Epixanthus frontalis (H. Milne Edwards, 1834 )

Clark, Paul F. & Paula, José, 2003, Descriptions Of Ten Xanthoidean (Crustacea: Decapoda: Brachyura) First Stage Zoeas From Inhaca Island, Mozambique, Raffles Bulletin of Zoology 51 (2), pp. 323-378 : 329

Epixanthus frontalis (H. Milne Edwards, 1834)

( Figs. 5-8 )

Larval description. – Carapace ( Fig. 5a ): dorsal spine long and curved distally, longer than rostral spine; rostral spine approximately equal in length to antennal protopod and without spinulation distally; lateral spines present and straight; 1 pair of posterodorsal setae; ventral margin without setae; eyes sessile.

Antennule ( Fig. 5b ): uniramous, endopod absent; exopod unsegmented with 2 broad, long, 1 long slender, 2 shorter, slender terminal aesthetascs of unequal length and 1 short terminal seta.

Antenna ( Fig. 5c ): protopodal process distally, bilaterally spinulate, approximately equal in length to rostral spine; endopod absent; exopod ca. 41% length of protopod, possessing 3 (1 long subterminal, 2 unequal terminal) setae with small spinules at base.

Mandible: endopod palp absent.

Maxillule ( Fig. 6a ): epipod seta absent; coxal endite with 7 setae; basial endite with 5 setal processes and 2 small teeth; endopod 2-segmented, proximal segment with 1 seta; distal segment with 6 (2 subterminal, 4 terminal) setae; exopod seta absent.

Maxilla ( Fig. 6b ): coxal endite bilobed with 5+4 setae; basial endite bilobed with 5+4 setae; endopod bilobed, with 3+5 (2 subterminal, 3 terminal) setae; exopod (scaphognathite) margin with 4 setae and 1 long distal stout process.

First maxilliped ( Fig. 7a ): coxal segment with 1 seta; basis with 10 setae arranged 2,2,3,3; endopod 5-segmented with 3,2,1,2,5 (1 subterminal, 4 terminal) setae respectively; exopod 2-segmented, distal segment with 4 long terminal plumose natatory setae.

Second maxilliped ( Fig. 7b ): coxa without setae; basis with 4 setae arranged 1,1,1,1; endopod 3-segmented, with 1,1,6 (3 subterminal, 3 terminal) setae respectively; exopod 2- segmented, distal segment with 4 long terminal plumose natatory setae.

Third maxilliped: absent.

Pereiopods: absent.

Abdomen ( Figs. 8a, b ): 5 somites; somite 2 with 1 pair of dorsolateral processes directed anteriorly; somite 3 with 1 pair of dorsolateral processes directed ventrally; somites 1-2 with rounded posterolateral processes and 3-5 with short rounded posterolateral processes; somite 1 without setae; somites 2-5 with 1 pair of posterodorsal setae; pleopod buds absent.

Telson ( Figs. 6c , 8a, b ): each fork long, gradually curved distally; 1 large and 1 small lateral spine; 1 large dorsal medial spine; posterior margin with 3 pairs of stout spinulate setae.

Figures

Fig. 5. Epixanthus frontalis (H. Milne Edwards, 1834) first stage zoea; a) anterior view of carapace; b) antennule; c) antenna.

Fig. 6. Epixanthus frontalis (H. Milne Edwards, 1834) first stage zoea; a) maxillule; b) maxilla; c) telson.

Fig. 7. Epixanthus frontalis (H. Milne Edwards, 1834) first stage zoea; a) first maxilliped; b) second maxilliped.

Fig. 8. Epixanthus frontalis (H. Milne Edwards, 1834) first stage zoea; a) dorsal view of abdomen; b) lateral view of abdomen.