Amakusanthura guerrerensis sp. nov.

urn:lsid:zoobank.org:act: B887EED9-16EB-433E-9F69-ACD26CA84B62

Figs 2–4, 20A

Etymology

This species is named after Guerrero, the Mexico State where the type material was collected.

Material examined

Holotype MEXICO • ♀ (body length 5 mm); Guerrero, Ixtapa Island, Coral Beach, E-1A; 17°40′38″ N, 101°39′20″ W; depth 1.5 m; 19 Sep. 2007; M.S García-Madrigal et al. leg.; coral rock; UMAR- PERA 522.

Paratypes MEXICO • 2 ♀♀ (ovigerous), 4 ♀♀, 2 mancae; same collection data as for holotype; UMAR-PERA 523 .

Additional material

MEXICO – Guerrero • 4 ♀♀, 5 mancae; Ixtapa Island, Coral Beach, E-1B; 17°40′38″ N, 101°39′20″ W; depth intertidal; 19 Sep. 2007; M.S García-Madrigal et al. leg.; algae; UMAR-PERA 524 • 7 ♀♀, 7 mancae; Ixtapa Island, Coral Beach; 17°40′36″ N, 101°39′22″ W; depth 6 m; 19 Sep. 2007; M.S. García-Madrigal et al. leg.; coral; UMAR-PERA 525 • 4 ♀♀, 1 manca; Acapulco, La Roqueta Island; 16°49′26″ N, 99°54′29″ W; depth 2 m; 21 Sep. 2007; M.S. García-Madrigal et al. leg.; tubes of sabellariids; UMAR-PERA 526 . – Oaxaca • 1 ♀; Cozoaltepec, Agua Blanca Beach; 15°44′2″ N, 96°48′32″ W; depth intertidal; 11 Nov. 2007; I. López-Aguilar et al. leg.; algae; UMAR-PERA 527 • 3 ♀♀, 1 manca; Puerto Ángel, Estacahuite Beach; 15°40′ N, 96°29′ W; depth 0.5 m; 3 Jul. 2007; J. Jarquín-González et al. leg.; coral; UMAR-PERA 528 • 2 ♀♀ (ovigerous), 6 ♀♀, 1 ♂, 2 mancae; Pochutla, La Tijera Beach; 15°41′33″ N, 96°26′33″ W; depth 2–4 m; 30 Apr. 2005; J.R. Bastida-Zavala et al. leg.; coral rock; UMAR-PERA 529 • 1 ♀, 1 manca; Pochutla, La Tijera Beach; 15°41′33″ N, 96°26′33″ W; depth 3 m; 7 Apr. 2009; F. Cortés-Carrasco et al. leg.; coral rock; UMAR-PERA 530 • 5 ♀♀; Huatulco, San Agustín Bay; 15°41′27″ N, 96°14′15″ W; depth intertidal; 24 Feb. 2007; M.S. García-Madrigal et al. leg.; coral algae; UMAR-PERA 531 • 3 ♀♀; Huatulco, San Agustín Bay; 15°41′22″ N, 96°14′14″ W; depth intertidal; 24 Oct. 2013; H. Solano-García leg.; coral rock; UMAR- PERA 532 • 1 ♀; Huatulco, Cacaluta Bay; 15°43′21″ N, 96°9′48″ W; depth shallow water; 27 Oct. 2013; R. Rodríguez leg.; Spondylus shells; UMAR-PERA 533 .

Description

Holotype (♀, UMAR-PERA 522)

BODY (Figs 2A, 4E, 20A). Length 5 mm, about 10 times as long as wide with a brown pigment band at the posterior margin of the pereonites 3–7 and pleonite 5; moderately setose caudal region; body proportion: C<1=2=3<4>5<6>7. Subcircular cephalon as wide as long; rostral process subequal to the lateral angles. Eyes small, black. Pleonites 1–5 about 1.1 times as long as pereonite 7; pleonites 1–3 with dorsal folds; pleonites 4–5 dorsally fused; pleonite 6 with a median incision at the distal margin. Telson linguiform, medially wider, narrowing distally, rounded apex with numerous marginal setae, proximal region with a pair of statocysts.

ANTENNULE (Fig. 2B). Peduncle with three articles. Articles 1 and 2 with plumose sensory setae; article 2 quadrate, 0.7 times as long as third article, external margin with three long simple setae; flagellum with three articles, subequal to the length of the third peduncular article; tiny distal article with one aesthetasc and a group of simple setae.

ANTENNA (Fig. 2C). Peduncle with five articles. Article 2 rudimentary, subequal in length to articles 2 and 3 together, internal lateral margin with scales; article 4 quadrate, with a group of simple setae at the distal angles; article 5 rectangular, 1.3 times as long as the fourth. Flagellum rudimentary with four articles, 0.6 times as long as last peduncular article.

MAXILLIPED (Fig. 2D). Palp with three articles. Article 1 rectangular with one simple seta; article 2 with one long medial seta and three distal setae, internal margin with setulated scales, bilobed and projected distal angle; article 3 small, oblique with five distal setae. Endite reaching half of the first article of palp.

MAXILLA (Fig. 2E). Straight with seven stout distal teeth.

MANDIBLE (Fig. 2F). Symmetrical; palp with three articles, first article 0.6 times as long as article 2 with a long distal seta; second article 2.5 times as long as article 3 with three distal setae; article 3 with five pectinate setae. Incisor with three teeth; lacinia mobilis with four denticles.

PEREOPOD 1 (Fig. 3A). Subchelate; carpus triangular, apex truncated and crenulated; propodus ovate, 1.8 times as long as wide, palm with middle projection as a step with eight robust short setae; internal distal angle of dactylus projected.

PEREOPODS 2–3 (Fig. 3B–C). Similar in shape and size. Carpus triangular, truncated apically with a small tooth and two long robust setae; propodus elongated oval, 2.1–2.2 times as long as wide, internal margin with a row of simple setae and setulated scales, distoventrally one slightly serrated sensory spine; proximal internal margin of the dactylus with small teeth, distal margin with a robust spine and a group of simple and plumose setae.

PEREOPODS 4–7 (Fig. 3D–G). Very similar in shape and size. Merus with a row of long simple setae and setules on inner margin; carpus subpentagonal, ventrodistal margin with a sensory spine and simple setae, dorsodistal margin with a plumose sensory seta; propodus sub-cylindrical, 1.8 times as long as wide in P4–6, and 2.5 times in P7; ventral margin with simple seta and setulated scales, ventrodistal margin with a denticulate sensory spine. P7 ventrodistally with two pectinate sensory spines; dactylus with setulated scales.

PLEOPOD 1 (Fig. 4A). Protopod with five retinaculae; exopod operculiform, 2.3 times as wide as the endopod, external margin with a medial seta, internal margin with a proximal seta; surrounded laterally and apically by 48 plumose setae; endopod cylindrical, shorter than exopod with six plumose setae on distal margin.

PLEOPOD 2 (Fig. 4B). Oval and elongated, exopod surrounded distally by 14 plumose setae; endopod shorter than exopod, surrounded by eight plumose setae.

UROPODAL PROTOPOD (Fig. 4C). Rectangular, 1.2 times as long as endopod, inner margin with seven plumose setae, outer margin with a row of plumose setae.

UROPODAL ENDOPOD (Fig. 4C). Apex rounded, 1.7 times as long as wide, distally and laterodistally surrounded by long simple setae.

UROPODAL EXOPOD (Fig. 4D). Oval, distally emarginated, 1.6 times as long as wide, surrounded by 67 setae, 21 smooth and 46 plumose.

Distribution and habitat

From Ixtapa, Guerrero to Huatulco, Oaxaca. In algae, coral, coral rock, tubes of sabellariids and molluscan shells; intertidal to subtidal (6 m).

Remarks

Amakusanthura guerrerensis sp. nov. shares the following characteristics with 41 previously recorded species of the genus: (1) maxillipedal palp with three free articles, the internal angle of the second article projected; (2) pleon longer than wide; (3) pleonites 1–3 with dorsal suture lines and 4–5 dorsally fused. The new species differs by presenting a unique combination of characteristics: antenna with scales in the internal margin of the second article; palm of the pereopod 1 with a medial projection as a step armed with eight short setae; exopod of pleopod 1 with one proximal and medial simple seta, and 48 distal plumose setae. Amakusanthura guerrerensis sp. nov. is similar to A. californiensis (Schultz, 1964), the only species recorded in the eastern Pacific, with the following characteristic: (1) more than eight setae in the distolateral part of the telson. The new species, however, differs from A. californiensis in the presence of a pigmented line in the pereonites 3–7 and pleonite 5, distal article of the mandibular palp with five pectinate setae, palm of the pereopod 1 with a medial projection as a step armed with eight short setae and pleonite 6 is strongly emarginated. In comparison, A. californiensis has no pigment, the distal article of the mandibular palp has four setae, palm straight, and the pleonite 6 is slightly emarginated.