Dentitheca dendritica ( Nutting 1900 )

Torres-Rodríguez, Javier, Ortiz-Oyola, Daniel, Puentes-Sayo, Alejandra, Lecompte, Orlando P. & Jauregui, Aminta, 2020, Genetic and morphologic identities of hydrozoans (Cnidaria, Hydrozoa) from reef patches of Santa Marta, Colombian Caribbean, Zootaxa 4758 (1), pp. 127-140 : 135-136

2) Dentitheca dendritica ( Nutting 1900) .

D. dendritica is a hydroid reported in the United States on the coast of Florida and on the Caribbean coast of Panama. Plumularia habereri ( Stechow, 1909) a species that inhabits the tropical western Pacific, Indian oceans and the Atlantic has been generally recognized as a different species ( Ryland & Gibbons 1991; Hirohito 1995; Schuchert 2003; Kirkendale & Calder 2003; Di Camilo et al. 2010, Calder 2013). However, Galea (2010) included the record of P. habereri by Flórez (1983) and Bandel & Wedler (1987) from Colombia as synonym of D. dendritica . Here, we do not consider both species as synonyms based on the differences established by Galea (2012) where the gonotheca of D. dendritica originates as replacements of nematotheca adjacent to hydrothecae or on the apophyses, whereas those of P. habereri arise in axils of internode apophyses ( Calder 2013).

The morphological identification up to species level wasn’t possible for the sample Macro1 because of the small amount of tissue available. However, this sequence showed to be related with sequences from Madagascar belonging to Macrorhynchia phoenicea (synonym: Macrorhynchia sibogae (Billard 1913)) , and this suggest the existence of cryptic species from Macrorhynchia genus in the South Caribbean. A more exhaustive sampling is needed in the region in order to obtain more individuals belonging to this genus for a complete analysis.

Due to the lack of studies in the Colombian Caribbean about hydrozoans, the molecular and morphological results found in the present study are of great importance. It is essential to conduct research on this group of organisms that allows expanding the knowledge about their biology, diversity and ecology, mainly in regions where these studies have not been carried out previously. Knowledge on the local biodiversity is an essential pre requisite for the monitoring and management of ecosystems ( Miglietta et al. 2018) and this contribution to the marine hydrozoan fauna in Colombia is an important step to obtain base information for more studies in this taxa.