Trichorhina navasi López-Orozco, Carpio-Díaz and Campos-Filho, 2021

Trichorhina navasi López-Orozco, Carpio-Díaz and Campos-Filho View in CoL n. sp.

( Figs. 1–4 View Figure 1 View Figure 2 View Figure 3 View Figure 4 )

Zoobank: urn:lsid:zoobank.org:act:62B2BAF2-7025-4B1D-8691-F3BCF3F3574A

Type material. Holotype: male (ICN-CR-is 178), Colombia, Department of Norte de Santander, La Playa de Belén, Área Natural Única ( ANU) Los Estoraques , Vereda Rosa Blanca , Sendero la Honda , 8°13’14 43” N 73°14’32 47”W, 1500 a.s.l., 04.XI.2013,leg. C. Romero and E. Flórez. Paratypes: 1 male (parts in micropreparations), (ICN-CR-is 178), same data as holotype .

Diagnosis. Body narrow, pereonites 1–7 with lateral sides almost parallel, eyes composed of ten ommatidia, cephalon with frontal line straight, male pleopod 1 exopod ovoidal,twice wider than long and distal margin sinuous, endopod elongate with distal margin acute.

Description. Maximum body length: 2.41mm. Body convex, outline as in Fig.1A, B View Figure 1 . Color light brown; antennal peduncle, median portion of pereon and pleon strongly pigmented; cephalon, antenna, and uropods with irregular unpigmented spots; pereon with unpigmented areas on paramedian portions ( Fig. 1A View Figure 1 ). Dorsal surface scaled, covered with fan-shaped scale-setae ( Fig. 1C View Figure 1 ). Body ( Fig. 1B View Figure 1 ) narrow, pereonites 1–7 with lateral sides almost parallel; pereonite 1 epimera directed frontwards, 2–7 progressively directed backwards. Pereonites 1–7 epimera with one line of small noduli laterales, inserted close to posterior margins and shifted from lateral margins; d/c and b/c coordinates as in Fig. 1D,E View Figure 1 . Cephalon ( Fig. 1A, B, F View Figure 1 ) with triangular lateral lobes, slightly directed outwards; suprantennal line straight; eyes composed of ten ommatidia strongly pigmented. Pleon slightly narrower than pereon, epimera 3–5 well developed and falciform ( Fig. 1A, B View Figure 1 ). Telson ( Fig. 1G View Figure 1 ) triangular with lateral margins concave, apex narrow with distal margin rounded. Antennula ( Fig. 1H View Figure 1 ) with articles subequal in length, distal article bearing two subapical plus three apical aesthetascs. Antenna ( Fig. 1I View Figure 1 ) when extended posteriorly reaching posterior margin of pereonite 1; distal article of flagellum three times longer than first, with two aesthetascs on proximal portion; apical organ short.Mandibles with molar penicil consisting of seven branches, left mandible ( Fig. 2A View Figure 2 ) with 2+1 penicils, right mandible ( Fig. 2B View Figure 2 ) with 1+1 penicils. Maxillula ( Fig. 2C View Figure 2 ) inner endite with two penicils; outer endite with 4+4 teeth, inner set with two teeth cleft at apex. Maxilla ( Fig. 2D View Figure 2 ) inner lobe subquadrangular, distal margin slightly rounded and covered with thick setae; outer lobe about three times as wide as inner lobe, covered with thin setae. Maxilliped ( Fig. 2E View Figure 2 ) basis rectangular bearing sparse scale-setae; palp with two setae distinct in length on proximal article; endite with medial seta surpassing distal margin.Pereopod 1 ( Fig. 3A View Figure 3 ) merus with sternal setae sparse; carpus with brush of setae on sternal margin and transverse antennal grooming brush; merus,carpus, and propodus with sternal setae double-serrate at apex. Pereopod 7 ( Fig. 3B View Figure 3 ) without any particular modification. Dactylus with inner claw not surpassing outer claw; ungual seta and dactylar organ simple, not surpassing outer claw ( Fig. 3A View Figure 3 ). Uropod ( Fig. 2F View Figure 2 ) protopod and exopod grooved on outer margin bearing glandular pores, protopod subrectangular, exopod slightly longer than endopod, endopod inserted proximally. Genital papilla( Fig.3C View Figure 3 )with triangular ventral shield and two subapical orifices. Pleopod1 ( Fig. 3D View Figure 3 )exopod ovoidal, twice as broad as long, distal margin slightly sinuous; endopod five times longer than exopod, distal portion acute. Pleopod 2 ( Fig. 3E View Figure 3 ) exopod triangular, outer margin concave bearing many small setae; endopod flagelliform, distinctly longer than exopod, distal portion slender. Pleopods 3–5 exopods as in Fig. 3F–H View Figure 3 .

Etymology. The new species is named after Dr. Gabriel R. Navas, from the University of Cartagena, Colombia, for his contributions to the knowledge of crustaceans from Colombia.

Remarks. In having the eyes composed of ten ommatidia, T. navasi n. sp. is similar to T. bermudezae (see Carpio Díaz et al.,2018), Trichorhina amazonica Souza-Kury, 1997 , Trichorhina mariani Arcangeli, 1930 , Trichorhina pubescens ( Dollfus, 1893) , and Trichorhina yiara Campos-Filho, Araujo and Taiti, 2014 ; however, it can be easily distinguished by the shape of the male pleopod 1. Moreover, it differs in having the eyes composed of ten ommatidia (vs. five to six in T. papillosa ), antennula with three apical aesthetascs plus two subapical (vs. five subapical in T. amazonica ; two apical plus two subapical in T. bermudezae ; four to five in T. papillosa ; four apical in T. yiara ), mandibles with molar process of seven branches (vs. four in T. amazonica ; five in T. bermudezae and T. yiara ; three in T. papillosa ), maxillula outer endite of 4+4 teeth, two teeth cleft at apex (vs. 3+4 with two cleft in T. amazonica and T. papillosa ; 5+4 and all simple in T. bermudezae ; 4+4 with two cleft in T. yiara ), and male pleopod 2 endopod with distal portion slender (vs. thicker in T.amazonica and T. yiara ) (see also Vandel, 1952; Souza-Kury, 1997; Campos-Filho et al., 2014; Carpio-Díaz et al., 2018). Comparisons with T. mariani and T. pubescens are limited because the available descriptions do not provide enough information.

The present work represents the first record of a terrestrial isopod in the Department of Norte de Santander ( Fig. 4 View Figure 4 ). Moreover, it describes the first species of Trichorhina in the Eastern Cordillera (up to 1500 m a.s.l.) pre-montane dry forest. Considering the diversity of the genus in other countries of the Neotropical region (e.g., Schmidt, 2001; Schmalfuss, 2003; Campos-Filho et al., 2018), the knowledge of the biodiversity of Trichorhina in Colombia is far from complete.