Hyachelia tortugae Barnard, 1967

Yabut, Mia G., Lazo-Wasem, Eric A., Sterling, Eleanor J. & Gómez, Andrés, 2014, New Records of Hyachelia tortugae Barnard, 1967, and H. lowryi Serejo and Sittrop, 2009 (Amphipoda: Gammaridea: Hyalidae), from Palmyra Atoll National Wildlife Refuge: Cooccurrence on Pacific Green Turtles (Chelonia mydas)., American Museum Novitates 2014 (3809), pp. 1-12 : 5

Hyachelia tortugae Barnard, 1967

Figures 3 , 4 , and 5A

Hyachelia tortugae is easily recognized based upon features of gnathopod 1 (males only) and pereopods 6 and 7. In males, article six of gnathopod 1 is very broad. The palm is sinuous and lined with stout robust setae. Additionally, four thick robust setae cover the posterodistal end of the sixth article. The dactyl is strikingly short, extending to only half the length of the palm. Gnathopod 2 (males), the palm is lined with robust setae and the proximoposterior corner protuberant. All the above characteristics can be seen through a microscope without dissection. However, the easiest way to recognize both males and females of this species is to examine the morphology of the sixth article of pereopods 6 and 7 (as well as pereopod 5, though this article is variable). If the distal margins of the sixth article of these pereopods are transverse, the specimen can be identified as H. tortugae ; these margins are lobed and lined with grasping robust setae. Another distinct characteristic of H. tortugae is the shape of the uropods. The outer ramus of uropod 1 is broad and spatulate and its inner ramus is completely bare. The inner ramus of uropod 2 lacks setae, and is distinctly lanceolate.

Figures

FIGURE 3. Hyachelia tortugae. AMNH 12533-11008-008, male 7.91 mm. A. Gnathopod 1 (outside lateral view). B. Gnathopod 2 (inside lateral view).

FIGURE 4. Hyachelia tortugae. AMNH 12533-11008-057, male 7.98 mm. A. Pereopod 6. B. Pereopod 7. C. Maxilliped. AMNH 12533-08013-277, female 5.30 mm. D. Uropod 1. E. Uropod 2.