title: Morphology and molecules on opposite sides of the diversity gradient: four cryptic species of the Cliona celata (Porifera, Demospongiae) complex in South America revealed by mitochondrial and nuclear markers.
abstract: A great number of marine organisms lack proper morphologic characters for identification and species description. This could promote a wide distributional pattern for a species morphotype, potentially generating many morphologically similar albeit evolutionarily independent worldwide lineages. This work aimed to estimate the genetic variation of South America populations of the Cliona celata species complex. We used COI mtDNA and ITS rDNA as molecular markers and tylostyle length and width as morphological characters to try to distinguish among species. Four distinct clades were found within the South American C. celata complex using both genetic markers. The genetic distances comparisons revealed that scores among those clades were comparable to distances between each clade and series of previously described clionaid species, some of which belong to different genera. Our results also suggest that one of the clades has a broad discontinuous distribution in the Atlantic Ocean, while another presents high gene flow between the southern Atlantic and Pacific coasts of South America. Conversely, spicule morphology was not able to distinguish each clade, due to the high degree of overlap among them. Therefore, we considered that each recovered clade correspond, in fact, to different species that cannot be differentiated via morphological characters, which are often used to describe species within the C. celata species complex.
authors: Departamento de Genética, Universidade do Estado do Rio de Janeiro, Rua São Francisco Xavier, 524, PHLC 201, Maracanã, CEP 20550-013, Rio de Janeiro, RJ, Brazil.
authors: Thiago Silva
authors: TS
authors: de Paula
authors: Carla
authors: C
authors: Zilberberg
authors: Eduardo
authors: E
authors: Hajdu
authors: Gisele
authors: G
authors: Lôbo-Hajdu
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D050259:Genes, Mitochondrial; D005819:Genetic Markers; D014644:Genetic Variation; D007494:Ireland; D016013:Likelihood Functions; D008390:Markov Chains; D008957:Models, Genetic; D009010:Monte Carlo Method; D010802:Phylogeny; D058974:Phylogeography; D011161:Porifera / Q000033:anatomy & histology* / Q000145:classification / Q000235:genetics*; D012339:RNA, Ribosomal, 28S / Q000235:genetics*; D012044:Regression Analysis; D017422:Sequence Analysis, DNA; D013020:South America
chemical_list: D021903:DNA, Ribosomal Spacer; D005819:Genetic Markers; D012339:RNA, Ribosomal, 28S