Scyllarides squammosus (H. Milne Edwards, 1837) Nisto

Material examined: Nisto, NSMT-Cr 30950, BL = 39 mm, CL = 14.5 mm, CW = 17 mm, TL = 9 mm.

Description: Carapace (Fig. 3A, 3B): Wider than longer (CW/CL 1.17) with maximum width in the middle; surface with few tubercules, entirely furnished with fine setae; anterior margin smooth, a prominent horn present at both angles; lateral margin possessing a distinct post-cervical incision, with 8 (right) to 9 (left) anterolateral and 14 (right) to 12 (left) post-lateral teeth; rostral short with blunt end; 2 prominent tubercules and 1 small tubercule on the inner and posterior edges of orbits; gastric tooth possessing 2 prominent tubercles anteriorly and 4 small setae posteriorly; cardiac tooth bearing 2 rows of prominent tubercules anteriorly and 2 rows of small setae posteriorly, cardiac ridge with small setae; 10 small setae (8 each on the right and left sides, 2 in the middle) present along the post-cervical groove; 10 small setae in a row along post-lateral teeth; 5 small setae present at middle of posterior margin.

Antennule (Fig. 4A): Peduncle 3-segmented with flagellated distal end; proximal segment bearing dense long setae on ventral side; second segment possessing small setae scattered; third segment almost naked; accessory flagellum 18-articulated as long as the primary flagellum; primary flagellum thicker than accessory flagellum, 15-articulated, group of aesthetascs present on articles 5–12.

Antenna (Fig. 3A): 4-segmented, biramous, broad, flat; proximal segment inverted triangle, anterior margin with a ridge at middle; second segment with serrated lateral margin, prominent horn at anterolateral angle, a small notch on anteromedial margin, 2 small teeth on medial margin; third segment bearing a prominent tooth on anteromedial angle; distal segment surrounded with finely serrated margins.

Mandible (Fig. 4B): Poorly developed, slightly asymmetrical; palp present.

Maxillule (Fig. 4 C): Uniramous; poorly developed; basal endite with 5 small tubercules on anterior margin; coxal endite unarmed on anterior margin, bearing 3 small setae on basal part.

Maxilla (Fig. 4D): Flattened; endopod slightly differentiated with 8 setae and 3 small spines on the medial margin; endites differentiated, 4 (2+2) and 7 (5+2) setae on anterior ends of coxal and basal endites, 1 and 2 setae present on the inner proximal parts of coxal and basal endites, respectively; hair-like setae lining the outer margin of scaphognathite.

First maxilliped (Fig. 4E): Biramous, coxa and basis undifferentiated, flattened; endopod unsegmented, smooth; exopod with 15 marginal setae on proximal part, small setae on distal end; epipod membranous, expanding posteriorly, bearing 5 long setae; 2 small setae present at the distal end of basal endite.

Second maxilliped (Fig. 4F): Biramous, coxa and basis undifferentiated; endopod 4-segmented with 0,1,13,0 setae; exopod incompletely segmented, longer than endopod, 2 small setae at distal end.

Third maxilliped (Fig. 4G): Biramous, coxa and basis differentiated; endopod 5-segmented, carpus with dense setae (~30), propodus with 14 setae, dactylus with 4 long setae on inner margin; exopod segmented, poorly developed with 7 small setae on distal end.

Pereiopods (Fig. 5A): Pereiopods 1–4 biramous, coxa and basis differentiated, endopods 5-segmented with almost equal length, exopods degenerated, merus and carpus bearing a prominent horn at distal end, ischium of pereiopod 2–4 with 4 small spines; Pereiopod 5 uniramous, shortest, merus possessing a prominent horn at the distal end, ischium bearing a conspicuous spine pointing posteriorly.

Pleon (Fig. 3A, 3B): Tergum of pleonite 1 smooth; median carina distinct on tergites of pleonites 2–5; terga of pleonites 2–3 with a few spicules, small spines on median carina, a small tooth at center of posterior margin; terga of pleonites 4–5 smooth, a large tooth present at center of posterior margin; pleura of pleonites 2–5 serrated with large tooth, 2 small spines on the medial margins of pleura.

Pleopods (Fig. 5B): Present on pleonites 2–5; biramous; 2 setae at medial distal angle of protopod; exopod surrounded with 35 (pleopod 1), 37 (2), 38 (3), 33 (4) long plumose natatory setae, each possessing 6 (pleopod 1), 12 (2), 14 (3), 12 (4) small plumose setae at distal end; endopod surrounded with 48 (pleopod 1), 52 (2), 48 (3), 48 (4) long plumose natatory setae, each possessing 0 (pleopod 1), 2 (2), 5 (3), 4 (4) small plumose setae at distal end, appendix interna not reaching distal end of endopod, with approximately 12 cincinnuli at the tip, a plumose seta present just beside the cincinnuli for pleopods 2 and 4.

Uropod (Fig. 5C): A tooth present at lateral margins of exopod and endopod; medial margin of endopod serrated.

Telson (Fig. 5D): A tooth present at the proximal, lateral margins.

Color (Fig. 1): Body entirely transparent in live specimen except a yellow line along the anterior margin of carapace and gills in pink. Specimen preserved in ethanol entirely white with transparent body margins.