Nihonotrypaea makarovi Marin, 2013

First zoea (Fig. 1)

Material examined. TL = 3.66 ± 0.04 mm; CL = 1.51 ± 0.02 mm; N = 10.

Carapace (Fig. 1A, B). Longer than wide; frontal margin with pair of short antennal spines, anteroventral margins serrated; rostral spine straight, long, pointed, shorter than carapace, covered with spinules in distal part; eyes sessile; cervical groove not visible, linea thalassinica absent.

Antennule (Fig. 1C). Elongated, uniramous, unsegmented, with 3 terminal aesthetascs of different length, 3 terminal simple setae of different length and a long densely plumose subterminal seta on inner margin.

Antenna (Fig. 1D). Peduncle with a distal serrated spine near the base of scaphocerite; endopod unsegmented, shorter than half of exopod, with 2 long terminal plumose setae; scaphocerite with a distal spine, 7–8 inner plumose setae and 1 outer short sparsely plumose seta.

Mandible (Fig. 1E).Without palp.

Maxillule (Fig. 1F). Coxal endite with 6–7 plumodenticulate setae; basial endite with 2 marginal plumodenticulate cuspidate setae and 3 submarginal plumodenticulate setae; endopod incompletely 2-segmented, with 3, 2+4 plumodenticulate setae.

Maxilla (Fig. 1G). Coxal and basial endites distinctly bilobed; coxal endite with 11–13+3–4 plumodenticulate setae; basial endite with 7+5–6 plumodenticulate setae; endopod unsegmented, with 3–4+2+2+5 plumodenticulate setae; scaphognathite with 5 marginal densely plumose setae (narrow proximal lobe bearing with very long seta).

First maxilliped (Fig. 1H). Coxa nearly equal basis, with 7 plumodenticulate setae; basis with 10–11 plumodenticulate setae; endopod slightly shorter than exopod, 4-segmented, with 10 plumodenticulate and 1 outer plumose setae arranged 3, 2, 2, 3+1; exopod unsegmented, with 4 terminal plumose natatory setae.

Second maxilliped (Fig. 1I). Coxa shorter than basis, with 1 plumodenticulate seta; basis with 5 plumodenticulate setae; endopod shorter than exopod, 4-segmented, with 10 plumodenticulate and 1 outer plumose setae arranged 2, 2, 2, 4+1; exopod as in the first maxilliped.

Third maxilliped (Fig. 1J). Coxa shorter than basis, without setae; basis with 1–2 plumodenticulate setae of different length; endopod half the length of exopod, not clearly segmented, with 4–5 plumodenticulate and 1 outer plumose setae arranged 1–2, 3+1; exopod unsegmented, with 5 terminal plumose natatory setae.

Pereiopods. Absent.

Pleon (Fig. 1A, B). Five pleonites, pleonite 2 with a long posterodorsal spine, pleonites 3–5 with comb-like denticulated ridges.

Pleopods. Absent.

Telson (Fig. 1K). Triangular, longer than wide, with central spine fused with telson; posterior margin with 7+1+7 processes: outermost spine-like serrated seta, plumose thalassinidean hair near base of the process 3 and 5 long plumodenticulate setae; anal spine absent.

Uropod. Absent.

Colour. A pair of large orange chromatophores on the ventral margins of carapace.