Ferreira Maryke L, Smit Nico J, Grutter Alexandra S, Davies Angela J
Department of Zoology, University of Johannesburg, Auckland Park, South Africa.
J Parasitol. 2009 Oct;95(5):1066-75. doi: 10.1645/GE-1920.1. Epub 2009 Apr 6.
During March 2002 and November 2005, teleost fishes were collected at Lizard Island, Great Barrier Reef (GBR), Australia. Gnathiid isopod juveniles were allowed to detach from these host fishes and were maintained in fresh seawater until they molted into adults. Adult males emerged 5 days post-detachment (d.p.d.) and females 10 d.p.d. of juveniles from host fish. The adults and juveniles were identified as new to science and described as Gnathia aureamaculosa n. sp. The species description is based on brightfield and scanning electron microscopy observations primarily of males, since the taxonomy of gnathiids is based on male morphology. This species has been widely employed in various studies on the Great Barrier Reef, from its involvement in feeding patterns in reef fish to its role in transmitting blood parasites, and has been referred to as Gnathia sp. A. Distinctive features of the male include gold-spotted pigmentation on the dorsal pereon of live specimens, a cephalosome with a conical superior fronto-lateral process, an inferior and conical medio-frontal process, and mandibles, each with an armed carina and an internal lobe. The female is characterized by its broad, rounded shape and cephalosome setae. The mandible of the third stage juvenile has 2 small teeth on the tip and 7 large teeth on the mesial margin. Differential pigmentation occurs in live male and female third-stage juveniles; females have greenish-yellow spots distributed over the pereon and males have white blotches and light brown and yellow spots on the pereon.
2002年3月至2005年11月期间，在澳大利亚大堡礁蜥蜴岛采集了硬骨鱼类。让寄生性等足类幼体从这些宿主鱼类身上脱离，并饲养在新鲜海水中，直至它们蜕变成成虫。成年雄性在脱离宿主鱼后的第5天（d.p.d.）出现，成年雌性在脱离宿主鱼后的第10天出现。这些成虫和幼体被鉴定为科学上新发现的物种，并被描述为黄斑颚虱新种（Gnathia aureamaculosa n. sp.）。物种描述主要基于对雄性的明场和扫描电子显微镜观察，因为颚虱的分类学是基于雄性形态。该物种已广泛应用于大堡礁的各种研究中，从其在珊瑚礁鱼类摄食模式中的作用到其在传播血液寄生虫方面的作用，并且被称为Gnathia sp. A。雄性的显著特征包括活体标本背侧躯干部位的金色斑点色素沉着、一个具有圆锥形上额外侧突起的头节、一个圆锥形的下额中突起以及每个都带有武装隆线和内叶的下颌。雌性的特征在于其宽阔、圆形的形状和头节刚毛。第三阶段幼体的下颌在尖端有2颗小齿，在内缘有7颗大齿。活体雄性和雌性第三阶段幼体存在色素沉着差异；雌性在躯干部位分布有黄绿色斑点，而雄性在躯干部位有白色斑点以及浅棕色和黄色斑点。
