Paramunida spiniantennata, Mccallum, Anna W., Cabezas, Patricia & Andreakis, Nikos, 2016

Mccallum, Anna W., Cabezas, Patricia & Andreakis, Nikos, 2016, Deep-sea squat lobsters of the genus Paramunida Baba, 1988 (Crustacea: Decapoda: Munididae) from north-western Australia: new records and description of three new species, Zootaxa 4173 (3), pp. 201-224 : 213-216

Paramunida spiniantennata sp. nov.

(Fig. 6,7)

Material examined. Holotype: NMV J67667 , ovigerous female (6.7 mm) north-western Australia, off Broome, SS 05/2007 117, (16°44.412'S 121°1.908'E to 16°45.12'S 121°1.908'E), 109–112m, 30 June 2007.

Paratypes: NMV J56010 , 10 ovigerous females (cl 5.6–6.2 mm), 8 males (5.7–7.5 mm), collected with holotype. NMV J55272 , 1 ovigerous female (6.5 mm), north-western Australia, SS05/2007 172 (13°27.39'S 124°0.66'E to 13°27.654'S 124°0.822'E), 105–107m, 5 July 2007.

Description. Carapace: As long as broad. Covered in long spinules with few short uniramous setae, lacking scale-like striae. Epigastric region with 2 spines, each behind supraocular spine; without median row of spinules behind rostral spine. Mesogastric region with row of 3 well-developed spines in midline. Anterior branch of cervical groove with short setae. Cervical groove deep and broad. Cardiac and anterior branchial regions well circumscribed. Cardiac region with median row of 3 well-developed spines. Posterior margin of carapace preceded by ridge with 1 well-developed spine and numerous spinules. Each branchial region with row of 3 or 4 spines near cardiac region. Frontal margin slightly concave. Lateral margins convex, with a row of spines and iridescent setae on anterior half. Anterolateral spines well developed, slightly exceeding or reaching sinus between rostral and supraocular spines. Rostral spine spiniform, as long as supraocular spines, with thin dorsal longitudinal carina; margin between rostral and supraocular spines slightly concave ( Figs. 6 A, B).

Sternum: Thoracic sternites 4 with few short arcuate striae medially; sternites 5–7 with only few striae on each lateral side ( Fig. 6 C).

Abdomen: Somite 2 much broader than carapace, 1.25 times breadth of carapace. Somites 2–3 with 2 welldeveloped median spines, and row of spines on anterior ridge, posterior ridge with 2 well-developed median spines. Somite 4 with 2 spines on anterior ridge; posterior ridge without distinct single median spine. Ridges with numerous conspicous spinules and small spines ( Fig. 6 A).

A E D F B C a,b,c 5mm d,e,f 2mm A B C

D 2 mm Eyes: Maximum corneal diameter about one-third distance between bases of anterolateral spines.

Antennule: Article 1 slightly exceeding cornea, with distomesial spine as long as distolateral; about twice longer than wide and with fringe of long setae along lateral margin; lateral margin with straight (distal) portion clearly shorter than convex (proximal) portion ( Fig.6 D).

Antenna: Anterior prolongation of article 1 overreaching antennular article 1 by about one-fourth its length and bearing spines on distal dorsal margin. Article 2 about as long as article 3 and as long as wide, mesial and lateral margins armed with small spines, ventral surface with few scales and distomesial spine small and spiniform, not exceeding antennal peduncle and without tuff of setae, far falling short of midlength of anterior prolongation of article 1, not reaching end of article 3; distolateral spine not reaching end of article 3. Article 3 as long as wide and unarmed ( Fig. 6 D, E).

Mxp 3: Ischium about twice length of merus measured along extensor margin, flexor margin bearing long distal spine and row of spines along ventrolateral margin; merus with two well-developed median spines on flexor margin; extensor margin unarmed ( Fig. 6 F).

P 1: Long, slender, squamate, 5.3–6.6 times carapace length; carpus as long as palm length, 10.5–11.5 times longer than high; palm 1.5–1.7 times finger length. Base of carpus without bundle of setae ( Fig. 7 A).

P 2–4: Long and slender, with numerous scales on lateral sides of meri, carpi and propodi; scales with short setae. P2 3.6–4.2 times carapace length, merus 1.7–1.9 times longer than carapace, about 10.9–11.7 times as long as high, 3.9–4.6 times as long as carpus and 1.5–1.6 times as long as propodus; propodus 8.0–8.8 times as long as high, 2.1–2.2 times dactylus length. Merus with well-developed, proximally diminishing spines on extensor border, distalmost larger, flexor margin with few spines and well-developed distal spine; row of small spines along flexolateral margin. Carpus with row of small extensor marginal spines, distal spine larger, flexor margin with distal spine. Propodus with small movable flexor marginal spines. Dactylus compressed, slightly curved, with longitudinal carinae along mesial and lateral sides, ventral border unarmed. End of P2 carpus not reaching end of P1 merus. P3 with similar spination and article proportions as P2; merus slightly shorter than P2 merus; propodus and dactylus slightly longer than those of P2. P4 as long as P2; merus 1.1–1.7 times carapace length; propodus and dactylus as long as those of P3; merocarpal articulation exceeding end of anterior prolongation of article 1 of antennal peduncle ( Figs. 7 B–D).

Etymology. In reference to the spines on the antennal first article.

Remarks. Paramunida spiniantennata sp. nov. is the only species in the genus in which the anterior prolongation of antennal article 1 has spines on the dorsal margin. The new species belongs to a group of species with the rostral spine equal to the supraocular spines and mesogastric region with 3 well-developed spines. P. spiniantennata is closely related to P. microrhina Cabezas, Macpherson and Machordom, 2010 both having a minute distomesial spine on antennal article 2. Paramunida spiniantennata can be distinguished from P. microrhina by the rostrum which is long and spiniform instead of short and triangular. The new species also resembles P. hawaiiensis but can be distinguished by the distomesial spine of the antennal article 2 which never reaches the end of article 3 in the new species but reaches the end of the antennal peduncle in the latter. The genetic divergence betweeen between P. spiniantennata sp. nov. and the sister species, P. microrhina , is 0.07.

Distribution. Presently known only from the type locality, off north-western Australia; 109–112m