RESUMO
Tetillidae is a sponge family distributed all over the world but with some genera apparently endemic from the Antarctic and Subantarctic (the "Antarctic clade"). Species identification results tricky due to the similarities of their morphological characters. However, molecular phylogenies have helped to resolve the family taxonomy. The last phylogenetic study on Tetillidae suggested the creation of two new genera: Levantiniella and Antarctotetilla. Lenvantiniella, from Middle East Mediterranean Sea, was previously classified within Cinachyrella, from which it differs in the small rounded surface cavities, distinctive from true porocalices. Antarctotetilla has up to now an Antarctic distribution, and harbors species wrongly classified within Tethya, Craniella, or Tetilla. The main differences of Antarctotetilla to other Tetillidae genera are the presence of pores grouped in small areas, and a poorly-defined cortex (pseudocortex). This study aims to re-describe in detail the species of Tetillidae that belong in the two above mentioned new genera, and to highlight that molecular phylogenies should be combined with morphological analyses to improve taxonomical decisions. We also describe a new Tetillidae species with a hair-like hispidation, which we name Antarctotetilla pilosa nov. sp. Furthermore, the types of Tethya coactifera and T. crassispicula (Lendenfeld, 1907) were reexamined because of some morphological similarities with Antarctotetilla. The minibarcode sequences (a small COI fragment) placed them within the Antarctic clade harboring Antarctotetilla and Cinachyra, but did not resolve their genus position. A morphological revision, however, suggests placing T. coactifera in Antarctotetilla, while T. crassispicula, which owns porocalices and a spicule-reinforced cortex, appeared to belong in Cinachyra.
Assuntos
Filogenia , Poríferos , Animais , Regiões Antárticas , Mar Mediterrâneo , Oriente MédioRESUMO
[This corrects the article DOI: 10.1371/journal.pone.0160718.].
RESUMO
Species of Tetillidae are distributed worldwide. However, some genera are unresolved and only a few genera and species of this family have been described from the Antarctic. The incorporation of 25 new COI and 18S sequences of Antarctic Tetillidae to those used recently for assessing the genera phylogeny, has allowed us to improve the resolution of some poorly resolved nodes and to confirm the monophyly of previously identified clades. Classical genera such as Craniella recovered their traditional diagnosis by moving the Antarctic Tetilla from Craniella, where they were placed in the previous family phylogeny, to Antarctotetilla gen. nov. The morphological re-examination of specimens used in the previous phylogeny and their comparison to the type material revealed misidentifications. The proposed monotypic new genus Levantiniella had uncertain phylogenetic relationships depending on the gene partition used [corrected]. Two more clades would require the inclusion of additional species to be formally established as new genera. The parsimony tree based on morphological characters and the secondary structure of the 18S (V4 region) almost completely matched the COI M1-M6 and the COI+18S concatenated phylogenies. Morphological synapomorphies have been identified for the genera proposed. New 15 28S (D3-D5) and 11 COI I3-M11 partitions were exclusively sequenced for the Antarctic species subset. Remarkably, species within the Antarctic genera Cinachyra (C. barbata and C. antarctica) and Antarctotetilla (A. leptoderma, A. grandis, and A. sagitta), which are clearly distinguishable morphologically, were not genetically differentiated with any of the markers assayed. Thus, as it has been reported for other Antarctic sponges, both the mitochondrial and nuclear partitions used did not differentiate species that were well characterized morphologically. Antarctic Tetillidae offers a rare example of genetically cryptic (with the traditional markers used for sponges), morphologically distinct species.
RESUMO
Temperate reefs, built by multilayers of encrusting algae accumulated during hundreds to thousands of years, represent one of the most important habitats of the Mediterranean Sea. These bioconstructions are known as "coralligenous" and their spatial complexity allows the formation of heterogeneous microhabitats offering opportunities for a large number of small cryptic species hardly ever considered. Although sponges are the dominant animal taxon in the coralligenous rims with both insinuating and perforating species, this group is until now poorly known. Aim of this work is to develop a reference baseline about the taxonomic knowledge of sponges and, considering their high level of phenotypic plasticity, evaluate the importance of coralligenous accretions as a pocket for biodiversity conservation. Collecting samples in four sites along the coast of the Ligurian Sea, we recorded 133 sponge taxa (115 of them identified at species level and 18 at genus level). One species, Eurypon gracilis is new for science; three species, Paratimea oxeata, Clathria (Microciona) haplotoxa and Eurypon denisae are new records for the Italian sponge fauna, eleven species are new findings for the Ligurian Sea. Moreover, seventeen species have not been recorded before from the coralligenous community. The obtained data, together with an extensive review of the existing literature, increase to 273 the number of sponge species associated with the coralligenous concretions and confirm that this habitat is an extraordinary reservoir of biodiversity still largely unexplored, not only taxonomically, but also as to peculiar adaptations and life histories.
