Ctenorillo binomio Carpio-Díaz, Bichuette & Campos-Filho n. sp.

Figures 1-4

urn:lsid:zoobank.org:act: 3BD90801-12AA-4743-B4AC-75DC2996170C

Material examined

COLOMBIA: Holotype ♂ (parts in micropreparations) (CBUDC-CRU 412), Bolívar, Morales, Arcadia, San Miguel cave, 8°22’21.22”N 73°55’54.17”W, 20 April 2018, leg. C.M. López-Orozco and R. Borja-Arrieta . Paratype: 1 ♀ (parts in micropreparations) (CBUDC-CRU 337), same data as holotype .

Description

Maximum length: male and female 5 mm. Color dark gray. Dorsum covered with small triangular tubercles, arranged as follows (Figure 2A,B): cephalon with 10 tubercles in three rows, anterior and middle rows with two tubercles each, posterior row with six tubercles; pereonite 1 with four tubercles on anterior row, 12 tubercles on middle arranged in two rows of six tubercles each, and five tubercles on posterior row; pereonites 2-6 with eight tubercles on anterior row, and nine tubercles on posterior row; pereonite 7 with six tubercles on anterior row, and nine tubercles on posterior row; pleonites 3 and 4 with four tubercles, pleonite 5 and telson with two tubercles each. Dorsal surface with short triangular scale-setae (Figure 2C). Pereonites 1-7 with one line of noduli laterales per side inserted on postero-lateral surface of second outer tubercle. Cephalon (Figure 2 D-F) with frontal shield rectangular, slightly protruding above vertex, and slightly bent over vertex; eyes of 12 ommatidia. Pereonite 1 epimera slightly grooved on lateral margin for about half length, inner lobe of schisma rounded, not extending beyond posterior margins of outer lobe; pereonites 2-4 epimera rectangular, pereonite 2 with ventral lobe subtriangular, distal margin rounded, not extending beyond posterior margin of epimera (Figure 2A,F,G). Pleonites 3- 5 epimera rectangular (Figure 2H,I). Telson (Figure 2H) hourglass-shaped, proximal part broader than distal part, slightly convex distal margins. Antennula (Figure 2J) of three articles, proximal and distal articles subequal in length, distal article bearing seven apical aesthetascs. Antenna (Figure 2K) short and stout, not surpassing posterior margin of cephalon when extended backwards; flagellum of two articles, distal article about three times as long as proximal article, bearing two lateral aesthetascs; apical organ short. Mandibles with molar penicil semi-dichotomized bearing several plumose branches, left mandible (Figure 3A) with 2+1 penicils, right mandible (Figure 3B) with 1+1 penicils. Maxillula (Figure 3C) inner branch distal margin rounded bearing two long penicils; outer branch composed of 4+5 simple teeth. Maxilla (Figure 3D) bilobate, inner lobe covered with thick setae; outer lobe about three times as wide as inner lobe covered with thin setae. Maxilliped (Figure 3E) basis rectangular bearing sparse setae; palp proximal article with two distinct setae; endite subrectagular, medial seta strong, distal margin with two hook-like setae. Pereopod 1 carpus with antennal grooming brush transverse, and distal setae apically cleft; dactylus with ungual and dactylar seta simple. Uropod (Figure 3F) protopod trapezoidal, flattened, basal part enlarged, medial margin slightly concave; exopod short, inserted dorsally on distinct lobe near medial margin; endopod inner margin bearing fringe of setae. Pleopods 1-5 exopods with monospiracular lungs.

Male: Pereopod 1 and 7 (Figure 4A,B) with no particular modifications. Genital papilla as in Figure 4C. Pleopod 1 (Figure 4C) exopod subtriangular, slightly wider than long, outer margin slightly crenulate bearing five short setae; endopod three times as long as exopod, distal part tapering, and slightly bent outwards. Pleopod 2 (Figure 4D) exopod triangular, outer margin concave bearing eight short setae; endopod flagelliform longer than exopod. Pleopod 3 and 4 exopods as in Figure 4E and F, respectively. Pleopod 5 exopod (Figure 4G) rhomboid, outer margin slightly concave bearing many setae.

Etymology

The new species is named after the Vallenata music group "Binomio de Oro", dedicated to its singer and founder Rafael Orozco.

Remarks

In the arrangement of the dorsal tubercles of the pleon, Ctenorillo binomio n. sp. is similar to C. gabunensis and C. tuberosus; however, it can be distinguished in the shape, number and arrangement of the dorsal tubercles of the cephalon and pereon (see Schmalfuss and Ferrara 1983; Campos-Filho et al. 2017). Moreover, in comparison with the other Neotropical species, it differs in having the cephalon with 10 tubercles (vs. 12 in C. dazai and C. mineri; 14 in C. ferrarai), pereonite 1 with 21 tubercles (vs. 23 in C. dazai; 22 in C. ferrarai), pereonites 2-6 with 17 tubercles and pereonite 7 with 15 tubercles (vs. pereonites 2-7 with 15 tubercles in C. dazai; pereonites 2-7 with 12 tubercles in C. ferrarai), pleonites 3-5 composed of 4+4+2 tubercles (vs. 3+3+ 3 in C. dazai; 4+4+ 4 in C. ferrarai and C. mineri); antennula with seven aesthetascs (vs. six in C. dazai; eight in C. ferrarai), uropod exopod short inserted bellow the dorsal lobe (vs. tiny and inserted above the dorsal lobe in C. dazai and C. ferrarai), and male pleopod 1 exopod with the distal-medial part broad (vs. triangular in C. dazai and C. ferrarai) (see Vandel 1952; Campos-Filho et al. 2014; Carpio-Díaz et al. 2018).