Eumunida notialis, Tavares & Lima, 2019

Tavares, Marcos & Lima, Daniel, 2019, First record of the genus Eumunida Smith, 1883 (Crustacea, Decapoda, Eumunididae) from the southwestern Atlantic, with the description of a new species, Papéis Avulsos de Zoologia (Pap. Avulsos Zool., S. Paulo) 59, pp. 1-10 : 2-8

publication ID	https://doi.org/ 10.11606/1807-0205/2019.59.39
publication LSID	lsid:zoobank.org:pub:87F53162-D3A9-430D-BBCA-2430C9E85FCA
persistent identifier	https://treatment.plazi.org/id/3D0F87E2-3D1D-FF88-F5BB-F92990A5364B
treatment provided by	Carolina
scientific name	Eumunida notialis
status	sp. nov.

Treatment

Eumunida notialis sp. nov.

Figs. 2 View Figure 2 , 3A, C, G View Figure 3 , 4 View Figure 4 A-C, 5A, 6A, 7A, E, F

Type material: Holotype,male,cl 59 mm ( MZUSP 25986 View Materials ), F/ V “ Cordeiro de Deus I”, Brazil, off Rio Grande do Sul, 31°45’54.0”S, 49°54’32.4”W, tangle net, sampling 3, 03.v. 2011, 392 m. GoogleMaps

Comparative material: Eumunida picta Smith, 1883: 1 juvenile male, cl 10.5 mm, paralectotype ( USNM 19293 View Materials ), Massachussetts, off Martha’s Vineyeard, R / V “Albatross”, stn 1098, 39°52’48.0”N, 69°43’12.0”W, 11.viii.1882, trawl, 285 m. 1 juvenile male, cl 10.8 mm, 1 juve- nile female cl 5.4 mm, paralectotypes ( USNM 19291 View Materials ), Massachussetts, off Martha’s Vineyeard, R / V “Albatross”, stn 1038, 39°58’00.0”N, 70°06’00.0”W, 21.ix.1881, trawl, 267 m. 1 juvenile male, cl 10.2 mm, paralectotype ( USNM 19294 View Materials ), Massachussetts, off Martha’s Vineyeard, R / V “Albatross”, stn 1152, 39°58’12.0”N, 70°58’48.0”W, 04.x.1882, trawl, 210 m. 1 juvenile female, cl 42 mm ( USNM 1136763 View Materials ), off New Jersey, Slope II, CASPS Expedition, DSR/ V “Johnson Sea Link”, Cruise JSL-1081, stn 5, 01.viii. 1981, 200 m. Lectotype, male, cl 16 mm ( USNM 7304 View Materials ), off Delaware Bay, R / V “Albatross”, stn 1043, 38°39’00.0”N, 73°10’48.0”W, 10.x.1881, trawl, sand, 238 m. 1 male, cl 17 mm ( USNM 8891 View Materials ), Virginia, off Chesapeake Bay, R / V “Albatross”, stn 2264, 37°07’50.2”N, 74°34’19.9”W, 18.x.1884, trawl, gray sand, 305 m. 1 ovigerous female, cl 35 mm ( USNM 268766 View Materials ), South Carolina, off Charleston GoogleMaps , R / V “ Oregon II ”, Cruise GoogleMaps 33, stn 11744, 32°34’12.0”N, 77°37’12.0”W, 29.i.1972, depth unknown. 1 male, cl 44 mm ( USNM 135265 View Materials ), east of Mississippi Delta GoogleMaps , Louisiana, Gulf GoogleMaps of Mexico, R / V “ Oregon II ”, Cruise GoogleMaps 79, stn 3691, 29°06’29.9”N, 88°18’00.0”W, 10.viii. 1962, 430 m.

Eumunida bella de Saint Laurent & Macpherson, 1990: 1 male, cl 25 mm, paratype (USNM 22913), western Sahara,Cape Bojador,R/V“Talisman”,stn 73, 25°39’00.0”N, 18°58’12.0”W, 09.vii. 1883, 698 m.

Distribution: So far known only from the type locality.

Etymology: The species name is derived from the Latin notialis (southern); a reference to its discovery in the southwestern Atlantic.

Diagnosis: Carapace with three anterolateral spines;ultimate transverse ridge entire across carapace; four hepatic spines; two inframarginal spines below anterolateral spines. Anterolateral spine of second pleonal tergite obsolete. Fourth antennal segment with strong,acute spine on anteroventrolateral angle. Antennal acicle spiniform, slender, extending to almost the articulation between fourth and fifth antennal segments. Cheliped propodus without dorsolateral and dorsomesial, longitudinal rows of spines; carpus without longitudinal row of strong spines on dorsomesial surface, armed with three distal spines (dorsal, dorsomesial, ventromesial).Third thoracic sternite with shallow, U-shaped anterior margin.

Description: Carapace slightly wider than long (excluding rostral spine). Gastric region well defined, strongly convex. Four hepatic spines; first spine strong, near base of lateral supraocular spine; second and third hepatic spines much smaller than first, subequal in size; fourth spine smallest, located below the third spine ( Figs. 1 View Figure 1 , 5A View Figure 5 , 6A View Figure 6 ). Cervical groove ( Fig.2 View Figure 2 ) bifurcating downward to form postcervical groove. Grooves separating cardiac and branchial areas well developed. Transverse ridges as illustrated ( Figs. 2 View Figure 2 , 3C View Figure 3 ), bordered with dense short setae anteriorly. Anterior branchial region smooth, with few minute squamiform granules. Six transverse ridges behind cervical groove, first to fifth entire medially, interrupted laterally; ultimate transverse ridge entire across carapace ( Figs. 1 View Figure 1 , 2 View Figure 2 ). Three anterolateral spines anterior to postcervical groove, posteriormost spine minute ( Figs. 1 View Figure 1 , 2 View Figure 2 ). Branchial margins distinctly convex, armed with four spines decreasing in size posteriorly. Carapace greatest width at the level of fourth branchi- al marginal spine. Two supraorbital spines; mesial supraorbital spine longest, much more than half length of rostral spine, acute; lateral supraorbital spine much less than half length of mesial supraorbital spine, acute ( Figs. 1 View Figure 1 , 2 View Figure 2 , 5A View Figure 5 , 6A View Figure 6 ). Two inframarginal spines below anterolateral spines ( Figs. 1 View Figure 1 , 5A View Figure 5 , 6A View Figure 6 ). Pterygostomial spine, strong, acute ( Figs. 1 View Figure 1 , 5A View Figure 5 , 6A View Figure 6 ); pterygostomial flap with few oblique striae. Branchiostegal area with sparse minute squamae, bordered with dense short setae anteriorly.

Sternal plastron medially concave; anterior margin of third thoracic sternite U-shaped, shallowly incised, with pair of obsolete,setiferous median processes ( Figs.1 View Figure 1 , 3A View Figure 3 ); fourth thoracic sternite with prominent lateral spine and setiferous transverse ridges ( Figs. 1 View Figure 1 , 3A View Figure 3 ).

Second pleonal tergite as illustrated ( Fig. 3C, G View Figure 3 ); two transverse ridges dorsally, few short striae laterally; anterolateral spine obsolete ( Fig. 3G View Figure 3 ).

Rostral spine sharply spiniform (broken distally), slightly curved upwards, much longer than lateral supraorbital spines ( Figs. 1 View Figure 1 , 2 View Figure 2 ).

Eye extending far beyond end of lateral supraorbital spine; cornea strongly dilated, dark black ( Fig. 5A View Figure 5 ).

First segment of antennal peduncle with short, acute, broad triangular,distolateral spine;second segment with well developed, sharp distolateral spine much shorter than mid-length of acicle; third segment with long distal spine, overreaching end of fourth segment (exclusive of subdistal, ventral spine); fourth segment with strong ventromesial spine slightly exceeding fifth antennal segment (exclusive of distal spines); fifth segment with three spines distally (mesial, lateral, ventromesial). Acicle spiniform, slender, extending almost to anterior margin of fourth segment ( Fig. 7A View Figure 7 ).

Merus of third maxilliped with small,acute spine on distal third of mesial margin ( Fig.7E,F View Figure 7 ). Ischium crista dentata with 15-17 denticles (left and right ischium, respectively).

Chelipeds subequal, subcylindrical, 4.2 cl. Ischium squamate with strong, acute, ventromesial, subdistal spine, and several small, acute, ventral spines. Merus squamate, slightly less than twice carapace length, armed with four longitudinal rows of spines (mesial, dorsal, dorsolateral, ventromesial); mesial row alternating large and small strong spines; dorsal row with large and small, strong, acute spines; dorsolateral row with small, acute spines; ventromesial with small, acute spines. Carpus squamate, armed with three strong distal spines (dorsal, dorsomesial, ventromesial); two longitudinal rows of spines (dorsolateral and lateral rows with acute, blunt small spines, respectively; dorsomesial row absent). Palm and fixed finger squamate, densely covered with short, velvet-like setae; palm 1.4 times length of fixed finger, massive, without rows of spines ( Fig. 4 View Figure 4 A-C). Chela with two pads, one large on ventral surface of palm near base of fixed finger, one small pad near base of dactylus ( Fig. 4A View Figure 4 ).Dactylus squamate,densely covered with velvet, short setae. Fingers slightly gapping proximally, cutting margins as illustrated ( Fig. 4A, B View Figure 4 ).

First three walking legs similar, squamate, sparsely furnished with long setae. Merus with strong, acute, distal spine on lateral surface. Extensor margins of merus and carpus with row of strong, acute spines, increasing in size anteriorly. Propodus slightly more than twice as long as dactylus,armed with row of 14-18 spinelets along flex- or margin. Dactylus ending in corneous tip, with 10-12 movable, corneous spinules, along flexor margin. First walking leg with longitudinal row of strong, acute spines along flexor margin. Third walking leg with a longitudinal row of spinelets along lateral surface.

Remarks: Eumunida notialis sp. nov. ( Fig. 2 View Figure 2 ) is superficially similar to its Atlantic congeners in the possession of a pair of strong spines on the anterolateral margin of the fourth thoracic sternite ( Figs. 1C View Figure 1 , 3A, B View Figure 3 ), a distinct pad on the cheliped palm ( Fig. 4A View Figure 4 ), eyes extending far beyond the end of the lateral supraorbital spines ( Fig. 5A View Figure 5 ), and in having the lateral surface of the fourth pereopod merus with a longitudinal row of spines.

However, the new species differs from all its Atlantic counterparts in having (1) four hepatic spines, Figs. 1A, B View Figure 1 , 5A View Figure 5 , 6A View Figure 6 (versus three spines in the remaining Atlantic species, Figs. 5 View Figure 5 B-D, 6B-D; (2) two carapace inframarginal spines, Figs. 1A View Figure 1 , 5A View Figure 5 , 6A View Figure 6 (versus one in E. bella and E. squamifera and no inframarginal spine in E. picta , Figs. 5B, C View Figure 5 , 6 View Figure 6 B-D); (3) the distal end of the antennal acicle nearly reaching to the articulation between fourth and fifth antennal segments, Fig. 7A View Figure 7 (versus antennal acicle distinctly overreaching the articulation between the fourth and fifth antennal segments, Fig. 7 View Figure 7 B-D); and (4) the anterolateral spine of the second pleonal tergite obsolete, Fig. 3C, G View Figure 3 (versus anterolateral spine of the second pleonal tergite strong in the remaining Atlantic species, Fig. 3 View Figure 3 D-F, H).

The closest morphological resemblance of E. notialis sp. nov. is with E.picta of which it can be further separat- ed by having one strong, acute spine on the anteroventrolateral angle of the fourth antennal segment, Fig. 7A View Figure 7 (versus anteroventrolateral spine of the fourth antennal segment obsolete in E. picta , Fig. 7B View Figure 7 ).

The new species further differs from both E. bella and E.squamifera in the absence of a dorsolateral and dorsomesial, longitudinal rows of spines on the cheliped propodus, Fig. 4 View Figure 4 A-C (versus dorsolateral and dorsomesial, longitudinal rows of spines on the cheliped propodus present in both E.bella and E.squamifera ( Fig. 4D, E View Figure 4 , respectively).

Eumunida notialis sp. nov. additionally differs from E. bella in having (1) minute second and third hepatic spines, Figs. 1A View Figure 1 , 5A View Figure 5 (versus strong second and third hepatic spines in E.bella , Fig.5C View Figure 5 ) and (2) the anterior margin of the third thoracic sternum U-shaped,shallowly incised, Figs. 1C View Figure 1 , 3A View Figure 3 (versus anterior margin of the third thoracic sternum deeply incised in E. bella , Fig. 3B View Figure 3 ), and further differs from E.squamifera in having the carapace ultimate transverse ridge entire across carapace, Figs. 1B View Figure 1 , 3C View Figure 3 (versus carapace ultimate transverse ridge fragmented into short striae of variable length in E. squamifera , Fig. 3F View Figure 3 ).

According to de Saint Laurent & Macpherson (1990) E. bella , E. picta and E. squamifera have three anterolateral spines on the carapace, although the presence or absence of the posteriormost spine varies over ontogeny in E. picta (posteriormost spine small in adults, lacking in young specimens). Conversely, Puillandre et al. (2011) attributed one anterolateral spine to both E. bella and E.squamifera , and two anterolateral spines to E.picta . The holotype of E. bella (adult, cl 46 mm) and the lectotype of E. picta (young, cl 16 mm) have three and two anterolateral spines, respectively ( Fig. 5E, F View Figure 5 ).The holotype of E.notialis sp. nov. (adult, cl 59 mm) has three anterolateral spines, with the posteriormost one being minute ( Fig. 2 View Figure 2 ).

Baba & Wicksten (2019) recently described E. subsolanus Baba & Wicksten, 2019 , which represented the first record of the genus from the eastern Pacific (Galapagos Islands). Eumunida subsolanus superficially resembles E. treguieri de Saint Laurent & Poupin, 1996 from French Polynesia, and E. depressa de Saint Laurent & Poupin, 1996 , from Japan (viz. Baba & Wicksten, 2019). Eumunida notialis sp. nov. can be distinguished outright from E.subsolanus in having four hepatic spines, four branchial marginal spines, and two inframarginal spines below the anterolateral spines (versus three hepatic spines, six branchial marginal spines, and no inframarginal spines below the anterolateral spines in E. subsolanus ; viz. Baba & Wicksten, 2019). Additionally, E. notialis sp. nov. (cl 59 mm) is much larger than E. subsolanus (cl 6 mm). The new species can be immediately separated from E. treguieri and E. depressa in having four longitudinal rows of spines on the merus of the chelipeds and the branchial region of the carapace evenly convex, respectively (versus three longitudinal rows of spines in E. treguieri and a depressed area on each lateral branchial surface of the carapace in E.depressa ).