Gammarus pontual, Andrade & Tavares & Senna, 2021

Andrade, Luiz Felipe, Tavares, Marcos & Senna, André Resende de, 2021, A new species of Gammarus Fabricius, 1775 (Crustacea: Amphipoda: Gammaridae) from extreme high-altitude Lake Tong Tso, Qinghai-Tibetan Plateau, Papéis Avulsos de Zoologia (Pap. Avulsos Zool., S. Paulo) 61, pp. 1-13 : 2-12

publication ID	https://doi.org/ 10.11606/1807-0205/2021.61.46
publication LSID	lsid:zoobank.org:pub:2CD59E7F-D68B-4779-B3C5-CB4D1B49A3CA
persistent identifier	https://treatment.plazi.org/id/03961F1B-FF8B-FFDB-E0C9-8259133DFA98
treatment provided by	Carolina
scientific name	Gammarus pontual
status	sp. nov.

Treatment

Gammarus pontual sp. nov.

( Figs. 1-8 View Figure 1 View Figure 2 View Figure 3 View Figure 4 View Figure 5 View Figure 6 View Figure 7 View Figure 8 )

Material examined: Holotype, male, 41.1 mm, in ethanol 70%, habitus illustrated, Lake Tong Tso , approximately 32°10′0″N, 84°42′0″E, Qinghai-Tibetan Plateau, 10-20 cm depth,coll. F. Pontual, August-September,2000 ( MZUSP 40976 View Materials ). GoogleMaps

Paratypes: 1 male, 27.0 mm, dissected and illustrated, same sampling data as holotype( MZUSP 40977 View Materials ) GoogleMaps ; 3 males, 16.6 mm, 17.8 mm, and 21.4 mm, in ethanol 70%, same sampling data as holotype ( MZUSP 40130 View Materials ) GoogleMaps .

Diagnosis: Head with deep antennal sinus. Maxilla 2 inner plate with a very dense facial oblique row of setae. Gnathopod 1 propodus weakly armed, lateral margin with 1 stout seta defining palm, palm longer than posterior margin of propodus, with a truncated projection bearing 1 stout seta medially. Gnathopod 2 propodus weakly armed, palm lateral margin with a proximal large subrounded projection bearing 1 main stout seta. Pereopods 5-7 basis slender, posterior margin crenulate. Epimeral plate 1 posterior margin produced into a short spine, facial ridge present. Epimeral plates 2-3 posteroventral corner sharply pointed. Uropod 3 rami covered with plumose setae. Telson apex with 2 stout setae on each side.

Description: Based on male holotype (MZUSP 40976) and male paratype (MZUSP 40977). Habitus as in Fig. 1A View Figure 1 . Head ( Fig. 2A View Figure 2 ), cephalic lateral lobe truncated, antennal sinus deep, eyes small and ovate. Antenna 1 ( Fig. 2B View Figure 2 ) about 1.2 times longer than antenna 2, peduncular articles 1-3 with length ratio of 1.0: 0.8: 0.4, weakly setose; accessory flagellum 3-articulate; main flagellum 23-articulate, calceoli absent. Antenna 2 ( Fig. 2C View Figure 2 ) peduncular articles 3-5 with length ratio of 1.0: 2.4:2.5; article 2 short, gland cone straight, almost reaching apex of third article; article 3 with main lateral ridge bearing 7 setae and small hump with 3 setae; article 4 ventral margin with 6 short brush setae proximally and 8 clusters of short to long setae laterally; article 5 ventral margin with 1 long seta distally, 9 clusters of short to long setae laterally; flagellum 14-articulate, calceoli absent. Upper lip ( Fig. 2D View Figure 2 ) ventral margin rounded, setulose. Lower lip ( Fig. 2E View Figure 2 ) outer lobes large, setulose, inner lobes indistinct. Left mandible ( Fig. 2F View Figure 2 ) incisor with 5 spines; lacinia mobilis with 4 spines; accessory setal row with 10 plumose setae; molar triturative, with 1 plumose seta; palp articles 1-3 with length ratio of 1.0: 2.5: 2.0; article 2 with 18 setae; article 3 facial margin with 3 clusters of setae,mesial margin with 32 weakly serrulated setae and 7 slender setae apically. Right mandible ( Fig. 2G View Figure 2 ) incisor with 4 spines; lacinia mobilis apically trifid, facially multicuspidate; accessory setal row with 8 plumose setae; molar triturative, with 1 long plumose seta; palp articles 1-3 length ratio of 1.0: 2.4: 1.9; article 2 with 16 setae; article 3 facial margin with 3 clusters of setae, mesial margin with 28 pectinate setae and9slender setae apically. Maxilla1 ( Fig.3A View Figure 3 )inner plate with 30 plumose setae, facial and apicolateral margins covered with setules; outer plate mesial margin with row of setules, apically with 9 serrate stout setae, facially with oblique row of setules, ending in setulose field; left palp 2-articulate, bearing 9 setae apically, 6 subapically; right palp ( Fig. 3B View Figure 3 ) apical margin with 6 short stout and 2 slender setae. Maxilla 2 ( Fig. 3C View Figure 3 ) inner plate about 0.9 times length of outer plate, strongly setose, with facial oblique row of 53 slender setae, laterally and facially covered with setules; outer plate setose apically, lateral and facial margins covered with setules. Maxilliped ( Fig. 3D View Figure 3 ) inner plate with 3 apical and 1 subapical stout setae, mesial and apical margins covered with plumose setae, facial margin with oblique row of 7 multicuspidate setae; outer plate mesial margin with 15 stout setae, apical margin with 3 serrate and 5 plumose setae, lateral margin covered with setules; palp 4-articulate, article 1 mesial margin with 5 setae, article 2 mesial margin setose, apicolateral corner with row of 6 setae, article 3 with oblique facial row of 8 pectinate setae, lateral margin with 3 clusters of setae, apicolateral corner produced into a hump, article 4 about half the length of article 3, with 6 short setae distally, bearing one medium nail.

Gnathopod 1 (lateral view) ( Fig. 4A View Figure 4 ) coxa subrectangular, anteroventral and posteroventral corners with small spine bearing 1 short seta each; basis about 2.5 times longer than wide, margins with short to long setae, posterior margin with 4 serrate setae and 1 pectinate setae distally; ischium posterior margin with 8 setae distally; merus posterior margin weakly setose; carpus about 0.7 times length of propodus, anterior margin with 4 cluster of setae, posterior margin setose with pectinate setae; propodus about 1.3 times longer than wide, anterior margin with 8 setae distally, posterior margin with 3 clusters of setae, 1 stout seta defining palm; palm 1.4 times longer than posterior margin of propodus, proximally with truncate projection bearing 1 stout seta and two pairs of stout setae medially and distally; dactylus shorter than palm, outer margin with 1 seta, nail present. Gnathopod 1 (mesial view) ( Fig. 4B View Figure 4 ) ischium posterior margin with row of 11 setae extending to facial margin; merus facial margin with subdistal ridge bearing 17 setae; merus anterior margin with 3 clusters of setae, posterior margin setose with pectinate setae, facial margin with 2 rows of 6 and 15 setae medially and distally, respectively; propodus anterior margin with tuft of setae distally, posterior margin weakly setose, 1 stout seta defining palm, facial margin with clusters of slender se- tae and 2 clusters bearing 3 stout and 1 slender setae, plus 1 stout and two slender setae; palm covered with short setae, distally crenulate towards palmar corner. Gnathopod 2 (lateral view) ( Fig. 5A View Figure 5 ) coxa subrectangular, tapering distally, anteroventral and posteroventral corners with small spine bearing 1 short seta each; basis about 2.7 times longer than wide, margins with short to long setae, posterior margin with 5 distal serrate setae decreasing in length; ischium posterior margin with 5 setae distally; merus facial margin with row of 20 setae distally; carpus about 0.7 times length of propodus, anterior margin with 3 clusters of setae, posterior margin setose with pectinate setae; propodus about 1.5 times longer than wide, anterior margin with 11 setae distally, posterior margin moderately setose, with 1 stout seta defining palm;palm 0.6 times length of posterior margin of propodus, with large subrounded projection bearing 1 main stout seta medially, distally with another subrounded projection and two stout setae decreasing in length; dactylus slightly longer than palm, outer margin with 1 seta, nail present. Gnathopod 2 (mesial view) ( Fig. 5B View Figure 5 ) ischium posterior margin with row of 11 setae extend- ing to facial margin; merus facial margin with 2 rows of long setae; carpus anterior and facial margins with cluster of setae, posterior margin setose with pectinate setae; propodus posterior margin covered with pectinate setae, facial margins with many clusters of slender setae, one with 3 stout setae; palm minutely crenulate, covered with short setae. Pereopod 3 ( Fig. 6A View Figure 6 ) coxa anteroventral corner with 1 short seta,posteroventral corner with small spine bearing 1 short seta; basis about 3.7 times longer than wide, margins moderately setose; ischium posterior margin with 5setae distally;merus,carpus,propodus and dactylus with length ratio of 1.0: 0.6: 0.6: 0.2; merus anterior margin with 4 clusters of setae with 1 stout seta each, posterior margin setose, facial margin with 5 clusters of setae; carpus anterior margin with 1 stout and 5 slender setae distally,posterior margin setose, with 4 stout setae; propodus anterior margin with 3 setae distally, posterior margin moderately setose, with 7 stout setae; dactylus anterior margin with 1 short plumose seta proximally, facial and posterior margins with 1 seta each, nail present. Pereopod 4 ( Fig. 6B View Figure 6 ) coxa narrow, about 1.2 times longer than wide, excavate posterodorsally, anteroventral corner with 2 short setae; basis about 3.6 times longer than wide, margins moderately setose; ischium posteri- or margin with 7 setae distally; merus, carpus, propodus and dactylus with length ratio of 1.0: 0.7: 0.7: 0.2; merus anterior margin with 1 stout and 4 slender setae distal- ly, posterior margin setose; carpus anterior margin with 1 stout and 3 slender setae, posterior margin setose,with 5 stout setae; propodus anterior margin with 4 setae distally,posterior margin moderately setose,with 9 stout setae; dactylus anterior margin with 1 short plumose seta proximally, facial and posterior margins with 1 seta each, nail present. Pereopod 5 ( Fig. 6C View Figure 6 ) coxa bilobate, ante- rior lobe with 1 seta, posterior lobe with 2 setae; basis about 1.6 times longer than wide, tapering distally, anterior margin with 10 stout setae, posterior margin weakly crenulate, with 10 setae; ischium anterior margin with 1 slender and 2 stout setae; merus, carpus, propodus and dactylus with length ratio of 1.0: 1.2: 1.0: 0.3; merus anterior and posterior margins with 4 and 3 clusters of stout setae, respectively; carpus anterior and posterior margins with 5 clusters of stout setae each; propodus with 6 clusters of stout setae; dactylus facial and anterior margins with 1 seta each, nail present. Pereopod 6 ( Fig. 6D View Figure 6 ) coxa bilobate, anterior margin with 3 setae, posterior margin with 2 setae; basis about 1.8 times longer than wide, tapering distally, anterior margin with 7 stout setae, posterior margin crenulate, with 10 short setae; ischium anterior margin with 4 stout setae distally; merus, carpus, propodus and dactylus with length ratio of 1.0: 1.3: 0.9: 0.2; merus anterior and posterior margins with 4 and 3 clusters of stout setae, respectively; carpus anterior and posterior margins with 6 and 7 clusters of stout setae, respectively; propodus with 5 clusters of stout setae; dactylus anterior margin with 1 seta each, nail present. Pereopod 7 ( Fig. 6E View Figure 6 ) coxa anterior margin with tuft of 3 setae, posterior margin weakly crenulate, with 4 setae; basis about 1.9 times longer than wide, tapering distally, anterior margin with 8 stout setae, posterior margin crenulate, with 13 setae; ischium anterior margin with 4 stout setae; merus, carpus, propodus and dactylus with length ratio of 1.0: 1.6: 1.2: 0.3; merus anterior and posterior margins with 3 clusters of stout se- tae each; carpus anterior and posterior margins with 5 and 4 clusters of stout setae, respectively; propodus with 6 clusters of stout setae and 2 of slender setae; dactylus anterior margin with 1 short seta, nail present.

Epimeral plate 1 ( Fig. 7A View Figure 7 ) anterior margin with 11 setae extending to anteroventral corner, facial ridge present, posteroventral corner with short spine bearing 1 short seta, posterior margin rounded. Epimeral plate 2 ( Fig. 7B View Figure 7 ) anterior margin weakly concave, facial ridge present, with 1 facial stout seta, ventral margin with 3 submarginal stout setae, posteroventral corner sharply pointed, posterior margin with 3 setae. Epimeral plate 3 ( Fig. 7C View Figure 7 ) anterior margin weakly concave, anteroventral corner with 2 stout setae, ventral margin with 1 submarginal stout seta, posteroventral corner sharply pointed, posterior margin with 1 seta. Pleopod 1 ( Fig. 8A View Figure 8 ) peduncle with sparse clusters of setae, innerdistal margin with 2 retinacula and 3 slender setae;rami subequal,covered with plumose setae, with 21-24 articles. Pleopod 2 ( Fig. 8B View Figure 8 ) peduncle with sparse submarginal clusters of setae, innerdistal margin with 2 retinacula and 2 slender setae; rami subequal, covered with plumose setae, with 21-23 articles. Pleopod 3 ( Fig. 8C View Figure 8 ) peduncle with sparse clusters of setae, innerdistal margin with 2 retinacula and 2 slender setae; rami subequal, covered with plumose setae, with 21-25 articles. Urosomite 1 ( Fig. 1B View Figure 1 ) dorsally with 2-2-2 stout setae. Urosomite 2 ( Fig. 1C View Figure 1 ) dorsally with 1-2-1 stout setae accompanied by slender setae. Urosomite 3 ( Fig. 1D View Figure 1 ) dorsal margin with 2-0-2 stout setae, bearing 2 slender setae in the middle. Uropod 1 ( Fig. 7D View Figure 7 ) peduncle about 4.4 times longer than wide, with 1 stout basofacial seta, dorsomesial margin with 2 stout setae, dorsolateral margin with 4 stout setae; inner ramus slightly longer than outer, about 0.7 times the length of peduncle, dorsal margin naked, apically with 5 stout setae; outer ramus about 0.6 times the length of peduncle, dorsal margin with 1 stout seta, apically with 4 stout setae. Uropod 2 ( Fig. 7E View Figure 7 ) peduncle about 3.3 times longer than wide, dorsomesial margin with 2 stout setae, dorsolateral margin with 3 stout setae; inner ramus about 1.4 times longer than outer and slightly shorter than peduncle, dorsal margin with 1 stout seta, apically with 5 stout setae; outer ramus dorsal margin with 2 stout setae, apically with 5 stout setae. Uropod 3 ( Fig. 7F View Figure 7 ) peduncle about 1.5 times longer than wide, distolaterally with 1 slender and 5 stout setae, distomesially with 1 stout seta; outer ramus about 1.2 times longer than inner, covered with long plumose setae, ventral margin with 2 pairs of 2 stout setae, article 2 short, apically with 4 long plumose setae; inner ramus covered with plumose setae. Telson ( Fig. 7G View Figure 7 ) slightly longer than wide, about 80% cleft, exceeding the peduncle of uropod 3, apically with 2 stout, 1 brush and 5 slender setae, dorsally with 1 slender and 2 brush setae on each side, dorsolaterally with 1 stout and 1 short slender setae on one side only.

Etymology: This species is named after conservation biologist Francisco Pontual, in recognition for his efforts

directed towards habitat protection.The specific epithet, pontual , is to be used as a name in apposition.

Type locality: Lake Tong Tso, Qinghai-Tibetan Plateau, 32°10′0″N, 84°42′0″E.

Remarks: Gammarus pontual sp. nov. is herein assigned to Gammarus , whose diagnostic characters (cf., Zamanpoore et al., 2011) are readily recognized in the new species. They are as follow: head with truncated cephalic lateral lobe and small eyes ( Fig. 2A View Figure 2 ); antenna 1 with developed accessory flagellum ( Fig. 2B View Figure 2 ); antenna 2 without calceoli ( Fig. 2C View Figure 2 ); maxillae 1-2 ( Fig. 3A, C View Figure 3 , respectively) with mesial margins densely setose; coxa 4 posteriorly excavated ( Fig. 6C View Figure 6 ); gnathopod 2 ( Fig. 5A, B View Figure 5 ) larger than 1; pereopods ( Fig. 6 View Figure 6 A-E) with stout and slender setae; epimeral plates 2-3 ( Fig. 7B, C View Figure 7 ) posteroventral corner acute; rami of uropod 3 ( Fig. 7F View Figure 7 ) densely setose; telson ( Fig. 7G View Figure 7 ) cleft, lobes with stout and slender setae apically.

Four species group of Gammarus have been recognized from the Tibetan Plateau (viz. Hou & Li, 2018): (1) the G. lacustris G.O. Sars, 1863 species group, consisting of five species, defined by the uropod 3 inner ramus longer than half of the length of the outer ramus, and by having both rami covered with plumose setae; (2) the cave-dwelling group, encompassing two eyeless species; (3) the G. sinuolatus Hou & Li, 2004 species group composed of one species and characterized by the uropod 3 with both rami bearing long simple setae; and (4) G. kangdingensis Hou & Li, 2018 species group formed by seven species with rami of uropod 3 presenting few simple or plumose setae ( Hou & Li, 2018).

Gammarus pontual sp. nov. clearly belongs to the G. lacustris G.O. Sars, 1863 species group, which consists of five species: G. lacustris ; G. lasaensis Barnard & Dai, 1988 ; G. hongyuanensis Barnard & Dai, 1988 ; G. frigidus Hou & Li, 2004 ; and G. jaspidus Hou & Li, 2004 . The new species additionally resembles the species in the G. lacustris species group by presenting the following characters: truncated cephalic lateral lobe; weakly setose coxae 1-7; pyriform gnathopod 1 propodus; subrectangular gnathopod 2 propodus. However, Gammarus pontual sp. nov. differs from the above congeners as follows: from G. lacustris in having (character states in G. lacustris within round brackets) small eyes ( Fig. 2A View Figure 2 ) (vs medium size eyes); maxilla 2 ( Fig. 3C View Figure 3 ) strongly setose (vs moderately setose); short gnathopod 1 ( Fig. 4A, B View Figure 4 ) carpus, about 1.3 times longer than wide (vs 1.6 times longer than wide), propodus lateral margin without facial stout setae (vs facial stout setae formula 3-2-1-1); palm defined by 1 stout seta (vs palm defined by 2 stout setae); gnathopod 2 ( Fig. 5A, B View Figure 5 ) mesial margin with facial cluster of 3 stout setae near palmar corner (vs mesial side with only 1 stout seta); pereopods 5-7 ( Fig. 6 View Figure 6 C-E) with basis slen- der (vs basis robust); posterior margin of epimeral plate 1 ( Fig. 7A View Figure 7 ) produced into a short spine (vs posterior margin not produced); posteroventral spine of the epimeral plates 2-3 ( Fig. 7B, C View Figure 7 ) moderately projected and rather blunt (vs strongly projected and sharp); urosomites 1-3 ( Fig. 1 View Figure 1 B-D) dorsal stout setae formula: 2-2-2, 1-2-1, and 2-0-2 (vs formula 1-2-1, 1-2-1, and 1-0-1, respectively); telson ( Fig. 7G View Figure 7 ) dorsolateral margin with 1 stout seta (vs stout setae absent).

It differs from G. lasaensis in having (character states in G. lasaensis within round brackets): small eyes ( Fig. 2A View Figure 2 ) (vs large size eyes); antenna 2 ( Fig. 2C View Figure 2 ) without calceoli (vs calceoli present), gland cone straight (vs curved upwards); gnathopod 1 ( Fig. 4A, B View Figure 4 ) propodus mesial margin without facial stout setae (vs facial stout setae formula 3-2-1), palm defined by 1 stout seta and weakly armed (vs defined by 2 stout setae and strongly armed); gnathopod 2 ( Fig. 5A, B View Figure 5 ) palm lateral margin with only 1 stout seta medially (vs 3 stout setae); epimeral plate 1 ( Fig. 7A View Figure 7 ) posterior margin glabrous (vs posterior margin provided with 3 setae); epimeral plates 2-3 ( Fig. 7B, C View Figure 7 ) posteroventral corner sharply pointed in a moderate length (vs stronger length and more acute corner); urosomites 1-3 ( Fig. 1 View Figure 1 B-D) with dorsal stout setae formula: 2-2-2, 1-2-1, and 2-0-2 (vs formula 3-2-3, 3-2-3, and 3-2-3, respectively); length of telson ( Fig. 7G View Figure 7 ) exceeding the peduncle of uropod 3 (vs length of telson falling short of distal tip of the peduncle), telson apex with 2 stout setae on each side (vs 3-4 stout setae).

The following characters can be used to distinguish Gammarus pontual sp. nov. from G. hongyuanensis (characters for the later species within round brackets): small eyes ( Fig. 2A View Figure 2 ) (vs large size eyes); antenna 1 ( Fig. 2B View Figure 2 ) accessory flagellum 3-articulate (vs 4-articulate); antenna 2 ( Fig. 2C View Figure 2 ) without calceoli (vs calceoli present); coxae 1-4 ( Figs. 4A View Figure 4 , 5A View Figure 5 and 6A, B View Figure 6 ) with no more than 3 setae (vs usually with 3-6 setae); gnathopod 1 ( Fig. 4A, B View Figure 4 ) propodus lateral margin devoid of facial stout setae and palm weakly armed (vs facial stout setae formula 4-1-2 and palm strongly armed); gnathopod 2 ( Fig. 5A, B View Figure 5 ) mesial margin with 3 stout setae (vs 2 stout setae on margin); pereopod 6 ( Fig. 6D View Figure 6 ) basis rather straight (vs basis weakly sinuate); epimeral plate 1 ( Fig. 7A View Figure 7 ) posterior margin glabrous (vs with 4 setules on posterior margin); epimeral plate 2 ( Fig. 7B View Figure 7 ) posteroventral spine moderately project- ed (vs weakly projected); urosomites 1-3 ( Fig. 1 View Figure 1 B-D) dorsal stout setae formula: 2-2-2, 1-2-1, and 2-0-2 (vs formula: 2-2-2, 2-2-2, and 2-0-2, respectively); telson ( Fig. 7G View Figure 7 ) length exceeding the peduncle of uropod 3 (vs length of telson falling short of distal tip of the peduncle).

Gammarus pontual sp. nov. and G. frigidus can be separated from each other in that the former species (characters for the latter species within round brackets) possess smaller eyes ( Fig. 2A View Figure 2 ) (vs medium size eyes); the antenna 2 ( Fig. 2C View Figure 2 ) gland cone almost reaching to the apex of the third peduncular article (vs gland cone distinctly reaching to the apex), no calceoli in the flagellum (vs calceoli present); 6 short stout and 2 slender setae in the right maxilla 1 palp ( Fig. 3B View Figure 3 ) (vs palp with 5 stout and 1 slender setae); the inner plate of maxilla 2 ( Fig. 3C View Figure 3 ) with facial oblique row of 53 slender setae (vs row of only 32 plumose setae); the coxa 4 ( Fig. 6B View Figure 6 ) about 1.2 times longer than wide (vs coxa 4 as long as wide); the posterior margin of the gnathopod 1 ( Fig. 4A, B View Figure 4 ) propodus without stout setae (vs 9 stout setae on propodus); the gnathopod 2 ( Fig. 5A, B View Figure 5 ) carpus distinctly shorter than propodus, being about 0.7 times the length of propodus (vs carpus only slightly shorter than propodus) and acute palm (vs transverse palm); slender and long pereopods 5-7 ( Fig. 6 View Figure 6 C-E) basis (vs robust and short basis); the urosomites 1-3 ( Fig. 1 View Figure 1 B-D) not dorsally elevated and dorsal stout setae formula: 2-2-2, 1-2-1, and 2-0-2 (vs urosomites 1-2 slightly dorsally elevated and formula: 3-2-1-3, 3-2-3, and 2-0-2, respectively); 1 dorsal stout seta on the uropod 1 ( Fig. 7D View Figure 7 ) outer ramus (vs 3 dorsal stout setae); the telson ( Fig. 7G View Figure 7 ) apex provided with 2 stout setae on each side (vs telson apex with 3-4 stout setae on each side).

Gammarus pontual sp. nov. distinguishes itself from G. jaspidus by having (characters for the later species within round brackets) small eyes ( Fig. 2A View Figure 2 ) (vs medium size eyes); the antenna 2 ( Fig. 2C View Figure 2 ) flagellum without calceoli (vs some articles only with calceoli); the palp of the right maxilla 1 ( Fig. 3B View Figure 3 ) with 6 short stout and 2 slender setae (vs right maxilla 1 with 5 stout and 2 slender setae); the maxilla 2 ( Fig. 3C View Figure 3 ) inner plate with facial oblique row of 53 slender setae (vs 27 plumose setae); the posteri- or margin of the gnathopods 1-2 ( Figs. 4A, B View Figure 4 and 5A, B View Figure 5 ) propodus without stout setae (vs 10 and 6 stout setae on the gnathopods 1-2 propodus, respectively); the posteri- or margin of the pereopods 3-4( Fig.6A,B View Figure 6 ) meri with short to medium setae (vs meri with very long setae); the pleonites 1-3 not dorsally elevated and devoid of setae, (vs pleonites 1-3 weakly dorsally elevated and provided with several short setae); the pleopod 2 ( Fig. 8B View Figure 8 ) with 2 retinacula (vs pleopod 2 with 3 retinacula); the urosomites 1-3 ( Fig. 1 View Figure 1 B-D) not dorsally elevated and dorsal stout setae formula: 2-2-2, 1-2-1, and 2-0-2 (vs urosomites 1-2 elevated and dorsal stout setae formula: 3-3-1-3, 2-2-2, and 0-2-0, respectively); and the uropod 1 ( Fig. 7D View Figure 7 ) outer ramus with 1 dorsal stout seta (vs 3 stout setae).