Paramunida ioannis, 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 : 210-212

Paramunida ioannis sp. nov.

( Fig. 4)

Material examined. Holotype: NMV J57244 , 1 ovigerous female (cl 9.9 mm), north-western Australia, SS05/2007 63 (17°35.982'S, 119° 59.07'E – 17°38.574'S, 119°1.26'E), 222–319 m, benthic sled, 16 July 2007.

Description. Carapace: As long as broad. Spinules on gastric and hepatic regions arising from scale-like striae and with few short uniramous setae. Epigastric region with 2 spines, each behind supraocular spine; with median row of spinules behind rostral spine and scattered spinules on surface between rostal spine and supraocular spines. Mesogastric region with 3 well-developed spines in midline, first larger than others. Anterior branch of cervical groove with short setae. Cervical groove distinct. Cardiac and anterior branchial regions slightly circumscribed. Cardiac region with median row of three well-developed spines, first and second stronger than third. Posterior margin of carapace preceded by ridge with numerous spinules. Each branchial region with row of 3 spines near cardiac region. Frontal margin slightly concave. Lateral margins convex, with row of spines and iridescent setae on anterior half. Anterolateral spine well-developed, slightly exceeding sinus between rostral and supraocular spines. Rostral spine spiniform, larger than supraocular spines, with thin dorsal longitudinal carina; margin between rostral and supraocular spines slightly concave ( Figs. 4 A, B).

Sternum: Thoracic sternites 4 with few short arcuate striae medially; sternites 5–6 with numerous lateral striae on lateral sides, sternite 7 smooth ( Fig. 4 C).

Abdomen: Somite 2 slightly broader than carapace, 1.1 times breadth of carapace. Somites 2–3 each with two well-developed spines on anterior ridge, 2 median spines on posterior ridge. Somite 4 with 2 spines on anterior ridge; distinct median spine on posterior ridge. Anterior ridges with numerous spinules ( Fig. 4 A).

Eyes: Maximum corneal diameter more than one-third distance between bases of anterolateral spines.

Antennule: Article 1 slightly exceeding corneae, with small distomesial spine and distolateral angle without distinct spine; 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. 4 D).

Antenna: Anterior prolongation of article 1 overreaching antennular article 1 by about one-third its length. Article 2 about twice as long as article 3 and 1.6 times longer than wide, ventral surface with scales; distomesial spine spiniform, not exceeding antennal peduncle and without tuft of setae, almost reaching midlength of anterior prolongation of article 1, exceeding end of article 3; distolateral spine not reaching end of article 3. Article 3 nearly 1.5 times longer than wide and unarmed ( Fig. 4 D).

Mxp 3: Ischium about twice length of merus measured along extensor margin, flexor margin bearing long distal spine; merus with well-developed median spine on flexor margin; extensor margin unarmed ( Fig. 4 E).

P1: Long and slender, squamate, 4.7 times carapace length; carpus as long as palm, 5.5 times longer than high; palm 1.1 times finger length. Base of carpus without bundle of setae ( Fig. 4 F).

P2–4: Long and slender, with numerous scales on lateral sides of meri, carpi and propodi; scales with short setae. P2 3.1 times carapace length, merus about as long as carapace, about 8 times as long as high, 3.7 times as long as carpus and 1.6 times as long as propodus; propodus 8 times as long as high, 1.4 times dactylus length. Merus with well developed spines on extensor border, increasing in size distally, flexor margin with few spines and well-developed distal spine; row of small spines along flexolateral margin. Carpus with row of well-developed extensor marginal spines; distal spine on extensor and flexor margin. Propodus with small movable flexor spines. Dactylus compressed, slightly curved, with longitudinal carinae along mesial and lateral sides, flexor border unarmed. End of P2 carpus not reaching end of P1 merus. P3 with similar spination and article proportions as P2; merus slightly longer than P2 merus; propodus and dactylus slightly longer than those of P2. P4 slightly longer than P2; merus 1.4 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. 4 G–I).

A

D

F E

G H

I B C a,b,c 5mm

d,e 2mm

f,g,h, i 5 mm Etymology. For Ioannis , son of N. Andreakis.

Remarks. We tentatively describe this new species based on a single specimen. It is close to Paramunida cretata , but can be distinguished by the following subtle morphological differences:

- the length of the antennal article 2 is 1.6 times longer than wide, and twice as long as article 3 in P. ioannis sp. nov., whereas in P. cretata , the antennal article 2 is only slightly longer than wide, and 1.4 times longer than article 3.

- the ventral surface of antennal article 2 is covered in numerous scales whereas in P. cretata , it is smooth. - the sternum has numerous lateral striae on sternites in 5–6 in P. ioannis sp. nov., whereas P. cretata has only a few lateral striae.

The genetic divergence betweeen between P. ioannis sp. nov. and P. cretata is 0.03 substitutions/site. These two species are also geographically isolated as P. cretata is known from Waterwitch Bank, the Wallis Islands, and Fiji ( Macpherson 1996; Cabezas et al. 2010).

Distribution. North-western Australia, 222– 319 m.