Population-level morphological variation of Anisotremus interruptus (Gill, 1862) (Perciformes: Haemulidae) in the Tropical Eastern Pacific, with the description of two new species Author Acevedo-Álvarez, Edgar Adrián Programa Institucional de Maestría en Ciencias Biológicas, Facultad de Biología. Universidad Michoacana de San Nicolás de Hidalgo. Michoacán. México. Author Ruiz-Campos, Gorgonio Colección Ictiológica, Facultad de Ciencias, Universidad Autónoma de Baja California, Carretera Transpeninsular 3917, Fracc. Playitas 22860, Ensenada, Baja California, México Author Domínguez-Domínguez, Omar Laboratorio de Biología Acuática, Facultad de Biología. Universidad Michoacana de San Nicolás de Hidalgo. Michoacán. México. Instituto Nacional de Biodiversidad, Pje. Rumipamba N. 341, Quito, Ecuador. text Zootaxa 2021 2021-05-24 4975 1 141 158 journal article 6191 10.11646/zootaxa.4975.1.5 06cd2741-40b2-4eb7-9e13-d032fcc2d8e6 1175-5326 4805536 B772FA12-2E05-43A7-B555-E497E83B51C6 Anisotremus espinozai Acevedo-Álvarez, Ruiz-Campos & Domínguez-Domínguez , sp. n. ( Figure 7b ) urn:lsid:zoobank.org:pub: D88F9151-97B5-44F0-AA96-E0CDDE40521F Type material: Holotype . MECN-DP 4358 , tissue number-46746, 28.37 cm LE . Cerro Gallina , Isla Santa Cruz , Galapagos Archipelago , Ecuador . Geographic coordinates: Latitude 00°43´40.2”N , longitude 90°39´54.32”W . 13 February 2017 . Col. Rolando Quetzalcoatl Torres-García , Juan Carlos Quevedo-Machado , and Paola Nallely Palmerín-Serrano. Paratypes : CPUM-13493, same data as holotype, 13 specimens . CPUM-13494, Islote Espejo, Isla Marchena, Galapagos Archipelago , Ecuador . Geographic coordinates: Latitude 00°18´46.18”N , longitude 90°24´4.64”W . Col. Dahiana Arcila, Adrián Jaramillo-López, Rosa Gabriela Beltrán-López, 3 specimens . CPUM-13496, Poza Lobos, Isla Marchena, Galapagos Archipelago , Ecuador . Geographic coordinates: Latitude 00°19´6.29”N , longitude 90°28´38.34”W . Col. Dahiana Arcila, Adrián Jaramillo-López, Rosa Gabriela Beltrán-López , 1 specimen . CPUM-13495, Bahía Darwin , Isla Genovesa , Galapagos Archipelago , Ecuador . Geographic coordinates: Latitude 00°18´58.38”N , longitude 89°57´15.71”W . Col.Yareli López-Arroyo , Omar Domínguez-Domínguez , Francisco Martínez-Servín , Carmen del Rocío Pedraza-Marrón , Eduardo Espinoza , Emanuell Duarte-Ribeiro , 4 specimens . CNPE-IBUNAM23792, Bahía Darwin , Isla Genovesa, Galapagos Archipelago , Ecuador . Geographic coordinates: Latitude 00°18´58.38”N , longitude 89°57´15.71”W . Col. Yareli López-Arroyo , Omar Domínguez-Domínguez, Francisco Martínez-Servín, Carmen del Rocío Pedraza-Marrón , Eduardo Espinoza, Emanuell Duarte-Ribeiro , 3 specimens . CPUM-6073, Punta Pitt , Isla San Cristóbal , Galapagos Archipelago , Ecuador . Geographic coordinates: Latitude 00°42´44.08”N , longitude 89°14´51.91”W . Col. Salvador Romero-Gallardo, Eloísa Torres-Hernández, Oscar Lasso-Alcalá, Julio César Orantes-Ávalos, 1 Specimen . CPUM-14115, Frente a Ulloa , Isla del Coco , Costa Rica . Geographic coordinates: Latitude 5°33´5.04”N , longitude 87°2´11.77”W . Col. Yareli López-Arroyo and Francisco Martínez-Servín , 1 specimen . CPUM-14116, Manuelita Profundo , Isla del Coco , Costa Rica . Geographic coordinates: Latitude 5°33´40.08”N longitude 87°2´54.29”W , Col. Yareli López-Arroyo , Francisco Martínez-Servín , 1 specimen . Diagnosis. Anisotremus espinozai differs from the rest of the species complex of A. interruptus from Pacific Ocean, as well as its sister species A. surinamensis from the Atlantic Ocean by the combination of the following meristic characters (expressed by their mode followed in parentheses by their range): 8 (7-9) scales from the origin of the dorsal fin to the lateral line vs 7 (6-8) in A. interruptus and 7 (7-9) in A. surinamensis ; 27 (23-28) scales around the caudal peduncle vs 22 (21-25) in A. interruptus and 24 (22-27) in A. perezponcedeleoni ; 21 (19-24) caudal peduncle upper scales vs 17 (15-20) in A. interruptus ; 20 (18-24) scales between the upper origin of the opercula vs 17 (15-20) in A. interruptus and 19 (18-20) in A. surinamensis ; 10 (9-12) scales from the origin of the dorsal fin at the beginning of the head vs 9 (9-10) in A. interruptus ; 27 (24-29) scales from the origin of the anal fin to the origin of the dorsal fin vs 23 (21-25) in A. interruptus and 26 (24-28) in A. surinamensis ; and 27 (21-26) scales from the origin of the dorsal rays to the anal fin vs 22 (20-23) in A. interruptus , 22 (20-25) in A. surinamensis and 25 (22-26) in A. perezponcedeleoni ( Table 2 ). FIGURE 7 . a) Anisotremus perezponcedeleoni sp. n. , Holotype CPUM-9858, Las Pirámides, Isla Clarión, Archipelago de Revillagigedo, Manzanillo, Colima, México. b) Anisotremus espinozai sp. n. , Holotype MECN-DP 4358, Cerro Gallina, Isla Santa Cruz, Archipiélago de las Galápagos, Ecuador. c) Anisotremus interruptus , CPUM-9924, Playa La Privada, San Juan de Alima, Michoacán, México. Each morphometric characters of A. espinozai is presented as a ratio to the SL (expressed by the average value followed in parentheses by the range): Distance from the anterior insertion of the dorsal fin to the anterior insertion of the ventral fin 2.27 (2.22-2.40) vs 2.32 (2.19-2.48) in A. perezponcedeleoni and 2.20 (2.0-2.34) in A. interruptus ; distance from the origin of the anal fin to the origin of the dorsal fin 1.75 (1.68-1.88) vs 1.64 (1.54-1.71) in A. interruptus ; dorsal fin length 1.75 (1.61-1.84) vs 1.72 (1.64-1.80) in A. perezponcedeleoni and 1.65 (1.56-1.70) in A. interruptus ; distance from the anterior insertion of the anal fin to the insertion of the pelvic fin 3.18 (2.91-3.62) vs 3.06 (2.85-3.31) in A. perezponcedeleoni and 2.92 (2.77-3.21) in A. interruptus ; distance from the snout to the origin of the anal fin 1.39 (1.32-1.44) vs 1.38 (1.33-1.44) in A. perezponcedeleoni and 1.35 (1.30-1.39) in A. interruptus ; predorsal distance 2.19 (2.07-2.35) vs 2.30 (2.24-2.53) in A. perezponcedeleoni and 2.23 (2.04-2.36) in A. interruptus and length from the origin to the end of the dorsal rays 4.37 (4.08-4.92) vs . 4.22 (4.01-4.65) in A. perezponcedeleoni and 3.92 (3.72-4.24) in A. interruptus . The dorsal fin of A. espinozai is supported by 26 pterygiophores inserted in 17 neural spines, starting in vertebrate two vs 26 pterygiophores inserted in 18 neural spines in A. perezponcedeleoni and 28 pterygiophores inserted in 18 neural spines in A. interruptus ; the anal fin is supported by 11 pterygiophores inserted in 8 hemal spines vs 11 pterygiophores inserted in 9 hemal spines in A. perezponcedeleoni . Description. Anisotremus espinozai has 16 to 18 (mode= 17) dorsal rays, 9 to 10 (mode= 10) anal rays, 17 to 19 (mode=18) pectoral rays, and 17 to 19 (mode= 18) caudal rays; number of scales ranges from 7 to 9 (mode= 8) from the dorsal fin origin to the lateral line; 51 to 56 (mode= 54) scales on the lateral line; 23 to 28 (mode= 27) scales around the caudal peduncle; 18 to 24 (mode= 20) scales between the upper origin of the opercula; 10 to 13 (mode= 10) scales between pectoral and pelvic fins; 24 to 29 (mode= 27) scales from the origin of the dorsal fin to the origin of the anal fin; 9 to 12 (mode= 10) predorsal scales; 19 to 24 (mode= 21) caudal peduncle upper scales; 21 to 26 (mode= 24) scales from the origin of the dorsal rays to the anal fin. The body is high and laterally compressed, its maximum depth is 2.74 times within the SL and its minimum depth is 8.42 times in the SL. The head is high and robust, with a slightly pronounced nape, its length is 3.41 times in the SL. Eye diameter 2.95 times in the head length. Lips are thick and fleshy. Serrated pre-operculum. Long pectoral fin tip reaching the origin of the anal fin. Forked caudal fin. Body covered with slightly large scales throughout the body and head except for chin, front of snout and lips ( Table 2 ). Twenty-five vertebrae (10 precaudal plus 15 caudal), the caudal region supporting 19 branched rays with two upper and one lower hypural plates, two upper epural plates and one lower parhypural plate. Pigmentation. The body is uniformly silver. The center of the scales and the caudal peduncle are dark. Pectoral, caudal, dorsal, ventral and anal fins show yellowish coloration. Sexual dimorphism . No evident sexual dimorphism. Etymology. The name of the species, an adjective, is derived from the name of the conservationist and resource manager M.Sc. Eduardo Espinoza, Galapagos National Park Marine Reserve, Ecuador , who strongly contributed to the conservation and knowledge of Galapagos Archipelago fish diversity. Distribution and habitat: Endemic to the Galapagos Archipelago and Cocos Island. Collections were made at depths ranging from 4 to 8 m . All individuals were found associated with rocky reefs. Some individuals were observed in underwater caves. Conservation. Individuals of this new species are common in the study locations, forming small and large schoals. This species is not caught commercially in the area. The Galapagos Archipelago and Cocos Island are National Parks and both are under strict protection and management. As such, the species currently appears to be protected.