Liomera tristis (Dana, 1852)

Al-Haj, Ahmed E., Kumar, A. A. J., El-Sherbiny, Mohsen M., Al-Sofyani, Abdulmohsin, Crosby, Michael P. & Al-Aidaroos, Ali M., 2019, Descriptions of the first zoeas of ten xanthid crabs (Crustacea: Decapoda Xanthoidea) from the Gulf of Aqaba, Red Sea, Zootaxa 4686 (3), pp. 301-345 : 324-331

Liomera tristis (Dana, 1852)

( Figs. 22–24 )

Zoea I. Size (mean ± sd): CW = 0.7 ± 0.01 mm; CL = 0.79 ± 0.2 mm; TT = 1.53 ± 0.03 mm.

Cephalothorax ( Fig. 22a ). Dorsal spine long, straight, curved distally; rostral spine straight, shorter than protopod of antenna; lateral spines straight, short, smooth; one pair of posterodorsal setae; eyes sessile.

Antennule ( Fig. 22b ). Uniramous; endopod absent; exopod unsegmented with 4 broad, aesthetascs, one slender terminal seta.

Antenna ( Fig. 22c ). Protopodal process, longer than rostral spine; endopod present as minute spine; exopod robust, 24% length of protopod with 3 setae.

Maxillule ( Fig. 23a ). Coxal endite with 7 plumodenticulate setae; basial endite with 5 (2 cuspidate, 3 plumodenticulate) setae; endopod 2-segmented, proximal segment with one simple seta, distal segment with 2+4 setae; exopod setae absent.

Maxilla ( Fig. 23b ). Coxal endite bilobed with 4+4 plumodenticulate setae; basial endite with 5+4 setate; endopod unsegmented, bilobed with 3+5 plumodenticulate setae; exopod (scaphognathite) margin with 4 plumose setae, one stout distal process.

First maxilliped ( Fig. 23c ). Basial endite with 10 medial simple setae arranged 2+2+3+3; endopod 5-segmented with 3,2,1,2,1+4 setae respectively; exopod 2-segmented, distal segment with 4 terminal plumose natatory setae.

Second maxilliped ( Fig. 23d ). Basial endite with 4 medial simple setae arranged 1+1+1+1; endopod 3-segmented with 1,1 (plumose), 5 setae. Exopod 2-segmented, distal segment with 4 terminal plumose natatory setae.

Pleon ( Fig. 24a ). Five somites; somite 2 with one pair of dorsolateral processes directed anteriorly; somite 3 with one pair of dorsolateral processes directed posteriorly; somite 1 with rounded posterolateral process; somites 2–5 with short posterolateral spinous processes; somite 1 without setae; somites 2–5 each with one pair of posterodorsal setae.

Telson ( Fig. 24b ). Each fork gradually curved distally with 2 lateral and 1 medial spines; inner margin with 3 pairs of stout spinulate setae.

Figures

FIGURE 22. Liomera tristis Dana, 1852, zoea I; a) anterior view of cephalothorax; b) antennule; c) antenna.

FIGURE 23. Liomera tristis Dana, 1852, zoea I; a) maxillule; b) maxilla; c) first maxilliped; d) second maxilliped.

FIGURE 24. Liomera tristis Dana, 1852, zoea I; a) dorsal view of pleon; b) dorsal view of fork of telson.