Skuphonura oaxaquensis Jarquín-Martínez & García-Madrigal 2021, sp. nov.
Creators: name: Jarquín-Martínez, Ubaldo
name: García-Madrigal, María del Socorro
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Isopoda
Anthuridae
Skuphonura
Skuphonura oaxaquensis

description: Skuphonura oaxaquensis sp. nov.
urn:lsid:zoobank.org:act: 5739A519-7093-496A-8F3C-9EEAC092E241
Figs 14– 16, 20E, Table 2
Etymology
This species is named after Oaxaca, the Mexican State where the specimens were collected.
Material examined
Holotype MEXICO • ♀ (body length 7.9 mm); Oaxaca, Puerto Ángel, Estacahuite Beach; 15°40′ N, 96°29′ W; depth 2–4 m; 10 Sep. 2005; J.R. Bastida-Zavala et al. leg.; coral rock; UMAR-PERA 548.
Paratypes MEXICO • 1 ♂ (body length 7.3 mm); same collection data as for holotype; UMAR-PERA 549 • 12 ♀♀, 1 ♂; same collection data as for holotype; UMAR-PERA 550.
Description
Holotype (♀, UMAR-PERA 548)
BODY (Figs 14A–B, 20E). Length 7.9 mm, 8.4 times as long as wide with pigment in the cephalon and margins of each somite; body proportion: C<1>2≥3<4>5>6>7. Cephalon 1.2 times as long as wide, rostrum as long as the lateral angles of cephalon, base of the mouthparts with two sharp spines. Pereonite 7 rectangular, 1.3 times as wide as long; pleonites 1–5 fused, broadened distally, slightly longer than pereonite 7; telson linguiform, narrow distal region, mid-distal region with a group of seven setae, apex slightly excavated with three pairs of setae; a pair of the statocysts.
ANTENNULE (Fig. 14D). Peduncle with three articles. Articles 1 and 2 with plumose sensory setae; article 2 rectangular, slightly more than half the length of the first with six long distolateral setae; article 3 sub-equal in length to second with one long seta in the external distal angle and two in the internal one; flagellum with three articles, last tiny article with three aesthetascs and two smooth setae.
ANTENNA (Fig. 14E). Peduncle with five articles. Article 2 with ventrodistal angle projected to article 3; flagellum with four articles with numerous thin setae.
MAXILLIPED (Fig. 14F). Palp with three articles; article 1 with concave external margin; article 2 larger to the others with sinuous internal margin; distal article subcircular with a row of distal setae.
MAXILLA (Fig. 14G). With eight distal teeth.
MANDIBLE (Fig. 14H). Symmetrical; palp with three articles, article 1 sub-equal in length to the second with a long pectinate seta; article 2 with three pectinate setae and setulated scales in dorsal margin; article 3 small, 0.4 times as long as second, with four distal setae; incisor with four teeth; lacinia mobilis with 11 denticles and molars with two rounded tubercles.
PEREOPOD 1 (Fig. 15A). Subchelate; basis with dorsodistal angle lobate; carpus subtriangular, distal angle projected transversally; palm concave with a strong proximal tooth; proximal margin with six setae, distal margin with eight setae; internal margin of dactylus slightly concave with a cuticular ridge; unguis slightly more than half the length of dactylus with a slight curvature distally.
PEREOPODS 2–3 (Fig. 15B–C). Similar in shape and size. Merus internal margin with cuticular ridges and numerous setae; carpus triangular, distal margin with a denticulate seta; palm with numerous setae and setulated scales, ventral angle with a denticulate sensory spine and a group of smooth setae.
PEREOPODS 4–6 (Fig. 15D–F). Similar in shape and size. Merus margin with cuticular ridges; carpus subtriangular, truncated distally with a simple sensory spine and simple setae; propodus cylindrical, 2–2.1 times as long as wide in P4 and P5, 2.3 in P6, internal margin with setulated scales and simple setae, ventrodistal angle with a denticulate sensory spine and simple setae.
PEREOPOD 7 (Fig. 15G). Slenderer than the preceding ones, propodus 3.3 times as long as wide, ventrodistal margin with setulated scales and one denticulate sensory spine and two pectinate spines; lateral margins of dactylus with setulated scales.
PEREOPODS 2–7. With smooth and plumose sensory setae at the basis.
PLEOPOD 1 (Fig. 16A). Protopod with three retinaculae; exopod operculiform, 2.2 times as long as wide, surrounded distally by 40 plumose setae; endopod 0.7 times the length of exopod, surrounded distally by five plumose setae.
PLEOPOD 2 (Fig. 16B). Oval and elongated; exopod 2.8 times as long as wide, surrounded distally by 12 plumose setae; endopod slightly shorter than exopod, surrounded distally by eight plumose setae.
UROPODAL PROTOPOD (Fig. 16C). Rectangular, 1.7 times as long as wide, 1.2 times as long as endopod, external margin with plumose setae, ventrodistal angle with a long seta.
UROPODAL ENDOPOD (Fig. 15C). Conical, 1.9 times as long as basal width, apically rounded, external margin with numerous long setae.
UROPODAL EXOPOD (Fig. 16D). Suboval with a distal notch, margin with 17 long smooth setae and approximately 55 plumose setae.
Male (dimorphic characters; based on the paratype ♂, UMAR-PERA 549)
BODY. Mid-region of the cephalon (Fig. 14C) with a poorly developed spine.
ANTENNULE (Fig. 16E). Peduncle with three articles; article 1 and 2 with plumose sensory setae; article 2 with six long setae in the external distal angle; flagellum with nine articles, distal article with three aesthetascs.
PEREOPOD 1 (Fig. 16F). Subchelate; carpus triangular, distally produced in a narrow triangular process; propodus oval, palm straight with a triangular proximal process, accompanied by eight setae; dactylus 1.4 times as long as unguis, distoventral angle with a small spine.
PLEOPOD 2 (Fig. 16G). Endopod and exopod sub-equal in length; exopod surrounded distally by 11 plumose setae; endopod surrounded distally by seven plumose setae; male appendix thin, longer than the branches, emerging from the middle proximal part of the endopod, ending in a pointed apex.
Distribution and habitat
Known only from the type locality, Estacahuite Beach, Oaxaca. In coral rock; subtidal (4 m).
Remarks
Skuphonura oaxaquensis sp. nov., and three other species of genus: S. kensleyi Brusca & Müller, 1991, S. itapuca Kensley, 1980 and S. lindae Menzies & Kruczynski, 1983 (Table 2), share the following two characters: anterior margin of the cephalon as wide as the posterior margin and the anterolateral lobes are sub-equal to the rostral process, while in S. ecuadorensis Kensley, 1980 and S. laticeps Barnard, 1925, the anterior margin of the cephalon is wider than the posterior and the lobes are longer than the rostral process.
Skuphonura itapuca, described from Nichteroy, Rio de Janeiro, Brazil, is the closest species to S. oaxaquensis sp. nov. by the following characteristics: (1) absence of a mid-ventral spine in the pereonite 1, (2) mid-ventral region of cephalon with two processes, (3) second article of mandibular palp with three long setae. However, in S. oaxaquensis sp. nov. the body is partially pigmented, cephalon slightly wider medially, flagellum of antennule with three articles, distal article with three aesthetascs, flagellum of antenna with four articles, and carpus of pereopod 1 is externally projected and palm with one proximal tooth; while, S. itapuca lacks pigment, anterior margin of the cephalon is slightly wider than the posterior, flagellum of antennule with two article and two distal aesthetascs, flagellum of antenna with one article, carpus of pereopod 1 projected apically and palm with one proximal and one distal spine.
Skuphonura oaxaquensis sp. nov. and S. kensleyi, described from Santa Marta, Punta de Betín, Colombian Caribbean, are similar by the following characteristics: (1) pigmentation pattern, (2) cephalon slightly wider medially, (3) antennular flagellum, (4) carpus of pereopod 1. However, in S. kensleyi the pereonites and pleon have reticulated pigmentation, antennular flagellum with one aesthetasc, antennal flagellum with one article, the second article of the mandibular palp with two distal setae and three proximal setae, lacinia mobilis with six denticles, and palm of the pereopod 1 has a medial tooth; while, in S. oaxaquensis sp. nov. the reticulated pigmentation is partial in pereonite 4 and pleon.
Skuphonura oaxaquensis sp. nov. differs from the preceding species by the following unique characteristics: (1) body pigmentation, (2) last article of mandibular palp with four setae, (3) lacinia mobilis with 11 denticles, (4) inner margin of the second article of maxillipedal palp sinus, and (5) palm of pereopod 1 with a proximal tooth.
description: Published as part of Jarquín-Martínez, Ubaldo & García-Madrigal, María del Socorro, 2021, Six new species of Anthuridae (Peracarida: Isopoda) from the southern Mexican Pacific, pp. 61-100 in European Journal of Taxonomy 760 (1) on pages 85-91, DOI: 10.5852/ejt.2021.760.1441, http://zenodo.org/record/5121764