title: Morphological and molecular analyses of a new species of Saccocoelioides Szidat, 1954 (Haploporidae Nicoll, 1914) in the fat sleeper Dormitator maculatus (Bloch) (Perciformes: Eleotridae) from the Gulf of Mexico.
abstract: Saccocoelioides olmecae n. sp. is described from specimens recovered from the intestine of the fat sleeper Dormitator maculatus (Bloch) (Perciformes: Eleotridae) collected in six localities along the coast of the Gulf of Mexico. The new species is mainly distinguished from the other three described species of Saccocoelioides Szidat, 1954 from North and Middle America (i.e. S. sogandaresi Lumsden, 1963, S. chauhani Lamothe-Argumedo, 1974 and S. lamothei Aguirre-Macedo & Violante-González, 2008) by having an elongated body, a sac-like caecum, a uterus that extends to the first third of body and by having vitelline follicles longitudinally elongated reaching the posterior end of the body. Sequences of the large subunit (LSU) of the ribosomal DNA, including the domain D1-D3, and the internal transcribed spacer 2 (ITS2) were used independently and concatenated to corroborate the morphological distinction among S. olmecae n. sp., S. chauhani and S. lamothei from freshwater and brackish-water fish from Middle America. The genetic divergence estimated among the three species of Saccocoelioides was very low: 1% for LSU and from 1 to 4% for ITS2. Maximum likelihood and Bayesian inference analyses for each dataset and both datasets combined revealed that S. olmecae n. sp. represents an independent clade with moderate bootstrap support and posterior probabilities. This is the third species of Saccocoelioides described in Mexico, and the 17th species from the Americas.
authors.affiliation: Posgrado en Ciencias Biológicas,Instituto de Biología,Universidad Nacional Autónoma de México,A. P. 70-153,C.P. 04510,Ciudad de México.
authors.forename: L
authors.initials: L
authors.lastname: Andrade-Gómez
authors.affiliation: Posgrado en Ciencias Biológicas,Instituto de Biología,Universidad Nacional Autónoma de México,A. P. 70-153,C.P. 04510,Ciudad de México.
authors.forename: C D
authors.initials: CD
authors.lastname: Pinacho-Pinacho
authors.affiliation: Instituto de Biología Marina y Pesquera Almirante Storni,Universidad Nacional del Comahue,Güemes 1030,8520 San Antonio Oeste,Río Negro,Argentina.
authors.forename: J S
authors.initials: JS
authors.lastname: Hernández-Orts
authors.affiliation: Departamento de Zoología,Instituto de Biología,Universidad Nacional Autónoma de México,A. P. 70-153,C.P. 04510,Ciudad de México.
authors.forename: A L
authors.initials: AL
authors.lastname: Sereno-Uribe
authors.affiliation: Departamento de Zoología,Instituto de Biología,Universidad Nacional Autónoma de México,A. P. 70-153,C.P. 04510,Ciudad de México.
authors.forename: M
authors.initials: M
authors.lastname: García-Varela
mesh_terms: D000818:Animals; D016000:Cluster Analysis; D018509:DNA, Helminth / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D005393:Fish Diseases / Q000469:parasitology*; D060851:Gulf of America; D007422:Intestines / Q000469:parasitology; D008853:Microscopy; D010473:Perciformes; D010802:Phylogeny; D012335:RNA, Ribosomal / Q000235:genetics; D017422:Sequence Analysis, DNA; D014200:Trematoda / Q000033:anatomy & histology / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D018509:DNA, Helminth; D004275:DNA, Ribosomal; D021903:DNA, Ribosomal Spacer; D012335:RNA, Ribosomal; C065096:RNA, ribosomal, 26S