MIMONECTIDAE Bovallius, 1885

Zeidler, Wolfgang, 2012, A review of the hyperiidean amphipod families Mimonectidae and Proscinidae (Crustacea: Amphipoda: Hyperiidea: Scinoidea) 3533, Zootaxa 3533, pp. 1-74 : 17-18

Family MIMONECTIDAE Bovallius, 1885

Diagnosis. Sexually mature specimens with body length 7–30 mm. Head rarely as long as first pereonite; without rostrum. Eyes very small, or absent. Sexual dimorphism of some species pronounced, with pereon of sexually mature females spherically inflated. Pereon of males only marginally inflated, or slender. Pereonites all separate. Coxae separate from pereonites. Antennae 1 with stout, setose callynophore; with three short terminal articles, sometimes with few large aesthetascs and one long terminal seta; peduncle two-articulate, rarely three-articulate ( Pseudomimonectes ); rarely as long as head and pereon combined. Antennae 2 reduced in females and immature males; sometimes as long as 0.7x A 1 in mature males, or also reduced to few articles. Mandibles with welldeveloped lacinia mobilis (left), slightly narrower or wider than incisor; most inferior tooth of incisor strongest and separated from other teeth by large gap, or similar to other teeth and not separated by gap ( Cheloscina ). Maxillae 1 with broad palp, armed with few setae distally; outer lobe usually with broad distal margin, armed with 4–5 strong setae distally; inner lobe usually with broad distal margin, armed with numerous fine setae. Maxillae 2 with relatively slender lobes of similar length; both armed with 2–3 strong setae distally. Maxilliped with oval, or semicircular, outer lobes; inner lobes short, rarely exceeding half length outer lobes, sometimes fused proximally. Gnathopods simple or weakly sub-chelate; distal corners of propodus sometimes projected alongside dactyl; propodus sometimes with postero-distal excavation. Pereopods simple; dactyls never retractile or hooded. Urosomite 2–3 with partial suture ventrally. Uropoda slender, with articulated rami. Telson length 0.3–0.7x peduncle of U3, triangular with rounded or pointed apex. Gills on pereonites 2–6. Oostegites on pereonites 2–5.

Three genera: Cheloscina , Mimonectes and Pseudomimonectes .

Remarks. The family Mimonectidae was established by Bovallius (1885) to encompass three new species in his new genus Mimonectes ; M. loveni , M. sphaericus and M. steenstrupi (= Archaeoscina steenstrupi ). Subsequently, Stebbing (1904) added Parascina and Woltereck (1904a) added Sphaeromimonectes . Later, Woltereck (1906) concluded that Parascina represented a juvenile or male form of his genus, and this is the currently accepted view, and has been confirmed by the examination of the genotype, P. fowleri Stebbing, 1904 . The differences between Mimonectes and Sphaeromimonectes , as defined by Woltereck (1904 a, 1927), are based primarily on errors in the description of A. steenstrupi by Bovallius (1885), a species which has since been placed in its own family, Archaeoscinidae . Thus, Stephensen and Pirlot (1931), in a revision of the genera of the family, synonymised the latter with the former and included Parascina in the synonymy.

Only one other genus, Pseudomimonectes , has since been added to the family ( Vinogradov 1960). It is very similar to Mimonectes , but differs mainly in having mandibles with a one-articulate palp, and first antennae with a three-articulate peduncle.

Cheloscina is here included in this family because it possesses characters consistent with the family, similar to Mimonectes , and the status of the family Proscinidae cannot be maintained.

The family is distinguished from Scinidae by the structure of pereopod 5, in that the inner ramus of the uropoda is freely articulated with the peduncle, and by the inner lobes of the maxilliped, that are well-developed, and not fused. It is most readily distinguished from Mimoscinidae fam. nov. and Microscinidae fam. nov. by having pereopoda without retractile dactyls.