Globosolembos trindadensis, Guedes-Silva & Souza-Filho & Tavares, 2025

Guedes-Silva, Elkênita, Souza-Filho, Jesser F. & Tavares, Marcos, 2025, The Amphipoda of the remote oceanic archipelago Trindade and Martin Vaz (Brazil). II. Five new species of shallow-water aorid and photid amphipods (Senticaudata: Corophiida), Zootaxa 5659 (4), pp. 451-482 : 461-466

Globosolembos trindadensis sp. nov.

(Figures 7–10)

Type material. Holotype, male (3.23 mm, dissected and drawn, 1 slide), MZUSP 46913 , PROTRINDADE, Trindade Island , off Espírito Santo, Brazil, Ponta da Calheta, 16.6 m, 20°30’18.7”S – 29°19’31.6”W, JB Mendonça coll., 08.v.2014.

Paratypes: 1 female (2.89 mm, dissected and drawn, 1 slide) and 2 individuals (2.23 mm e 3.68 mm), MZUSP 46914 , same data as holotype . 1 male, MZUSP 46915 , ibidem, Enseada dos Portugueses, Farol , 13.3 m, 20°29’52.3”S - 29°19’15.6”W, J.B. Mendonça, coll., 17.iv.2012 . 1 male, 1 female, MOUFPE 22053 , ibidem, 14.6 m, J.B. Mendonça coll., 10.vii.2012 . 1 male, 2 females, ibidem, MZUSP 46916 . 1 male, 4 females, MZUSP 46917 , ibidem, Praia dos Portugueses (Rampa nova), 11 m, 20°30’17.7”S - 29°18’56.7”W, J.B. Mendonça coll., 23.iv.2014 . 1 female, MZUSP 46918 , ibidem, Enseada da Praia do Príncipe, Ilha Sul, 18 m, 20°31’34.22”S - 29°19’27.9”W, J.B. Mendonça coll., 06.xi.2014 .

Type locality. Ponta da Calheta , 20°30’18.7”S – 29°19’31.6”W, 16.6 m, Trindade Island, off Espírito Santo, Brazil .

Distribution. So far only known from Trindade Island, between 11 m and 18 m.

Etymology. It is named in reference to the type locality, Trindade Island.

Diagnosis. Rostrum short, intrantennal process absent. Head anteroventral margin weakly excavated, anteroventral angle produced into short spine. Pereon not pigmented. Pereonites 2-5 with sternal spines, on segment 2 slender, subacute and directed backward, on segments 3-5 large and blunt. Gnathopod 1 basis to propodus smooth; basis moderately stout, about 1.8x longer than broad; carpus subquadrate, 1.2x longer than broad, posterior margin with long setae; propodus ovate, 1.6x longer than carpus, 1.5x longer than broad, palm acute, palmar corner defined by a short spine and a robust seta. Gnathopod 2 basis elongate, slender, 2.5x longer than broad, anterior margin weakly concave; carpus elongate, 1.8x longer than broad, anterodistal and posterior margins with long setae; propodus subequal in length to carpus, anterodistal and posterior margins with long setae, palm evenly convex, finely serrate, palmar corner with robust seta; dactylus curved, fitting palm. Uropod 1 peduncle subequal to rami; interramal spine 0.3x of peduncle length; rami subequal in length. Uropod 2 peduncle subequal in length to rami; interramal spine 0.2x length of peduncle; inner and outer rami with midway marginal robust seta, apically with three robust setae. Uropod 3 peduncle 1.4x longer than broad; outer ramus longer than inner ramus.

Description. Based on holotype.

Head. Rostrum short, intrantennal spine absent. Lateral cephalic lobes subquadrate; eye of medium size, dark. Anteroventral margin weakly excavated, anteroventral angle produced into short spine. Antennae missing. Maxilla 2 outer and inner plates subequal; inner plate with oblique setal row. Mandible palp article 1 0.4x of article 2 length and lacking setae; article 2 with long setae on inner margin; article 3 longer than article 2 (1.2x), inner margin with long setae.

FIGURA 7. Globosolembos trindadensis sp. nov. holotype (3.23 mm), Habitus, head; mouthparts, pereonites 1-5, Trindade Island , off Espírito Santo, 16.6 m, 20°30’18.7”S – 29°19’31.6”W, 08.v.2014, MZUSP 46913 . Abbreviations: Hb, habitus, Hd, head; Md, mandible, Pr, pereonite. Scale bars = 0.5 for habitus and 0.1 mm for the remains .

Pereon. Not pigmented (in ethanol). Pereonites 2-5 with sternal spines, on segment 2 slender, subacute and directed backward, on segments 3-5 large and blunt. Gnathopod 1 coxa ovate, 1.8x wider than deep; basis to propodus smooth; basis moderately stout, about 1.8x longer than broad; ischium with tuft of setae on posterior margin; merus with line of setae on posterior margin; carpus subquadrate, 1.2x longer than broad, posterior margin with long setae; propodus ovate, 1.6x longer than carpus, 1.5x longer than broad, palm acute, palmar corner defined by a short spine and a robust seta; dactylus fitting palm. Gnathopod 2 coxa subrectangular, 1.3x wider than deep; basis elongate slender, 2.5x longer than broad, anterior margin weakly concave, posterior margin convex; carpus elongate, 1.8x longer than broad, anterodistal and posterior margins with long setae; propodus subequal in length to carpus, anterodistal and posterior margins with long setae, palm evenly convex, finely serrate, palmar corner with robust seta; dactylus curved, fitting palm. Pereopods 3-4 similar to each other, coxae wider than deep, basis slender, shorter than ischium, merus and carpus together, anterior margin with some short setae, posterior margin with some long setae; propodus with long setae on posterior margin, and robust setae subdistally; dactylus about 0.5x of propodus length. Pereopod 5 basis 1.9x longer than wide, with short setae on both anterior and posterior margins, carpus slightly longer than propodus, with 2 long setae on posterodistal angle; propodus with long setae on anterior margin, dactylus short. Pereopod 6 basis 2.3x longer than wide, with 3 short setae on anterior margin, posterior margin with short and long setae; merus longer than carpus (1.4x), with some long setae on posterior margin; propodus 6.2x longer than wide, with 2 long setae on anterior margin, dactylus short. Pereopod 7 very long, about 3.0x longer than pereopod 5, basis longer than wide (2.3x), posterior margin with long setae; merus 0.7x propodus length; carpus subequal to merus length; propodus with tuft of long setae on posterodistal angle.

Pleon. Epimera 1-3 rounded.Uropod 1 peduncle subequal to rami, with two robust setae on distal third; interramal spine robust 0.3x of peduncle length; rami subequal in length; outer ramus without marginal setae, apically with three robust setae; inner ramus with one marginal robust seta, apically with three robust setae. Uropod 2 peduncle subequal in length to rami, with one marginal robust seta; interramal spine robust, 0.2x length of peduncle; inner and outer rami with midway marginal robust setae, apically with three robust setae. Uropod 3 peduncle 1.4x longer than broad; outer ramus longer than inner ramus, with a robust and a long slender seta distally, 1.4x longer than peduncle; inner ramus with four slender setae apically; outer ramus with four slender and marginal setae, apically with four slender setae. Telson almost as long as wide, with two long setae on dorsal crest, distal margin rounded.

Female (sexually dimorphic characters only)

In Globosolembos trindadensis sp. nov., females and males resemble each other, differing only in the less setose gnathopod 2 and in the absence of sternal processes on the pereonites.

Remarks. Globosolembos smithi ( Holmes, 1905) is the only species from the genus previously recorded from Brazilian waters so far ( Valério-Berardo & Miyagi 2000). The new species differs from G. smithi as follows (characters of G. smithi within brackets): anteroventral margin of head weakly excavated (vs. margin strongly excavated), anteroventral angle of head produced into a short spine (vs. angle of head produced into a large and acute spine), palms of both male and female gnathopod 2 almost straight (vs. palm sinuous); propodus of gnathopod 2 1.7x of carpus length (vs. 2x or more of carpus length); pereopod 7 very long, about 3.0x longer than length of pereopod 5 (vs. 2x or less in length); outer ramus of uropod 1 marginally naked, inner ramus with one marginal seta (vs. both rami with two lines of 4-5 robust setae); rami of uropod 2 with only one marginal robust seta each (vs. rami with tree robust setae each); and, ramus of uropod 3 setae distally only (with marginal and distal setae).

Globosolembos trindadensis sp. nov. superficially resembles G. tiafaui Myers, 1985 from Upolu Island, Western Samoa, in the poorly developed anteroventral corner of head, subovate article 3 of mandibular palp, palm of gnathopods 1-2 almost straight, and poorly setose rami of uropods 1-3. Nevertheless, the two species can be distinguished as follows (characters for G. tiafaui within brackets): propodus of the gnathopod 2 1.7x longer than carpus (vs. carpus and propodus subequal in length); sternal ventral processes on the pereonites 3-5 triangular and well-developed (vs. process on pereonite 3 well-developed and subacute, on pereonites 4-5 poorly developed and rounded); peduncle of uropod 2 with an acute interramal process (vs. lacking interramal process); and inner and outer rami of uropod 3 subequal in length (vs. outer ramus about 1/2 of inner ramus).