Munida macphersoni, Cabezas, Patricia, Lin, Chia-Wei & Chan, Tin-Yam, 2011

Cabezas, Patricia, Lin, Chia-Wei & Chan, Tin-Yam, 2011, Two new species of the deep-sea squat lobster genus Munida Leach, 1820 (Crustacea: Decapoda: Munididae) from Taiwan: morphological and molecular evidence, Zootaxa 3036, pp. 26-38 : 31-33

Munida macphersoni sp. nov.

( Fig. 2 )

Munida distiza . — Baba et al. 2009: 159, figs. 138–139. [Not M. distiza Macpherson, 1994 ]

Material examined. Holotype, Donggang fishing port, Pingtung County, Taiwan, 22 September 2004, 1 ovig. F 11.3 mm ( NTOU A00666 ). Paratype, “ TAIWAN 2000”, stn CP58, 24º26.9´N, 122º81.1´E, 638–824 m, 0 4 August 2000, 1 M 7.1mm ( NTOU A00705).

Etymology. This species name is dedicated to Enrique Macpherson, for his great contribution to the taxonomy of Galatheoidea.

Diagnosis. Dorsal carapace surface with row of 10 epigastric spines. Five spines on branchial margin of carapace. Rostrum spiniform. Second and third abdominal somite with 8 and 4 spines on anterior ridge, respectively. Third to fifth thoracic sternites smooth, lateral part of seventh sternite with coarse granules. Cornea moderately large with maximum corneal diameter about 1/3 distance between anterolateral spines. Distomesial spine of antennular basal segment longer than distolateral spine. Distomesial spine of antennal basal segment reaching end of second segment; distomesial spine of second segment overreaching end of fourth segment; third and fourth segment unarmed. Mxp3 merus unarmed on extensor margin. P1 carpus 3.0–3.5 times longer than broad; fixed finger bearing 2 or 3 lateral spines somewhat remote from the 2 subterminal spines; movable finger with 1 subterminal and 1 basal spine on mesial margin. P2 propodus about 1.3 times dactylus length, flexor margin with 8–10 movable spinules along proximal two-thirds, unarmed on distal third.

Description. Carapace: Approximately 1.2 times longer than wide, slightly convex dorsally. Few secondary striae between main striae. Epigastric region with row of 10 spines. Two pairs of hepatic and parahepatic spines, 1 anterior branchial and 1 postcervical spine on each side. Frontal margins slightly oblique. Lateral margins slightly convex. Anterolateral spine well-developed, situated at anterolateral angle, clearly not reaching level of sinus between rostral and supraocular spines. Second marginal spine anterior to cervical groove smaller than preceding spine. Branchial margins with 5 spines, decreasing in size posteriorly. Rostrum spiniform, horizontal and only slightly upcurved at tip, less than half as long as remaining carapace. Supraocular spines well-developed, reaching midlength of rostrum but falling short of distal end of cornea, subparallel, upwardly directed ( Fig. 2 a).

Abdomen: Second and third somites with 8 and 4 (3 in the holotype) spines on anterior ridge respectively, followed by 2 uninterrupted transverse striae ( Fig. 2 a).

Sternum: Fourth to sixth thoracic sternites smooth, lateral part of seventh sternite with coarse granules. Anterior margin of fourth sternite slightly concave medially; broadly contiguous with posterior margin of third sternite. Transverse ridges on fifth to seventh sternites obtuse ( Fig. 2 b).

Eyes: Moderately large, maximum corneal diameter about 1/3 distance between bases of anterolateral spines ( Fig. 2 a).

Antennule: Basal segment (distal spines excluded) about 0.4 times carapace length, elongate, much more than twice as long as broad, exceeding end of cornea, with 2 distal spines, distomesial one longer than distolateral one; two spines on lateral margin, proximal one short, located distal to midlength of segment, distal one long, reaching end of distolateral spine ( Fig. 2 c).

Antenna: First segment of antennal peduncle with distomesial spine reaching end of second segment (without spines); second segment with 2 distal spines, distomesial spine slightly longer than distolateral spine, overreaching fourth segment, distolateral spine slightly overreaching third segment; third and fourth segment unarmed ( Fig. 2 c).

Maxilliped 3: Ischium nearly 1.3 times length of merus (measured along dorsal margin), and distoventrally bearing well-developed spine. Merus with 2 spines on flexor margin, proximal spine well-developed, distal spine much smaller; extensor margin tuberculated, without distinct spine ( Fig. 2 d).

Pereopod 1 (cheliped): Squamate, more than twice carapace length and covered with few simple setae. Merus about 1.3 times carapace length, twice carpus length, armed with spines, those on mesial border stronger. Carpus 3.0–3.5 times longer than broad, with a few strong spines on mesial margin and several short spines on dorsal side. Palm as long as fingers, with row of spines along mesial border, and a few small spines on dorsal side and distal part of lateral margin. Fingers distally curving and crossing, ending in sharp point; lateral margin of fixed finger with 2 or 3 distinct but irregular spines and 2 regular subterminal spines, mesial margin of movable finger with 1 small subterminal spine and 1 small spine near base ( Fig. 2 e).

Pereopods 2–4 (walking legs): P2 nearly 1.7 times carapace length. Merus shorter than carapace, 7–8 times as long as high, 3–4 times carpus length, and nearly 1.5 times propodus length; dorsal and ventral margins with row of spines. Carpus with 4 dorsal spines and 1 distoventral spine. Propodus 9–10 times as long as high, about 1.3 times dactylus length, ventral margin with 8–10 movable spinules ( Fig. 2 f). Dactylus long and slender, slightly curving distally, flexor margin with 7 or 8 movable spinules, unarmed on distal third ( Fig. 2 g). P3 0.9 times as long as P2, spination and proportions of segments similar to those of P2 ( Fig. 2 h). P4 0.8 times as long as P2; merus nearly half length of P2 merus; merus and carpus relatively less spinose ( Fig. 2 i). Merocarpal articulation of P2 not reaching level of merocarpal articulation of P1; merocarpal articulation of P4 ending at level of anterior branch of cervical groove.

Colour in life. Ground colour of body and appendages orange. Rostral and anterolateral spines reddish orange. Pereopods1–4 with orange and pale orange bands; distal parts of P1 merus and carpus reddish.

Distribution. Known only from Taiwan, between 638–824 m deep.

Remarks. M. macphersoni sp. nov. resembles Munida distiza from New Caledonia, Philippines, Loyalty Islands, French Polynesia, Matthew and Hunter Islands. They can be easily distinguished by the following characters: the spines on the mesial and lateral borders on the P1 fingers are not arranged in rows in the new species, but these spines are in rows in M. distiza . Moreover, the P1 carpus is 3.0–3.5 times longer than broad in the new species, whereas it is about 2 times longer in M. distiza . In addition, the P2 propodus is about 1.3 times as long as the dactylus in M. macphersoni sp. nov., whereas it is about twice longer in M. distiza . Moreover, the third abdominal somite of the new species bears spines. The P2–4 dactyli have spines along the entire flexor margin in M. distiza but these spines are restricted to the basal two third in M. macphersoni sp. nov.

Munida macphersoni sp. nov. resembles M. guttata Macpherson, 1994 from New Caledonia, Loyalty Islands, Futuna, Fiji and Tonga in having the lateral parts of the thoracic sternite 7 with some coarse granules and bearing five spines on the branchial margin of carapace. However, the new species can be distinguished from that species by the presence of a well-developed distal spine on the extensor margin of the Mxp3 merus. The third to fifth thoracic sternites in the new species are smooth, instead of bearing numerous striae as in M. guttata . The distomesial spine of the first antennal segment does not reach the end of distomesial spine of the second segment in M. macphersoni sp. nov., but it does in M. guttata . Furthermore, the P2–4 dactyli have spines along the entire flexor margin in M. guttata but these spines are restricted to the basal two distal third in the new species. They also differ in the body colour; the carapace and abdomen are whitish with small red spots in M. guttata ( Macpherson 1994: fig. 73).

Figures

FIGURE 2. Munida macphersoni sp. nov., holotype ovigerous female 11.3 mm (NTOU A 00666) Taiwan. a, carapace and abdomen, dorsal view. b, sternum. c, left antennule and antenna, ventral view. d, right maxilliped 3, lateral view. e, left P 1, dorsal view, setae omitted. f, right P 2, lateral view. g, dactylus, right P 2, lateral view. h, right P 3, lateral view. i, right P 4, lateral view. Scales: b – d, g = 1 mm; a, e – f, h – i = 5 mm. (a – g from Baba et al. 2009).