Munida lutruwita, McCallum & Ahyong & Andreakis, 2021

McCallum, Anna W., Ahyong, Shane T. & Andreakis, Nikos, 2021, New species of squat lobsters of the genus Munida from Australia, Memoirs of Museum Victoria 80, pp. 113-152 : 131-133

Munida lutruwita sp. nov.

http://zoobank.org/urn:lsid:zoobank.org:act:14904374-57EC-

4548-A4D7-ACA713F712C9

Figures 3E , 12 , 13

Munida cf. manqingae . — Farrelly and Ahyong, 2019:13, 55, fig.99.

Type material. Holotype: NMV J67481 , ovigerous female (cl 11.7 mm, pcl 7.8 mm), Tasmania, south of Hobart, Z 39 Seamount , 44° 23.346' S, 147° 16.376' E, 2040 m, TT 01/2008/J2-387-003, 25 December 2008.

Paratypes (all Tasmania) : NMV J67474 , 2 ovigerous females (cl 9.5 mm, pcl 7.1 mm; cl 9.6 mm, pcl 7.4 mm), Z39 Seamount, 44° 23.32' S, 147° 15.349' E, 1599 m, TT 01/2008/J2-387-023, 26 December 2008 ; NMV J67475 , 2 damaged ovigerous females (cl 10.6 mm, pcl 7.3 mm; cl 11.2 mm, pcl 7.9 mm), Z39 Seamount, 44° 22.994' S, 147° 15.09' E, 1893 m, TT 01/2008/J2-387-008, 25 December 2008 ; NMV J67480 , 1 ovigerous female (cl 11.5 mm, pcl 7.9 mm), Z39 Seamount, 44° 23.295' S, 147° 15.348' E, 1616 m, TT 01/2008/J2-387-022, 26 December 2008 ; NMV J67472 , 1 male (abdomen missing; cl 10.9 mm, pcl 6.3 mm), Z39 Seamount, 44° 23.345'S 147° 16.277'E, 1990–2004 m, TT 01/2008/J2-387-004, 25 December 2008 .

Other material examined. AM P103229 , 1 ovigerous female (cl 14.3 mm, pcl 10.6 mm), Great Australian Bight, 35° 22.627' S, 132° 19.166' E, 1689–1784 m, from crevice in dead coral, IN2015-C01-042, 6 November 2015 .

Description. Carapace. As long as greatest width, widest at midlength. Dorsal surface with main transverse ridges mostly uninterrupted, without secondary transverse striae between main ridges; ridges and striae lined with short, non-iridescent setae. Gastric region with 3 pairs of epigastric spines and 1 or 2 small additional spines, without median row of spines behind rostrum. Hepatic region without spines on dorsal surface. Anterior part of branchial region between cervical groove and postcervical groove with 2 or 3 short tuberculate ridges and often 1 small spine anteriorly; posterior part of branchial region with 5 transverse ridges (excluding posterodorsal ridge). Cardiac region with 2 main transverse ridges. Intestinal region without striae; posterodorsal ridge distinct, without secondary stria. Frontal margin strongly oblique, inclined posteriorly at 115° from midline. Lateral margin slightly convex; anterolateral spine very small, far from reaching sinus between rostrum and supraocular spine; hepatic marginal spine slightly smaller than anterolateral spine; branchial margin with 5 spines. Rostrum spiniform, 0.5 × pcl; supraocular spine 0.25 × length of rostrum, exceeding eyes. Epistomial ridge straight ending at antennal gland; mesial protuberance distinct.

Thoracic sternum. Sternal suface smooth, sternite 4 with only few striae. Sternite 3 0.4 × width of sternite 4. Sterinte 4 anterior margin triangular, narrowly contiguous with sternite 3. Midlength of sternal plastron (sternites 4–7) 0.5 × width of sternite 7.

Abdomen. Somites smooth without spines, distinct ridges or striae. Somite 6 posteromedian margin slightly concave. Telson with few striae; greatest width 1.2 × median length; anterolateral margin weakly concave.

Eye. Maximum corneal diameter 0.18 × distance between anterolateral spines.

Antennule. Basal article (distal spines excluded) overreaching corneae; distolateral spine much longer than distomesial spine; 2 lateral spines, proximal smaller, longer lateral spine not reaching end of distolateral spines.

Antenna. Article 1 distomesial spine almost reaching distal margin of article 2. Article 2 distomesial spine reaching distal margin of article 3; distolateral spine not reaching midlength of article 3. Articles 3 and 4 unarmed.

Maxilliped 3. Ischium 1.9 × merus length, without flexor distal spine. Merus with large median spine and distal spine on flexor margin; extensor margin without distal spine.

P1. Length 2.4–3.2 × pcl, covered in rows of short plumose setae. Merus length 0.9–1.1 × pcl, with row of 2 large spines and 2 small spines on dorsal margin, 1 strong spine on dorsolateral margin, and 4 spines on mesial margin, distomesial spine not reaching midlength of carpus. Carpus 0.5 × merus length, length 3.0 × width, with 6 spines along mesial margin. Propodus 1.3 × merus length, palm with row of 3 or 4 spines on dorsal surface of palm, fingers 0.4–0.5 × total propodus length, without spines on outer margins.

P2–4. Long and slender, with few small scales on lateral sides of meri and carpi; extensor margin with short plumose setae and few longer setae. P2 1.8–2.3 × pcl; merus 0.7–0.8 × pcl, length 8.0 × width, 3.0 × carpus length and 1.5 × propodus length, extensor margin with 5–7 spines, flexor margin with 3 spines and well-developed distal spine; carpus extensor margin with spine at midlength and distal end, flexor margin with distal spine; propodus length about 8 × height, with 5 movable flexor spines on flexor margin; dactylus gently curved distally, 0.6–0.7 × propodus length, length about 7 × height, extensor margin densely lined with stiff short setae on distal half, flexor margin armed along entire length with 12–14 movable spines including spine at base of unguis. End of P2 carpus not reaching end of P1 merus. P3 with similar spination and article proportions as P2; merus 0.9 × P2 merus length, propodus and dactylus as long as those of P2. P4 length 0.7–0.8 × P2 length; merus length 0.3–0.5 × pcl; propodus and dactylus similar in length to those of P3; merocarpal articulation reaching hepatic marginal spine carapace.

Egg diameter. 0.65 mm.

Colour in life. Carapace pink anteriorly fading to white at posterior, abdominal somite 2 white, somites 3–6 pink. P1 and P2–4 white.

Genetic data. COI and 16S; see Table 1.

Etymology. Named lutruwita , the original name of Tasmania in palawa kani, the language of the Tasmanian Aboriginal people, with the approval of the Tasmanian Aboriginal Centre; used as a noun in apposition.

Remarks. Munida lutruwita sp. nov. is very close to M. manqingae Liu, Lin and Huang, 2013 , described from a single female specimen collected from hydrothermal vent fields at 2218 m in the south-western Indian Ocean. The spination of the antenna and antennule is identical between the two species, but the new species differs from M. manqingae in the following:

- the anterior branchial surface of M. lutruwita is rugose, with 2 or 3 rows of small tubercles and a small spine anteriorly, but smooth in M. manqingae .

- the P2 dactylus has 12–14 movable flexor spines in M. lutruwita , but only 10 in M. manqingae .

Munida lutruwita is also very similar to Munida magniantennulata Baba and Türkay, 1992 , described from hydrothermal vents in the Lau Basin near Fiji, and the recently described, M. alba Liu, Li and Lin, 2020 , from the Eastern Pacific Rise. Differences between the three species are as follows:

- the antennal article 1 mesial spine reaches the end of article 2 in M. lutruwita and M. alba , but does not reach as far as the midpoint of article 2 in M. magniantennulata .

- the supraocular spines are parallel or slightly convergent, overreaching the eyes in M. lutruwita , while in M. magniantennulata and M. alba , the suproacular spines are slightly divergent and do not overreach the eyes.

- the frontal margins of the carapace are oblique in M. lutruwita and M. alba rather than near-transverse in M. magniantennulata .

- M. lutruwita and M. magniantennulata further differ from M. alba in the presence of the distal flexor spine on the maxilliped 3 merus (absent in M. alba ) and unarmed outer margin of the cheliped pollex (spinose in M. alba ).

Distribution. Off southern Tasmania and the Great Australian Bight, 1599–2040 m.

Figures

Figure 3. A, Munida abrolhos sp. nov., female paratype, cl 27.5 mm, pcl 18.3 mm (NMV J55262); B–D, Munida julumunyju sp. nov., undetermined paratype from NMV J55979, juvenile paratype, cl 9.2 mm, pcl 10.8 mm (NMV J55061), juvenile paratype cl 10.9 mm, pcl 6.6 mm (NMV J55062); E, Munida lutruwita sp. nov. ovigerous female, cl 14.3 mm, pcl 10.6 mm, (AM P103229). Photos: K. Gowlett-Holmes, CSIRO.

Figure 12. Munida lutruwita sp. nov., holotype, ovigerous female, cl 11.7 mm, pcl 7.8 mm (NMV J67481): A, carapace and abdomen, dorsal view; B, right chela, dorsal view; C, right antenna and antennule, ventral view; D, sternum; E, telson. Scale: A–B = 1 mm, C–E = 2 mm.

Figure 13. Munida lutruwita sp. nov., holotype ovigerous female, cl 11.7 mm, pcl 7.8 mm (NMV J67481): A, right P2 dactylus, lateral view; B, left P2, lateral view; C, left P3, lateral view; D, left P4, lateral view; E, left maxilliped 3, lateral view. Scale = 1 mm.