Pontopolycope storthynx Kornicker & Iliffe & Harrison-Nelson 2007, new species

Pontopolycope storthynx, new species

Fig. 45

Etymology. The specific name from the Greek storthynx (point, spike) in reference to the spines along the posterior margin of the carapace.

Holotype. USNM 1021454, undissected A- 1 female in alcohol.

Type locality. Exley’s Boiling Blue Hole, South Andros, Great Bahama Bank, Sta 99-054.

Paratype. USNM 1021455, dissected A- 1 female on slide, Sta 99-050.

Distribution. Great Bahama Bank, South Andros: Four Sharks Cave, Exley’s Boiling Hole, depth 60–70 m (Table 12).

Description of A- 1 female (Fig. 45). Carapace oval in lateral view with pointed rostrum, 4 pointed posterior spines, surface ridges and reticulations; surface between reticulations with pebbly texture (after being in glycerine for several months the ridges, reticulations, and pebbly texture are no longer visible and the rostrum is indistinct.) Anteroventral and ventral margin with broad serrated lamellar prolongation (Fig. 45 a,b).

Central adductor muscle attachments (Fig. 45 a,b): Comprising 3 individual oval attachments.

Carapace size (length, height in mm): USNM 1021455, length including rostrum and spines 0.30, length without rostrum and spines 0.26, height 0.23. USNM 1021454, length with rostrum 0.30, length without rostrum 0.26, height 0.23.

First antenna (Fig. 45 c): Segments 1 to 5 fused; 2nd segment with dorsal hairs and long dorsal bristle. Segment 6 with small terminal bristle; segments 7 and 8 fused, with 5 long bristles.

Second antenna: Protopod bare. Endopod obscured on slide; 1st segment elongate bare; 2 distal segments with about 7 long bristles (Fig. 45 d). Exopod segments 1 to 8 with single hirsute bristle; segment 9 with 2 bristles (1 short, 1 long).

Mandible (Fig. 45 e): Coxa endite well developed with flat serrate tip. Basis with 4 hirsute ventral bristles and 1 dorsal bristle near and medial to exopod. Exopod with 2 segments; 1st segment broad; terminal segment diaphanous (indistinct). Endopod with 2 fused segment: segment 1 with ventral bristle and 2 hirsute terminal bristles; 2nd segment with 2 hirsute terminal bristles; dorsal bristle of 2nd segment longer than others and with long stout spines near tip.

Maxilla (Fig. 45 f): Coxa with about 6 bristles. Basis with 2 ventral bristles. Exopod undivided with about 8 terminal bristles. Endopod with 3 segments: segment 1 with 1 ventral bristle; segment 2 with 1 dorsal and 3 ventral bristles; segment 3 with 4 terminal bristles.

Fifth limb: Obscured, approximate morphology and bristles shown in Fig. 45 g.

Furca (Fig. 45 i): Each lamella with 6 articulated claws. Small nonarticulated triangular process between adjacent claws and following claw 6. Pointed unpaired process on body posterior to terminal claw. Posterior of body with rows of spines near furca.

Bellonci Organ (Fig. 45 h): 2 slender bristles (no marginal hairs observed).

Age of specimen. Both specimens in the collection are estimated to be A-1 instars because of having only six claws on each lamella of the furca.

Comparisons. The carapace of the new species P. storthynx differs from those of P. mylax, Pontopolycope rostrata (Müller 1894) and Pontopolycope? moenia ( Joy & Clark 1977) in having three or four posterior spines (appendages unknown for the latter species). The carapace of P. storthynx differs from that of Pontopolycope dentata (Müller 1894) in lacking two dorsal spines. The mandible of P.storthynx differs from that of P. dentata in having a long bristle just proximal to the exopod and in lacking a bristle on the exopod.