Data from: Morphometric discrimination of two allozymically diagnosed sibling species of the Echinorhynchus gadi Zoega in Muller complex (Acanthocephala) in the North Sea.

Allozyme electrophoresis was used to detect biological species of the E. gadi complex from gadids from the northern North Sea. A fixed difference at one of nine enzyme loci surveyed confirmed the existence of two reproductively isolated, sympatric species. Mixed infections of two E. gadi spp. (termed A and B) were observed in Gadus morhua and Pollachius virens. E. gadi sp. B was also found in Melanogrammus aeglefinus and Merlangius merlangus. The presence of gravid females of E. gadi spp. A and B in the same host species, P. virens, and sometimes in the same host individual, indicates that neither differential host-specificity nor seasonal differences in mating time are responsible for their reproductive isolation. Morphological study of probosces from electrophoretically identified specimens demonstrated that the two species can be discriminated in graphical and cluster analyses of hook morphometrics. E. gadi sp. I (of Vainola etal., 1994) and E. gadi sp. A are probably conspecific.

本研究采用同工酶电泳（Allozyme electrophoresis）技术，对北海北部海域鳕科鱼类体内的E. gadi复合类群进行物种鉴定。在所检测的9个酶位点中，有1个位点存在固定差异，证实存在两个生殖隔离的同域物种。在大西洋鳕（Gadus morhua）与绿青鳕（Pollachius virens）体内观测到两种被分别记为A和B的E. gadi物种的混合感染。E. gadi sp. B还见于黑线鳕（Melanogrammus aeglefinus）与牙鳕（Merlangius merlangus）体内。在同一宿主绿青鳕（P. virens），甚至同一宿主个体中，均发现了携带受精卵的E. gadi sp. A与sp. B雌虫，这表明宿主特异性差异与交配时间的季节差异均并非二者生殖隔离的成因。对经电泳鉴定的标本的吻突进行形态学研究显示，通过对钩形度量值的图形分析与聚类分析，可有效区分这两个物种。Vainola等人1994年报道的E. gadi sp. I与E. gadi sp. A大概率为同一物种。