Bemlos myersi, 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 : 454-456

Bemlos myersi sp. nov.

( Figures 2–6 )

Type material. Holotype, male (5.13 mm, dissected and drawn, 1 slide), MZUSP 45143 , PROTRINDADE, Trindade Island , off Espírito Santo, Brazil, Ponta Norte, artificial reef, 9.6 m depth, 20°29’18.7”S – 29°20’18.3”W, JB Mendonça coll., 26.v.2022.

Paratypes: 2 juvenile females (2.81 mm, dissected and drawn, 1 slide), MZUSP 46909 , same data as holotype . 1 subadult male (drawn, 4.56 mm), MZUSP 47524 , ibidem, 14.2 m, 20°29’18.7”S – 29°20’18.3”W, JB Mendonça coll., 02.vii.2016 . 2 subadult males (one drawn, 4.06 mm), MZUSP 46911 , ibidem, Praia do Noroeste, artificial reef, 1 m, 20°29’46.9”S – 29°20’35.4”W, JB Mendonça coll., 30.vii.2018 . 1 female (drawn, 4.21 mm), MZUSP 46912 , ibidem, Ponta Norte , in calcareous algae, 8.4 m, 20°29’18.7”S – 29°20’18.3”W, JB Mendonça coll., 26.v.2022 . 1 female (4.69 mm) 1 male (3.96 mm), MOUFPE 22052 , ibidem, Enseada dos Portugueses ( SECON), 10.2 m, 20°30’20.9”S – 29°18’43.7”W, JB Mendonça coll., 22.xi.2014 .

Type locality. Ponta Norte, 20°29’18.7”S – 29°20’18.3”W, 9.6 m, Trindade Island , off the coast of Espírito Santo, Brazil .

Distribution. So far only known from Trindade Island, between 1 m and 14.2 m.

Etymology. This species is named in honor of Dr. Alan A. Myers for his outstanding contributions on the taxonomy and phylogeny of the family Aoridae . He described almost 60% of the valid species of the genus Bemlos .

Diagnosis

Rostrum short, intrantennal process acute, upturned in male and female. Pereon with dark bands extending laterally on dorsum of head, pereonites 3-6 and pleonites 1-2. Pereonites with sternal spines, on segment 2 and 3 short, weakly acute, produced forward. Gnathopod 1 propodus ovate, 3.2x longer than carpus, 1.6x longer than broad, palm acute, with large triangular process followed by “U”-shaped excavation; palmar corner defined by a large triangular process bearing robust seta. Uropod 1 peduncle subequal to rami; interramal spine robust, 0.3x of peduncle length; rami subequal in length. Uropod 2 peduncle 0.8x of outer ramus length; interramal spine robust, 0.4x length of peduncle; inner ramus longer than outer ramus. Uropod 3 peduncle 1.4x longer than broad; rami subequal to each other and moderately long, 1.8x longer than peduncle.

Description. Based on holotype.

Head. Rostrum short, intrantennal process acute, upturned. Lateral cephalic lobes rounded, eyes of medium size, dark.Antennae missing. Maxilla 2 outer and inner plates subequal; inner plate with oblique setal row. Mandible palp article 1 0.5x of article 2 length, lacking setae; article 2 with long setae on inner margin; article 3 longer than article 2 (1.4x), outer and inner margins with long setae; left mandibular molar primary plate falcate.

Pereon. Color (in alcohol): dark bands extending laterally on dorsum of head, pereonites 3-6 and pleonites 1- 2. Peronites with sternal spines, on segment 2 and 3 short, weakly acute and produced forward. Gnathopod 1 coxa subrectangular, 1.9x wider than deep; basis to propodus covered with small tubercles; basis very stout, about 1.5x longer than broad; ischium with short seta on posterodistal angle; merus 2x longer than ischium, posterior margin with tuft of setae; carpus 1.5x broader than long, posterior margin subtriangular with tuft of long setae; propodus ovate, 3.2x longer than carpus, 1.6x longer than broad, palm acute, with large triangular process followed by “U”- shaped excavation; palmar corner defined by a large triangular process bearing robust seta; dactylus elongate, overlapping palm. Gnathopod 2 coxa subrectangular, 1.5x wider than deep; basis elongate, slender, 2.7x longer than broad, anterior margin weakly concave, posterior margin convex; carpus elongate, 2.7x longer than broad, anterodistal and posterior margins clothed in dense, long setae; propodus reaching 1.8x of carpus length, palm evenly convex, finely serrate, palmar corner with a robust seta; dactylus curved, fitting palm. Pereopods 3-4 similar to each other, coxae wider than deep, basis slender, subequal to ischium, merus and carpus together, anterior margin with some short setae, posterior margin with some long setae; propodus lined with long setae on posterior margin; dactylus about 0.4x of propodus length. Pereopod 5 basis 2.1x longer than wide, with short setae on both anterior and posterior margins, merus slightly longer than propodus, with tuft of long setae on anterodistal angle; propodus with long setae on anterior margin, dactylus short. Pereopod 6 basis 2.3x longer than wide, with short setae on anterior margin, posterior margin with short and long setae; merus longer than carpus (1.5x), with some long setae on posterior margin; propodus 5.6x longer than wide, with long setae on anterior margin, dactylus short. Pereopod 7 missing.

Pleon. Epimera 2- 3 with short spine and short seta on posteroventral angle. Uropod 1 peduncle subequal to rami, inner margin with two robust setae, outer margin with three robust setae; interramal spine robust 0.3x of peduncle length; rami subequal in length; outer ramus with four marginal robust setae, apically with five robust setae; inner ramus with five marginal robust seta, apically with four robust setae. Uropod 2 peduncle 0.8x of outer ramus length, inner margin with two long robust setae, outer margin with one robust seta; interramal spine robust, 0.4x length of peduncle; inner ramus longer than outer ramus, with three marginal robust setae, apically with four robust setae; outer ramus with five marginal robust setae, apically with five robust setae. Uropod 3 peduncle 1.4x longer than broad; rami subequal to each other and moderately long, 1.8x longer than peduncle; outer ramus with four slender marginal setae, apically with three slender setae; inner ramus with three slender marginal setae, apically with four slender setae. Telson 1.3x longer than wide, with two short setae on lateral margins and two pairs of long setae on dorsal crest, distal margin with rounded process.

Female (sexually dimorphic characters only)

Gnathopod 1 coxa almost as long as wide, basis moderately inflated, 2.5x longer than wide, posterior margin with two long slender setae; carpus shorter than propodus (0.6x); propodus subovate, anterior and posterior margins with slender setae, 1.9x longer than wide, palm acute, with crenulated shallow rounded process, palmar corner defined by a subacute process, bearing long and robust setae; dactylus slightly overreaching palm, inner margin with six subacute spines. Gnathopod 2 coxa slightly longer than wide (1.2x); basis slender, 3x longer than wide, anterior margin with slender setae; ischium with two setae; carpus subtriangular, distally widened, 1.9x longer than wide; propodus subequal to carpus, subrectangular, palm almost transverse, palm finely serrate, palmar corner with a long and robust seta; dactylus fitting palm, inner margin with four subacute spines.

Figures

FIGURE 2. Bemlos myersi sp. nov. Habitus and mouthparts, holotype (5.13 mm), Trindade Island, off Espírito Santo, Brazil, 9.6 m depth, 20°29’18.7”S–29°20’18.3”W, 26.v.2022, MZUSP 45143. Abbreviations: Hb, habitus, Hd, head; IS, intrantennal spine; Md, mandible. Scale bars = 0.5 for habitus and 0.1 mm for the remains.

FIGURE 3. Bemlos myersi sp. nov. holotype (5.13 mm), gnathopods 1–2, Trindade Island, off Espírito Santo, Brazil,9.6 m depth, 20°29’18.7”S–29°20’18.3”W, 26.v.2022, MZUSP 45143. Abbreviations: G, gnathopod. Scale bars = 0.1 mm.

FIGURE 4. Bemlos myersi sp. nov. Paratypes: female (4.21 mm), Head, gnathopod 1-2, Trindade Island, off Espírito Santo, Brazil, Ponta Norte, 8.4 m, 20°29’18.7”S–29°20’18.3”W, 26.v.2022, MZUSP 46912. Subadult male 1 (4.06 mm), gnathopod 1, ibidem, Praia do Noroeste, artificial reef, 1 m, 20°29’46.9”S–29°20’35.4”W, 30.vii.2018, MZUSP 46911. Subadult male 1 (4.56 mm), ibidem, 14.2 m, 20°29’18.7”S–29°20’18.3”W, 02.vii.2016, MZUSP 47524. Abbreviations: Hd, head; IS, intrantennal spine; G, gnathopod; f, female; m, male; Sub, subadult. Scale bars = 0.1 mm.

FIGURE 5. Bemlos myersi sp. nov. holotype (5.13 mm), pereopods 3-6, Trindade Island, off Espírito Santo, Brazil, 9.6 m depth, 20°29’18.7”S–29°20’18.3”W, 26.v.2022, MZUSP 45143. Abbreviations: P, pereopod. Scale bars = 0.1 mm.

FIGURE 6. Bemlos myersi sp. nov. holotype (5.13 mm), pereonites 1-3, epimera 2-3, uropods 1-3, telson, Trindade Island, off Espírito Santo, Brazil, 9.6 m depth, 20°29’18.7”S–29°20’18.3”W, 26.v.2022, MZUSP 45143. Abbreviations: Ep, epimeron; Pr, pereonite; T, telson; Ur, uropod. Scale bars = 0.1 mm.