Montes Martin Miguel, Castro-Romero Raúl, Bovcon Nelson, Ostoich Nicolas, Valerga Emilia, Theiller Mariela, Balcazar Darío
Centro de Estudios Parasitológicos y Vectores (CEPAVE), Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de La Plata (CONICET-UNLP), Boulevard 120 s/n e/ 60 y 64, CP 1900, La Plata, Buenos Aires, Argentina.
Departamento de Ciencias Acuáticas y Ambientales, Facultad de Ciencias del Mar y Recursos Naturales, Universidad de Antofagasta, Casilla 170, Antofagasta, Chile.
Syst Parasitol. 2025 Sep 17;102(6):56. doi: 10.1007/s11230-025-10251-x.
A new species, Pseudocharopinus tenshken n. sp., is described and illustrated as a parasite of juvenile Squalus acanthias from Argentine waters in the South Atlantic. Although morphologically similar to Pseudocharopinus bicaudatus, a species widely distributed on the same host, distinct morphological differences are evident. The new species differs from P. bicaudatus in its dorsal shield, which is more elongated and has more developed sclerites. Additionally, the cephalothorax of the new species reaches 82% of the trunk length, whereas it is shorter in P. bicaudatus. In contrast, the maxilla in P. bicaudatus extends up to 65% of the trunk length, while in P. tenshken n. sp., it reaches 76% of the trunk length. These morphological distinctions are supported by a genetic divergence of 17% from P. bicaudatus. In the COI phylogenetic tree, a strongly supported clade is observed, consisting of (Pseudocharopinus malleus (P. bicaudatus + Lernaeopoda bivia)). Then, Salmincola spp. appears in a clade with low support, followed by Pseudocharopinus pillai. Later, another strongly supported clade includes (Pseudocharopinus tenshken n. sp. (Brianella corniger + Pseudocharopinus pteromylaei)). Based on our results, the genus Pseudocharopinus should be considered non-monophyletic. These findings suggest that at least two independent Lernaeopodid infection events occurred in chondrichthyans.
描述并图示了一个新物种，即来自南大西洋阿根廷海域的棘鲨幼体的寄生虫——坦什肯拟沙蚕新种（Pseudocharopinus tenshken n. sp.）。尽管在形态上与广泛分布于同一宿主的双尾拟沙蚕（Pseudocharopinus bicaudatus）相似，但明显存在明显的形态差异。新物种与双尾拟沙蚕的区别在于其背盾，背盾更长且骨片更发达。此外，新物种的头胸部长度达到躯干长度的82%，而双尾拟沙蚕的头胸部较短。相比之下，双尾拟沙蚕的上颌延伸至躯干长度的65%，而在坦什肯拟沙蚕新种中，上颌达到躯干长度的76%。这些形态差异得到了与双尾拟沙蚕17%的遗传差异的支持。在细胞色素氧化酶亚基I（COI）系统发育树中，观察到一个得到有力支持的分支，由（锤形拟沙蚕（双尾拟沙蚕 + 双叉锚头鱼蚤））组成。然后，鲑虱属（Salmincola spp.）出现在一个支持度较低的分支中，接着是皮莱拟沙蚕（Pseudocharopinus pillai）。后来，另一个得到有力支持的分支包括（坦什肯拟沙蚕新种（角形布氏鱼虱（Brianella corniger） + 翼形拟沙蚕（Pseudocharopinus pteromylaei）））。基于我们的结果，拟沙蚕属应被视为非单系的。这些发现表明，至少有两次独立的锚头鱼蚤科感染事件发生在软骨鱼类中。
