Isaea Milne Edwards, 1830

Ariyama, Hiroyuki & Moritaki, Takeya, 2023, Two New Amphipods Associated with a Hermit Crab from the Kumano-nada, Central Japan (Crustacea: Amphipoda: Isaeidae, Stenothoidae), Records of the Australian Museum (Rec. Aust. Mus.) 75 (4), pp. 357-370 : 363

Genus Isaea Milne Edwards, 1830

[Japanese name: Yadokari-yokoebi-zoku, new]

Isaea Milne Edwards, 1830: 380 .— Chevreux & Fage, 1925: 328.— Lincoln, 1979: 496.— Barnard & Karaman, 1991 a: 197.— Myers & Lowry, 2003: 471.

Type species. Isaea montagui Milne Edwards, 1830 , monotypy.

Diagnosis. Antenna 1, peduncular article 3 0.7–1.1 times as long as article 1; accessory flagellum with 2–6 articles. Mouth parts ordinary. Coxae 1–4 long, strongly overlapping, progressively more elongate from 1 to 4, coxae 6, 7 much smaller than anterior coxae. Gnathopods subchelate, palm oblique; gnathopod 1, propodus longer than or subequal to carpus; gnathopod 2 much larger than 1, propodus dilated, longer than carpus. Pereopods prehensile, pereopods 3, 4 not glandular. Urosomites 1–3 free. Uropods 1–3 biramous, inner ramus of uropod 3 longer than or subequal to outer ramus. Telson fleshy, entire.

Included species. Isaea concinna Gurjanova, 1938 [Sea of Japan and Sea of Okhotsk ( Kudrjashov, 1972)]; I. concinnoides sp. nov. [Northwest Pacific]; I. elmhirsti Patience, 1909 [Northeast Atlantic]; and I. montagui Milne Edwards, 1830 [Northeast Atlantic and Mediterranean ( Lincoln, 1979)].

Remarks. The Isaeidae include only two genera: Isaea and Pagurisaea Moore, 1983 . Pagurisaea is distinguishable from Isaea in the glandular pereopods 3 and 4 and the uropod 3 with shortened inner ramus ( Moore, 1983).