Salgado-Maldonado Guillermo, Aguilar-Aguilar Rogelio, Cabañas-Carranza Guillermina
Instituto de Biología, Universidad Nacional Autónoma de México, Apartado Postal 70-153, CP 04510, México D.F., Mexico.
Syst Parasitol. 2005 Mar;60(3):205-9. doi: 10.1007/s11230-004-6349-3.
Atactorhynchus duranguensis n. sp. (Acanthocephala: Atactorhynchinae) is described from the intestine of Cyprinodon meeki Miller, an endemic freshwater fish from a far-inland locality of Mexico. Diagnostic features include: body small, stout, ventrally curved; small cylindrical proboscis armed with 16 alternating vertical rows of four or five hooks; anterior two or three hooks conspicuous, stout and larger than other hooks, and have large, rod-shaped roots with a markedly and abruptly enlarged base; three posterior hooks of each row are smaller and rootless; single-walled proboscis receptacle; lemnisci equal in length, elongate and robust; and cement gland syncytial, larger than testis. The new species is smaller than A. verecundus Chandler, 1935, the only previously described species in the genus. The shape of the proboscis of the new species is strikingly different from that of A. verecundus, which is widest at the apex. Likewise, the greatest width of the trunk of the new species is in about the middle, differing from that of A. verecundus where the trunk is widest posteriorly. The new species also can be distinguished from A. verecundus because of its much smaller hook lengths and slightly smaller proboscis. In addition, the proportion of large apical proboscis hooks in relation to the small basal hooks is different: the basal hooks of A. verecundus are about half the size of the anterior hooks and but only about a quarter of the size in A. duranguensis. Unlike A. verecundus, the base of the roots are markedly and abruptly enlarged in the new species. Finally, the eggs of the new species are smaller (23-27 x 8-10 microm) than those of A. verecundus (27-30 x 12-13 microm).
杜兰戈无吻棘头虫新种（棘头虫纲：无吻棘头虫亚科）采自墨西哥内陆偏远地区特有的淡水鱼类——米氏食蚊鱼的肠道。诊断特征包括：虫体小而粗壮，腹面弯曲；小圆柱形吻部具16排交替排列的四五列钩；前两三个钩明显，粗壮且大于其他钩，具大的棒状根，基部明显且突然膨大；每排后三个钩较小且无根；单壁吻囊；颈叶长度相等，细长且粗壮；粘腺为合胞体，大于睾丸。新物种比1935年描述的该属唯一物种——羞怯无吻棘头虫小。新物种吻部的形状与羞怯无吻棘头虫显著不同，后者在顶端最宽。同样，新物种躯干的最宽处约在中部，不同于羞怯无吻棘头虫，其躯干在后部最宽。新物种还可因其钩长度小得多且吻部稍小而与羞怯无吻棘头虫区分开来。此外，大的顶端吻钩与小的基部钩的比例不同：羞怯无吻棘头虫的基部钩约为前钩大小一半，但在杜兰戈无吻棘头虫中仅约为四分之一大小。与羞怯无吻棘头虫不同，新物种根的基部明显且突然膨大。最后，新物种的卵（23 - 27×8 - 10微米）比羞怯无吻棘头虫的卵（27 - 30×12 - 13微米）小。
