Mimonectes, 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 : 19-20

Key to the species of the genus Mimonectes

1. Gnathopods 1 & 2; propodus with distinct projection above and below, or just below, insertion of dactyl................. 2

- Gnathopods 1 & 2; propodus without distal projections, or projections minute...................................... 4

2. Gnathopods 1 & 2; propodus without antero-distal projection but with distinct postero-distal projection below insertion of dactyl................................................................................. M. alexanderi sp. nov.

- Gnathopods 1 & 2; propodus with distinct antero-distal projection above insertion of dactyl and shorter postero-distal projection below dactyl...................................................................................... 3

3. Gnathopods 1 & 2; propodus relatively narrow, width about 0.3x length (or less). Pereopod 3 slightly shorter than P4. Pereopods 5–7 with propodus slightly shorter than carpus.................................... M. gaussi (Woltereck, 1904)

- Gnathopods 1 & 2; propodus relatively broad, width about 0.4x length. Pereopod 3 slightly longer than, or sub-equal in length to, P4. Pereopods 5–7 with propodus slightly longer than carpus (especially P7 of males).... M. diomedeae ( Woltereck, 1909)

4. Pereopods 3–7 with relatively broad articles; merus relatively short, only slightly longer than ischium......................................................................................... M. spandlii Stephensen & Pirlot, 1931

- Pereopods 3–7 with relatively slender articles; merus length more than twice ischium................................ 5

5. Gnathopod 1; propodus with very small distal projection on either side of dactyl. Gnathopod 2 simple, relatively slender......................................................................... M. stephenseni ( Pirlot, 1929) comb. nov.

- Gnathopod 1; propodus without distal projections. Gnathopod 2 simple, or marginally to strongly sub-chelate, with relatively broad, rarely slender articles............................................................................. 6

6. Gnathopods 1 & 2; margins of propodus evenly convex, with numerous fine setae; dactyl relatively weak, short, length less than 0.3x propodus................................................................ M. loveni Bovallius, 1885

- Gnathopods 1 & 2; margins of propodus not especially convex; posterior margin without, or with slight, or distinct postero-distal excavation, with groups of strong setae; dactyl relatively strong, longer than 0.3x propodus........................ 7

7. Pereopod 3 distinctly longer than P4–6. Males with thick, opaque cuticle; pereonites with furrows, decreasing in prominence from pereonites 1–7.................................................................................... 8

- Pereopod 3 similar in length to P4 & 5 (sometimes also P6). Males with relatively thin, translucent cuticle (like females); pereonites without furrows.................................................................................. 9

8. Gnathopod 2; posterior margin of propodus with weak setae distally; dactyl relatively slender, not pressed against propodus. Pereopod 4 slightly shorter than P5, or sub-equal in length. Males; head with short lateral lobe at base of A1; pereonites with relatively deep furrows, especially for pereonites 1–4; telson length about one-third peduncle of U3.... M. colemani sp. nov.

- Gnathopod 2; posterior margin of propodus with pairs of strong setae; dactyl pressed against medial surface of propodus. Pereopod 4 slightly longer than P5. Males; head without lobe at base of A1; pereonites with slight furrows, barely noticeable on pereonites 5–7; telson length about half peduncle of U3................................... M. neosphaericus sp. nov.

9. Gnathopod 2 simple................................................. M. birsteini ( Vinogradov, 1956) comb. nov.

- Gnathopod 2 chelate.................................................................................. 10

10. Gnathopod 2; propodus sometimes expanded distally, with distinct postero-distal excavation. Pereopods 3–7 with relatively weak, almost semi-colon-like dactyls. Pereopods 3–5; propodus shorter than carpus, tapering distally................................................................................................ M. sphaericus Bovallius, 1885

- Gnathopod 2; propodus narrowing distally, with moderate postero-distal excavation. Pereopods 3–7 with relatively robust, curved dactyls. Pereopods 3–5; propodus equal in length to carpus, evenly broad............................................................................................. M. vinogradovi ( Shih & Hendrycks, 1996) comb. nov.