taxonID	type	description	language	source
03FD386C5C119B5A99D6FA97FF126217.taxon	description	Figs 2 – 4	en	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): 91-112, DOI: 10.11646/zootaxa.5360.1.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5360.1.5/52107
03FD386C5C119B5A99D6FA97FF126217.taxon	materials_examined	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.	en	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): 91-112, DOI: 10.11646/zootaxa.5360.1.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5360.1.5/52107
03FD386C5C119B5A99D6FA97FF126217.taxon	diagnosis	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.	en	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): 91-112, DOI: 10.11646/zootaxa.5360.1.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5360.1.5/52107
03FD386C5C119B5A99D6FA97FF126217.taxon	materials_examined	Holotype description (non-ovigerous female CIB- 0055 _ ISO 2): Body length 8 mm (Fig. 2 A, B), 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. 2 C) 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. 2 D) 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. 2 E) 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. 2 F) dorsodistally folded, with seven distal teeth. Maxilliped (Fig. 2 G) 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. 3 A, B) 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. 3 C, D) 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. 3 E – F, 4 A – B) 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. 4 C) 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. 4 D) 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. 4 E, F) 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.	en	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): 91-112, DOI: 10.11646/zootaxa.5360.1.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5360.1.5/52107
03FD386C5C119B5A99D6FA97FF126217.taxon	etymology	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.	en	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): 91-112, DOI: 10.11646/zootaxa.5360.1.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5360.1.5/52107
03FD386C5C119B5A99D6FA97FF126217.taxon	discussion	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.	en	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): 91-112, DOI: 10.11646/zootaxa.5360.1.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5360.1.5/52107
03FD386C5C149B5699D6FE37FC9566EF.taxon	description	Figs 5 – 7	en	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): 91-112, DOI: 10.11646/zootaxa.5360.1.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5360.1.5/52107
03FD386C5C149B5699D6FE37FC9566EF.taxon	materials_examined	Material examined. Holotype: CIB- 0058 _ ISO 5, adult female, 9.8 mm, Guerrero Negro Lagoon, Baja California Peninsula (station 9, in fine sand, 5.0 m), Nov 14, 2017, coll. M. V. Morales-Zárate. Paratype: CIB- 0059 _ ISO 6, 1 adult female, same sampling station as the holotype. Additional material: CIB- 0060 _ ISO 7, 1 adult female, station 7, fine sand, 11.6 m, Jan 17,2018, coll. M. V. Morales-Zárate; CIB- 0061 _ ISO 8, 1 adult female, station 9, fine sand, 5.0 m, Jan 17, 2018, coll. M. V. Morales-Zárate; CIB- 0062 _ ISO 9, 1 adult female, station 9, fine sand, 5.0 m, Jan 17, 2018, col. M. V. Morales-Zárate.	en	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): 91-112, DOI: 10.11646/zootaxa.5360.1.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5360.1.5/52107
03FD386C5C149B5699D6FE37FC9566EF.taxon	diagnosis	Diagnosis: Body 13.6 times longer than wide; pleon 1.2 times longer than wide and slightly larger than pereonite 7. Antennula with three aesthetascs. Article 1 of mandibular palp with one proximal seta, article 2 with 10 setae. Palm of pereopod 1 slightly medially projected with a row of 20 robust setae. Exopod of pleopod. 1 strongly emarginated, with approximately 40 distal setae. Pleotelson distally narrow, truncated apex with eight subapical and six apical setae.	en	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): 91-112, DOI: 10.11646/zootaxa.5360.1.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5360.1.5/52107
03FD386C5C149B5699D6FE37FC9566EF.taxon	materials_examined	Holotype description (adult female CIB- 0058 _ ISO 5): Body length (Figs. 5 A, B) 9.8 mm, 13.6 times longer than wide. Cephalon 1.1 times longer than wide and 0.5 the length of the pereonite 1; eyes absent. Pereonite 1 and 2 cylindrical, pereonites 3 – 6 rectangular, pereonite 7 square, 0.6 times the length of pereonite 6. Pleon 1.2 times longer than wide and slightly longer than pereonite 7, pleonites fused. Pleotelson distally narrow, truncated apex with eight subapical and six apical setae. Antennula (Fig. 5 C) with three peduncular and three flagellar articles. Peduncular article 1 as long as articles 2 and 3, with three dorsal plumose sensorial and 10 simple setae; article 2 0.5 times the length of article 1, with nine dorsal smooth and one dorsal plumose sensorial seta; article 3 0.8 times the length of the second one, with five ventral and five distal setae. Flagellum approximately 0.7 times the length of the peduncular article 3; distal article with three aesthetascs. Antenna (Fig. 5 D) with five peduncular articles and four flagellar articles. Peduncular article 1 0.3 times the length of article 2; article 2 the largest, 0.7 times length of distal articles; article 3 rectangular, 0.4 times length of article 2, with two distal short setae; article 4 sub-square, 0.8 times length of article 3, with four distal setae; article 5 cylindrical, with one dorsodistal sensorial and four simple setae. Flagellum almost half the length of peduncular article 5; distal article with numerous fine setae. Mandible (Fig. 5 E) palp with two articles. Article 1 0.5 times length of the 2, with a slender proximal and one long distal seta; article 2 with 10 long setae. Incisor with four cusps, lamina dentata with approximately 12 denticles, molar acute. Maxilla (Fig. 5 F) dorsodistally folded, with seven distal teeth. Maxilliped (Fig. 5 G) with tri-articulate palp. Palp article 1 rectangular, 0.6 times length of second, with a long distal seta; article 2 with three medial and two apical setae; article 3 the smallest, oblique, internal margin with four thick setae. Pereopod 1 (Fig. 6 A, B) subchelate, robust. Ischium thinner than the basis. Carpus triangular, rounded apically with a group of nine medial setae. Propodus broad, with 19 ventral setae. Palm slightly medially projected with one row of 20 robust setae. Dactylus with ventrodistal short spine seta and four distal short setae. Unguis longer than dactylus. Pereopods 2 – 3 (Fig. 6 C, D) with numerous long setae. Basis cylindrical, with dorsal plumose sensorial setae and one long simple seta. Ischium distally narrow, with six dorsal setae, internal margin rugose with a row of simple setae. Merus with numerous ventral long setae. Carpus triangular, with two robust apical setae and numerous thin setae. Propodus oval elongated, 1.8 times longer than wide in P 2 and 1.5 times longer than wide in P 3; internal margin with 3 – 4 short, one long setae, and ventrodistal short spine seta. Pereopods 4 – 7 (Fig. 6 E – F; 7 A – B) with numerous long setae. Basis with plumose sensorial and one long simple seta. Ischium with numerous setae in the internal margin. Merus distally narrow, rugose internal margin, with numerous long setae. Carpus pentagonal, with one distal short spine seta and along simple setae; external margin with one plumose seta. Propodus of pereopod 7 cylindrical, 3.5 times longer than wide, internal margin with setulated scales and two pectinated spines. Pleopod 1 (Fig. 7 C) operculiform exopod, 2.6 times longer than wide, with a strong distolateral emargination, distal margin with approximately 40 plumose setae. Endopod cylindrical, 0.5 times the width of the exopod, with seven distal setae. Pleopod 2 (Fig. 7 D) exopod 2.7 times longer than wide, slightly emarginated in the distal region, narrow apex, rounded, with 19 plumose setae. Endopod slightly longer than the exopod with 10 distal setae. Uropod (Fig. 7 E, F) rectangular protopod, 2 times longer than basal width, with a ventrodistal plumose seta. Endopod lanceolated, 1.5 times the length of the protopod, with a group of smooth setae in the distal region and a row of five setae in the external margin. Exopod auriculiform, 2.6 times longer than wide, external margin with numerous short plumose setae accompanied with smooth setae; dorsal surface covered with short setae.	en	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): 91-112, DOI: 10.11646/zootaxa.5360.1.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5360.1.5/52107
03FD386C5C149B5699D6FE37FC9566EF.taxon	etymology	Etymology: This species is named in memory and honoring Dr. Daniel Lluch-Belda, a Mexican scientist who dedicated part of his scientific legacy to the study of marine climate transition zones in northwestern Mexico. Habitat: In soft bottom, fine sand. Geographic 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.	en	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): 91-112, DOI: 10.11646/zootaxa.5360.1.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5360.1.5/52107
03FD386C5C149B5699D6FE37FC9566EF.taxon	discussion	Remarks: Besides the new species, three species of the genus Cortezura: C. penascoensis Schultz, 1977; C. confixa (Kensley, 1978); and C. caeca Jarquín-Martínez & García-Madrigal, 2021 have been described. Among these species, C. lluchbeldai sp. nov. is the most similar to C. penascoensis in the shape of the mandible and pereopod 1. However, they differ in that the new species shows 19 setae in the palm (vs. 10 setae in C. penascoensis), antennula with numerous long setae (vs. setae present only in article 3). C. lluchbeldai sp. nov. also differs from C. caeca in the number of palm setae (13 short setae in C. caeca) and the first mandibular palp article shows a proximal seta (vs. absent in C. caeca). Likewise, it distinguishes from C. confixa in the telson shape and palm projection, in C. lluchbeldai sp. nov. distally narrow and the palm slightly projected (vs. rounded and with a denticle strongly projected, respectively in C. confixa). Cortezura lluchbeldai sp. nov. is distinguished from all other species by the following characteristics: (1) maxillipedal palp with three articles; (2) exopod of the pleopod 1 with a strong emargination in the distolateral region; and (3) distal article of the mandibular palp with 10 setae.	en	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): 91-112, DOI: 10.11646/zootaxa.5360.1.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5360.1.5/52107
03FD386C5C189B4D99D6F9FEFD22638B.taxon	description	Figs 8 – 10	en	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): 91-112, DOI: 10.11646/zootaxa.5360.1.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5360.1.5/52107
03FD386C5C189B4D99D6F9FEFD22638B.taxon	materials_examined	Material examined. Holotype: CIB- 0063 _ ISO 10, adult female, 8.7 mm, Guerrero Negro Lagoon, Baja California Peninsula (station 4, in fine sand, 8.0 mm), Sep 12, 2017, coll. M. V. Morales-Zárate. Paratype: CIB- 0064 _ ISO 11, 9 adult females, same sampling station as holotype. Additional material: CIB- 0065 _ ISO 12, 5 adult females, station 10, in fine sand, 8.2 m, Dec 14, 2012, coll. M. V. Morales-Zárate; CIB- 0066 _ ISO 13, 3 adult females, station 5, in fine sand, 8.2 m, Nov 7, 2012, coll. Morales-Zárate; CIB- 0067 _ ISO 14, 1 adult female, station 8, in fine sand, 2.5 m, Nov 6, 2012, coll. M. V. Morales-Zárate; CIB- 0068 _ ISO 15, 8 adult females, station 5, in fine sand, 8.2 m, Dec 4, 2012, coll. M. V. Morales-Zárate.	en	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): 91-112, DOI: 10.11646/zootaxa.5360.1.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5360.1.5/52107
03FD386C5C189B4D99D6F9FEFD22638B.taxon	diagnosis	Diagnosis: Body 11.5 times longer than wide; pigment of pereonites 1 – 6 in circular shape; pigment of pereonite 7 rectangular. Article 3 of the mandibular palp with seven robust setae; projected molar process. Pereopod 1 palm projected medially, with one row of eight short setae. Pleopod 1 exopod operculiform, 1.8 times longer than wider, with 38 distal setae, endopod with nine distal setae. Pleotelson rounded with 10 apical setae.	en	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): 91-112, DOI: 10.11646/zootaxa.5360.1.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5360.1.5/52107
03FD386C5C189B4D99D6F9FEFD22638B.taxon	materials_examined	Holotype description (adult female CIB- 0063 _ ISO 10): Body length 8.7 mm (Fig. 8 A), 11.5 times longer than wide; pigment of pereonites 1 – 6 in circular shape; pigment of pereonite 7 rectangular. Cephalon 1.1 times larger than wider, 0.7 times the length of pereonite 1. Pereonite 7 square, 0.7 times the length of pereonite 6. Pleon 1.1 times longer than wide and 1.2 times longer than pereonite 7; pleonites 1 – 5 completely fused. Pleotelson linguiform, rounded apex with 10 setae. Antennula (Fig. 8 B) with three peduncular and three flagellar articles. Article peduncular 1 1.7 times larger than wider, external margin with five plumose sensorial setae; article 2 subsquare, 0.5 times the length of the article 1, with three medial and three ventrodistal sensorial setae; article 3 cylindrical, 1.4 times larger than the article 2, with 4 distal simple setae. Flagellar article 1 with one plumose sensorial seta; article 3 with three aesthetascs and five simple setae. Antenna (Fig. 8 C) with five peduncular and five flagellar articles. Peduncular article 1 with one short seta; article 2 1.3 times longer than wide, with two distal setae; article 3 partially embedded in article 2, with two ventrodistal setae; article 4 subsquare, with a long and two short distal setae; article 5 cylindrical, 1.3 times larger than article 4, internal margin with a row of short setae. Flagellum much shorter than the last peduncular article; distal article minute, with numerous fine setae. Mandible (Fig. 8 D) palp with three articles. Article 1 elongated, cylindrical, 0.6 times the length of the second article, with a distal seta; article 2 cylindrical, with one short medial and one long distal seta; article 3 0.4 times the length of the article 2, with seven robust setae. Incisor with three cusps; lamina dentata with five denticles, projected molar process. Maxilla (Fig. 8 E) with eight distal teeth, dorsodistal margin with fine setae. Maxilliped (Fig. 8 F) palp with three articles. Article 1 rectangular, 0.6 times the length of the article 2, internal margin with two short and one long setae; article 2 with one short proximal seta; article 3 oblique, internal margin with three plumose setae, one proximal and two distal; medial margin with two long smooth and three short setae. Pereopod 1 (Fig. 9 A, B) subchelate. Basis more robust distally. Ischium thinner than the basis. Carpus triangular, rugose apical margin, with one mediodistal and four distal short setae. Propodus oval, palm projected medially with a row of eight marginal short setae, distal part with two long setae. Pereopods 2 – 3 (Fig. 9 C, D) similar in shape and setation. Basis oval-elongated, with dorsal plumose sensorial setae. Merus with 1 – 2 ventral and one dorsodistal seta. Carpus triangular, with four distal setae. Propodus cylindrical, 2.7 times longer than wide in P 2 and 2.3 times longer than wide in P 3, internal margin with one short spine seta and 4 – 5 simple setae. Pereopods 4 – 7 (Fig. 9 E – G, 10 A) similar in shape and setation. Carpus pentagonal, with one ventrodistal short spine seta and 3 – 4 simple setae. Propodus cylindrical, with two ventromedial short setae, one ventrodistal short spine seta, and one long simple seta; internal margin of the propodus and dactylus of pereopod 7 with setulated scales. Pleopod 1 (Fig. 10 B) exopod operculiform, 1.8 longer than wide, distal margin with 39 plumose setae. Endopod cylindrical, as long as the exopod, 0.3 times the width of the exopod, with nine distal plumose setae. Pleopod 2 (Fig. 10 C) exopod 3.1 longer than wider, with 10 plumose setae. Endopod with eight distal setae. Uropod (Fig. 10 D, E) rectangular protopod, 2 times longer than wide and 1.7 times longer than the endopod; external margin with numerous plumose setae. Endopod sub-circular, 1.1 times longer than wider, margin with numerous smooth setae and some of them plumose. Exopod auriculiform, almost 2 times longer than wider, distal region emarginated, crenulated margin with numerous plumose setae accompanied with smooth ones.	en	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): 91-112, DOI: 10.11646/zootaxa.5360.1.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5360.1.5/52107
03FD386C5C189B4D99D6F9FEFD22638B.taxon	etymology	Etymology: This species receives the nickname “ Coco ” in honor of Dr. María del Socorro García-Madrigal aka Coco, a Mexican scientist who has dedicated her scientific legacy to the study of marine crustaceans in Mexico. Habitat: In soft bottom, fine sand. Geographic 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.	en	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): 91-112, DOI: 10.11646/zootaxa.5360.1.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5360.1.5/52107
03FD386C5C189B4D99D6F9FEFD22638B.taxon	discussion	Remarks. Mesanthura cocoae sp. nov. differs from the previously recorded Mesanthura species by the following diagnostic characteristics: Pigmentation pattern; distal article of the mandibular palp with seven setae; molar process projected; pereopods 2 – 7 with scarce setae. M. cocoae sp. nov. is similar to M. occidentalis Menzies & Barnard, 1959 by showing the following characteristics: (1) palm of pereopod 1 medially projected; (2) propodus of pereopods 2 – 7 with ventral setulated scales; and (3) antennular flagellum with three aesthetascs. However, M. cocoae sp. nov. differs in the pigmentation pattern of pereonites 1 – 6, which is subcircular reticulated and rectangular in pereonite 7; the apical region of the pleotelson has six pairs of setae; setation of the antennae is scarce; article 3 of mandibular palp has seven setae, and the uropodal endopod is circular and 1.1 times longer than wide. In M. occidentalis the pigmentation of pereonites 1 – 6 is circular and distributed on the segment periphery, in pereonite 7 the pigment is a distal line; pleotelson apical region has eight pairs of setae; antennae show numerous short setae in the articles; article 3 of the mandibular palp with five setae; uropodal endopod is oval and as long as wide. This brings to six the number of species of Mesanthura from Mexico, the others being M. antenniformis Jarquín-Martínez & García-Madrigal, 2021, M. estacahuitensis Jarquín-Martínez & García-Madrigal, 2021, M. nubifera Wägele, 1984, and Mesanthura sp. Brusca, 1980.	en	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): 91-112, DOI: 10.11646/zootaxa.5360.1.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5360.1.5/52107
03FD386C5C039B4999D6FE12FCAD6217.taxon	description	Figs 11 – 13	en	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): 91-112, DOI: 10.11646/zootaxa.5360.1.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5360.1.5/52107
03FD386C5C039B4999D6FE12FCAD6217.taxon	materials_examined	Material examined. Holotype: CIB- 0069 _ ISO 16, adult female, 8.7 mm, Guerrero Negro Lagoon, Baja California Peninsula (station 4, in fine sand, 8.0 m), Sep 12, 2017, coll. M. V. Morales-Zárate. Additional material: CIB- 0070 _ ISO 17, 15 adult females, station 5, in fine sand, 8.2 m, Nov 7, 2012, coll. M. V. Morales-Zárate; CIB- 0071 _ ISO 18, 17 adult females, 6 ovigerous females, station 8, in fine sand, 2.5 m, Nov 6, 2012, coll. M. V. Morales-Zárate; CIB- 0071 _ ISO 19, 1 adult female, station 10, in fine sand, 8.2 m, Sep 6, 2012, coll. M. V. Morales-Zárate.	en	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): 91-112, DOI: 10.11646/zootaxa.5360.1.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5360.1.5/52107
03FD386C5C039B4999D6FE12FCAD6217.taxon	diagnosis	Diagnosis: Body 9.6 longer than wide; pleon as large as wide, subequal at the length of the pereonite 6 and 7. Pereopod 1 oval propodus, 1.5 times longer than wide, with a group of nine mesial robust setae; propodus of pereopods 2 and 3 with six spine setae; pereopods 4 – 6 with two medial spine setae. Exopod of pleopod 1 two times longer than wider, with 16 distal setae. Sub-circular uropodal endopod, 1.2 times longer than wider; uropodal exopod 1.7 times longer than wider. Pleotelson 2.2 times longer than wider.	en	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): 91-112, DOI: 10.11646/zootaxa.5360.1.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5360.1.5/52107
03FD386C5C039B4999D6FE12FCAD6217.taxon	materials_examined	Holotype description (adult female CIB- 0069 _ ISO 16): Body length 5 mm (Fig. 11 A, B), 9.6 times longer than wider; color brown; cephalon 1.1 times longer than wider and 0.8 times the length of the pereonite 1. Pleon as long as wide, subequal at the length of the pereonites 6 and 7. Pleotelson 2.4 times larger than wider. Antennula (Fig. 11 C) with three peduncular and three flagellar articles. Peduncular articles 1 and 2 with plumose sensorial setae; article 1 1.4 times longer than article 2; article 3 rectangular, as long as article 2. Flagellum 0.8 times the length of the last peduncular article, article 3 with three aesthetascs. Antenna (Fig. 11 D) with five peduncular and three flagellar articles. Peduncular article 2 long, 0.6 times the length of articles 3 and 4 jointly, article 3 longer than wider; article 4 distally narrow with one long simple seta and two plumose sensorial setae; article 5 cylindrical, 1.4 times longer than article 4. Flagellum much shorter than the last peduncular article, with numerous setae. Mandible (Fig. 11 E) reduced, conical, palp absent. Maxilla (Fig. 11 F) styliform, with 11 distal denticles. Maxilliped (Fig. 11 G) with two articles; article 1 long, with two distomedial short and four long setae; article 2 minute, with a group of four setae. Pereopod 1 (12 A) subchelate. Basis cylindrical, 2.1 times longer than wider. Ischium as long as the basis. Merus shorter than the ischium, with one ventrodistal and two dorsoproximal setae. Carpus triangular, with four distal setae. Propodus oval, 1.5 times longer than wider, with a group of nine mesial robust setae, palm with eight marginal and three ventral short setae. Pereopod 2 – 3 (Fig. 12 B, C) similar in shape. Basis with sensorial setae. Merus distally narrow, with one ventrodistal and two dorsodistal setae. Carpus triangular, with three distal setae. Propodus of P 2 1.7 times longer than wider, palm with five spine setae; propodus of P 3 1.8 times longer than wider, palm with six spine setae. Pereopod 4 – 6 (Fig. 12 D – F) basis with plumose sensorial setae. Merus distally narrow, with two ventrodistal and two dorsodistal setae. Carpus with two ventral spine setae, 2 – 3 ventrodistal, and two dorsodistal setae. Propodus 1.8 times longer than wider in P 4 and 3.1 in P 5 and P 6, internal margin with setulated scales, two medial and one distal spine setae. Pleopod 1 (Fig. 13 A) exopod operculiform, 2 times longer than wider, distal margin with 16 plumose setae. Endopod approximately 0.2 times the width of the exopod, distal margin with 11 plumose setae. Pleopod 2 (Fig. 13 B) exopod 2.4 times longer than wider, with eight distal plumose setae. Endopod shorter than the exopod, 0.7 times wider than the exopod, with four distal plumose setae. Uropod (Fig. 13 C, D) rectangular protopod, distally 1.6 longer than wider. Endopod sub-circular, 1.2 times longer than wider, slightly shorter than the protopod; margin with simple and some sensory setae. Exopod filiform, 1.7 times longer than wider, with approximately 23 plumose setae accompanied by smooth setae. Etymology: This species is named after the coastal Guerrero Negro Lagoon off the western coast of the Baja California Peninsula where the type material was collected. Habitat: In soft bottom, fine sand. Geographic 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: Colanthura guerreronegroensis sp. nov. is similar to C. bruscai Poore, 1984 by the shape of the antennae and number of aesthetascs, pleon subequal to pereonite 6 + 7, as long as wide, and the setae pattern in the palm of the pereopods 1 – 3. However, differs because in C. guerreronegroensis sp. nov. the propodus of pereopod 1 is 1.5 times longer than wide and 1.7 – 1.8 in the pereopod 2 – 3; sixth segment of the pleotelson is a strongly distal lobule, and the telson is 2.1 times longer than wider; while C. bruscai the pereopod 1 propodus is 1.3 times longer than wider and 1.5 times longer than wider in pereopod 2; the lobules of the sixth segment of the pleotelson are short and straight, and the pleotelson is 1.3 times longer than wider.	en	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): 91-112, DOI: 10.11646/zootaxa.5360.1.5, URL: https://www.mapress.com/zt/article/download/zootaxa.5360.1.5/52107
