External morphology and growth rate of white-eye bream Ballerus sapa (Cyprinidae, Teleostei) in a lowland dam reservoir on the lower Vistula River (Włocławek Reservoir, central Poland)

Title:

External morphology and growth rate of white-eye bream Ballerus sapa (Cyprinidae, Teleostei) in a lowland dam reservoir on the lower Vistula River (Włocławek Reservoir, central Poland)

Creator:

Kakareko, Tomasz, Kobak, Jarosław, Terlecki, Janusz, and Hadowski, Marcin

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:00191638-d369-10b6-606a-7b6fe7a03299
uuid:00191638-d369-10b6-606a-7b6fe7a03299

Subject:

feeding resources, mensural characters, meristic characters, and non-native fish

Type:

article and TEXT

Description:

To address the dearth of information on the biology of white-eye bream in its novel range of Europe, we examined the morphology and growth rate of specimens inhabiting a dam reservoir on the lower Vistula River and compared the results with those from other waters of native and non-native regions of this species. Altogether, 24 mensural and 15 qualitative characters of 93 individuals (45 females and 48 males) as well as age of 108 specimens were determined. Body length (l) of the fish ranged from 142 to 277 mm. To examine the patterns of relative growth, relationships between 21 mensural characters (raw data) and l were tested using a non-linear regression analysis: 5 characters were best described by a linear function, 5 by a power one, 10 by a quadratic and 1 by a split-linear regression. There were significant differences in morphometric characters among the studied population and those from the Zegrze Reservoir (Vistula River catchment) and the Dnieper River, suggesting substantial morphological plasticity of white-eye bream. Meristic characters (the basic characters are expressed by the following formula: l.l. 50-57; D II-III 7-8; A III-IV 36-43; P I-III 15-18; V I-III 8-9; C IV-VII 16-18; sp.br. 18-25; 5-5) showed considerable overlap with the literature data except the number of unbranched fin rays, which revealed greater variability. The growth rate of the white-bream from the Włocławek Reservoir was moderate in the first year of life, and then it was faster than in many waters from its native range. This marked increase of growth rate seemed to be site-specific rather than region-specific, and associated with particularly rich feeding resources (abundant bottom fauna) of the eutrophic and strongly flowing dam reservoir.

Language:

English

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/

Source:

Folia zoologica | 2008 Volume:57 | Number:4

Harvested from:

CDK

Metadata only:

false