Amakusanthura lucinae, Jarquín-Martínez & Gálvez-Zeferino & Morales-Zárate & Salinas-Zavala, 2023

Jarquín-Martínez, Ubaldo, Gálvez-Zeferino, Neysi, Morales-Zárate, María Verónica & Salinas-Zavala, César Augusto, 2023, Four new species of anthuroids (Peracarida: Isopoda) from the temperate-tropical transition zone of the western coast of Baja California Peninsula, Mexico, Zootaxa 5360 (1), pp. 91-112 : 93-98

publication ID	https://doi.org/ 10.11646/zootaxa.5360.1.5
publication LSID	lsid:zoobank.org:pub:0A0697C3-4480-49E0-B7D2-32478F1EDDB9
DOI	https://doi.org/10.5281/zenodo.10164814
persistent identifier	https://treatment.plazi.org/id/03FD386C-5C11-9B5A-99D6-FA97FF126217
treatment provided by	Plazi
scientific name	Amakusanthura lucinae
status	sp. nov.

Treatment

Amakusanthura lucinae sp. nov.

Figs 2–4 View FIGURE 2 View FIGURE 3 View FIGURE 4

Material examined. Holotype: CIB-0055_ISO 2, non-ovigerous female, 8 mm, Guerrero Negro Lagoon , Baja California Peninsula, Mexico, station 5, in fine sand, 8.2 m, Nov 7, 2012, coll. M. V. Morales-Zárate.

Paratypes: CIB-0056_ISO 3, 2 non-ovigerous females, same sampling station as holotype.

Additional material: CIB-0057_ISO 4, 3 non-ovigerous females, station 10, in fine sand, 8.7 m, Dic 4, 2012, coll. M. V. Morales-Zárate.

Diagnosis: Body 12 times longer than wide; pleon subequal at the pereonite 7 lengths. Antennula with three aesthetascs. Article 3 of mandibular palp with two robust setae. Pereopod 1 palm projected step-like and seven marginal setae. Pleopod 1 exopod with 45 distal setae. Pleotelson 2.1 times longer than wide, proximally concave, medially convex, rounded posterior part with 10 dorsal setae, emarginate apex with four seta pairs.

Holotype description (non-ovigerous female CIB-0055_ISO 2): Body length 8 mm ( Fig. 2A, B View FIGURE 2 ), 12 times longer than wide; head rectangular, 1.2 times longer than wide; rostrum shorter than anterolateral lobes. Pereonites 1 and 2 cylindrical; pereonites 3–7 rectangular; pereonite 7 shorter than the rest, 0.8 times pereonite 6 lengths; pleonite 1.2 times longer than wide; subequal at the length of pereonite 7. Pleonites 4 and 5 partially fused. Uropodal endopod larger than pleotelson. Pleotelson 2.1 times longer than wide, proximally concave, medially convex, superior part rounded with 10 dorsal setae, apex emarginated with four seta pairs.

Antennula ( Fig. 2C View FIGURE 2 ) with three peduncular articles and three flagellar articles. Peduncular article 1 rectangular, with one distal plumose seta; article 2 oblong, 0.4 times longer than article 1 length, with two distal simple setae and three short plumose; article 3, 1.1 times longer than the second one, with a large ventrodistal seta; flagellum about as long as peduncular article 3, distal article with three aesthetascs.

Antenna ( Fig. 2D View FIGURE 2 ) with five peduncular and four flagellar articles. Peduncular article 1 0.3 times longer than the second one; article 2 0.3 times longer than peduncle, with a simple distal seta; article 3 0.4 times longer than article 2, with a simple distal seta; article 4 subequal to article 3, with four distal setae; article 5 with six distal setae. Flagellum shorter than peduncular article 5, minute distal article with numerous setae.

Mandible ( Fig. 2E View FIGURE 2 ) palp with three articles. Palp article 1 with one distal long seta; article 2 1.3 times longer than article 1, with two simple distal setae; article 3 with two pectinated setae and a lateral row of fine setae. Incisor with four cusps, lamina dentata with four teeth.

Maxilla ( Fig. 2F View FIGURE 2 ) dorsodistally folded, with seven distal teeth.

Maxilliped ( Fig. 2G View FIGURE 2 ) with tri-articulate palp. Palp article 1 rectangular, with one internal distal seta; article 2 is the largest, with three simple lateral and three distal setae; article 3 oblique, with six lateral setae. Endite slightly shorter than article 1, with numerous short setae.

Pereopod 1 ( Fig. 3A, B View FIGURE 3 ) subchelate, robust. Ischium thinner than basis, with one dorsal and one ventrodistal simple seta. Merus shorter than the ischium and broader than long, with one ventrodistal and two dorsoproximal setae. Carpus triangular, produced ventrodistally, margin rugose, with two ventral setae and four subdistal setae. Propodus broad, with two ventroproximal, two ventromedial, and two ventrodistal simple setae. Palm stepped, margin with four proximal and five distal setae. Dactylus with ventrodistal short spine seta and six distal setae, internal margin with a cuticular crest, and a simple seta.

Pereopods 2–3 ( Fig. 3C, D View FIGURE 3 ) similar in shape. Basis elongated, oval with sensorial setae. Ischium slightly shorter than the basis, with two dorsodistal, 1–2 ventrodistal, and one ventromedial seta. Merus narrow proximally, internal margin rugose with five ventral and three dorsodistal simple setae. Carpus triangular, with one robust distal and 4–5 simple setae. Propodus ovate; with ventrodistal short spine seta and three simple setae, ventral margin with 4–5 simple setae.

Pereopods 4–7 ( Fig. 3E–F View FIGURE 3 , 4A–B View FIGURE 4 ) basis with 1–2 plumose sensorial and one simple setae. Ischium with one dorsal and four ventral setae. Merus rugose, with 6–8 ventral and 3–4 dorsodistal setae. Carpus sub-pentagonal, with one distal short spine seta and 4–5 ventral simple setae. Propodus elongated oval, with two ventral and two ventrodistal short setae, ventrodistal angle with one short spine seta, ventrodistal angle of the pereopods 6 and 7 with one or two pectinid robust setae. Dactylus with ventral setulated scales.

Pleopod 1 ( Fig. 4C View FIGURE 4 ) exopod 2.4 times longer than wide, distal margin with 45 plumose setae. Endopod 0.3 times the width of the exopod; distal margin with six plumose setae.

Pleopod 2 ( Fig. 4D View FIGURE 4 ) exopod 3.3 times longer than wide, with 11 distal setae. Endopod 0.7 times the length of the exopod, distal margin with eight plumose setae.

Uropod ( Fig. 4E, F View FIGURE 4 ) rectangular protopod, 1.6 times longer than wider, 1.2 times the length of the endopod, with five ventral short simple and one long plumose seta; dorsal margin with approximately 10 plumose setae. Endopod 1.7 times longer than wide, rounded external margin with numerous long simple setae. Exopod 2.1 times longer than wider, distal region strongly emarginated, margin surrounded by approximately 71 plumose and simple setae.

Etymology: The specific name of this species refers to the memory of Lucina Zeferino, the beloved mother of the second author.

Habitat: In soft bottom, fine sand.

Geographical distribution: Coastal lagoon of the temperate-tropical climatic transition zone of the Mexican Pacific, western coast of the Baja California Peninsula: Guerrero Negro Lagoon, Baja California, Mexico .

Remarks: Amakusanthura Nunomura, 1977 includes 44 species ( Boyko et al. 2023), of which two have been recorded in the Eastern Pacific: A. californiensis ( Schultz, 1964) in California and A. guerrerensis Jarquín-Martínez & García-Madrigal, 2021 in the tropical part of Mexico. Amakusanthura lucinae sp. nov. is more similar to A. californiensis by showing a non-pigmented body, uropodal endopod longer than the pleotelson, and rounded pleotelson, apically emarginated with a group of setae. However, the new species differs from A. californiensis and other species of Amakusanthura in (1) number of setae in the mandibular palp distal article; (2) form and ornamentation of the palm of pereopod l; (3) endopod and uropodal exopod proportions; and (4) number of dorsal pleotelson setae.

Amakusanthura lucinae sp. nov. has two robust setae in the distal article of the mandibular palp; the palm projection is short and step-like with a series of seven ventral setae; the uropodal endopod is 1.7 times longer than wide, exopod 2.1 times longer than wide, and the pleotelson has 10 dorsal setae. Whereas A. californiensis has five robust setae in the distal article of the mandibular palp; pereopod 1 palm is straight with numerous setae; endopod and the uropodal exopods are narrower than in Amakusanthura lucinae sp. nov., and dorsal part of the pleotelson smooth.