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Background. The gudgeon is one of the most divergent fish species in Europe. Morphological variability related to sex, size, ecological characters, and geographical distribution are well documented in the literature. Apart from the only few data on the karyotype, chromosome banding patterns of this species have not been studied. Cytogenetic features are very useful tools in taxonomic descriptions of cyprinid species. The aim of this study was to describe and characterise the banding patterns of the gudgeon karyotype. Materials and Methods. Cytogenetic examinations of 15 specimens of gudgeon from the upper part of the Odra River, Poland, were carried out. Different chromosome banding techniques: Giemsa staining, C-banding, silver nitrate, chromomycin A3 and DAPI staining were used. Results. The karyotype of gudgeon consisted of 2n = 50 chromosomes, and NF = 98 chromosome arms. Ag-NORs were located on one submeta-subtelocentric chromosome pair and the size polymorphism of NORs was detected. The chromosome sites with G-C rich DNA on one submeta-subtelocentric chromosome pair and heterochromatin block in the centromeric regions were found. Low accumulation of A-T pair rich regions were indicated by DAPI staining. Conclusion. The presently described new chromosomal features of Gobio gobio substantially enhance our knowledge on the taxonomy of this species at cytogenetic level. Jointly with data on morphological- and genetic variability they could be used to determine the phylogeny of the genus Gobio and related species.
The ultrastructure of gamonts and sporulated oocysts of Goussia metchnikovi in the spleen of gudgeon, Gobio gobio from the river Lee, England is described. In developing microgamonts, small amylopectin granules were grouped centrally and nuclei were often arranged peripherally, close to the surface membrane. Nuclear chromatin condensed into peripheral dense portions that became the nuclei of flagellated microgametes, released to the parasitophorous vacuole. The cytoplasm of macrogametes had larger, scattered amylopectin granules, lipid globules and small electron-dense bodies, but no obvious wall forming bodies; peripheral vesicular structures with the appearance of mitochondria were also present and the parasitophorous vacuole contained flocculent material, but was otherwise free of structures. Sporulated oocysts contained four sporocysts and oocyst walls appeared to consist of a single membrane. Sporocyst walls showed a dehiscence suture, characteristic of the genus Goussia, which had filamentous extensions in places. The sporocyst wall comprised a dense inner layer and a thin outer layer with a fuzzy coat, separated by an electron lucent layer. Groups of oocysts were encapsulated by fibrous layers and inflammatory cells, and many sporocysts and their contained sporozoites showed evidence of elimination by the host.
Background. The gudgeon is a small fish of limited economic importance. Species of the genus Gobio bear a strong superficial resemblance to one each other, what has led to the misidentification of Central European gudgeons for many years. Consequently, accurate information about Polish populations of gudgeon is still scarce and more studies are needed to fill this gap. The purpose of the presently reported study is to describe the gudgeon on the basis of its morphological characters and to compare the results published by other authors. Materials and Methods. A total of 46 specimens of the gudgeon, Gobio gobio, were caught in the Zimnik Stream, the Skóra system, the Odra River drainage, western Poland, in October 2002. For each fish, 24 biometric features of the body and 20 features of the skull were measured. Selected meristic features (external and internal) were determined. Cephalic sensory canals were studied and their pores were counted. Results. The coefficient of variation for the body proportions of the sample of gudgeon from the Odra River drainage ranges from 1.7% to 7.2% and its principal features are as follows: D III 7–9; A III 6–7; P I 11–15; V I 6–8; l.l. 37–41. Two rows of pharyngeal teeth are present, most frequently, in 2.5–5.2 pattern. The total number of vertebrae ranges from 46 to 48 (mean 47.38). Conclusion. This study shows that the sample analyzed has the shortest head length in relation to other measurements and the body length, as compared to other populations from Polish rivers. The majority of values of meristic features do not differ significantly from those found in literature. The presently provided internal meristic and osteological features of gudgeon are among very few such data available.
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