Green fluorescence is a common phenomenon in marine invertebrates and is caused by green fluorescent proteins. Many hydrozoan species display fluorescence in their polyps and/or medusa stages, and in a few cases patterns of green fluorescence have been demonstrated to differ between closely related species. Hydrozoans are often characterised by the presence of cryptic species, due to the paucity of available morphological diagnostic characters. Zanclea species are not an exception, showing high genetic divergence compared to a uniform morphology. In this work, the morphological and genetic diversity of six coral- and bryozoan-associated Zanclea and one Asyncoryne species from the Maldivian coral reefs were investigated. Specifically, the morphology of polyps and medusae, as well as the cnidome and the interaction with the hosts, were characterised, and the 16S rRNA region was sequenced, compared to deposited sequences, and used to investigate the phylogenetic relationships between the species analysed. Additionally, the presence of green fluorescence in polyps and newly released medusae was explored. Overall, Zanclea species showed a similar morphology, especially the two genetically divergent species associated with scleractinians. Three of the analysed species did not show any fluorescence in both life stages. Other three Zanclea species were distinguished by species-specific fluorescence patterns in the medusae, whereas Asyncoryne ryniensis displayed fluorescence in the polyps. Altogether, the results confirmed the morphological similarity despite high genetic divergence in Zanclea species, and indicated that fluorescence patterns may be good at discriminating closely related cryptic species. Therefore, the assessment of fluorescence at a large scale in the whole Zancleidae family may be useful to shed light on the diversity of this enigmatic taxon.
Предметные области Scopus
- Экология, эволюция поведение и систематика
- Экологическое моделирование
- Природа и охрана ландшафта
- Земледелие и биологические науки (разные)