographic groups corresponding to the river systems. We recommend that G. integrigymnatus should be considered as a high priority for protected species status in the Gaoligongshan Mountains National Nature Reserve, and that the area of the Gaoligongshan Mountains National Nature Reserve should be expanded to cover the entire distribution of G. integrigymnatus. Populations of G. integrigymnatus from different river systems should be treated as evolutionarily significant units.

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水蛇亚科属于游蛇科,包含10个属。其中7个属为单型属。选取水蛇亚科14个形态学特征进行支序分析,并利用计算机软件Hennig86对水蛇亚科中8个属之间的系统发育关系进行初步探讨,结果显示水蛇亚科分为两支Gerarda和Fordonia两个属构成姊妹群,Cerberus、Erpeton和Homalopsis三个属也构成单系群,与Vorisetal(2002)的分子系统树相同,但Cantoria属的地位则与Vorisetal(2002)的明显不同。