Phylogenetic Relationships of the Marine Haplosclerida (Phylum Porifera) Employing Ribosomal (28S rRNA) and Mitochondrial (cox1, nad1) Gene Sequence Data

The systematics of the poriferan Order Haplosclerida (Class Demospongiae) has been under scrutiny for a number of years without resolution. Molecular data suggests that the order needs revision at all taxonomic levels. Here, we provide a comprehensive view of the phylogenetic relationships of the marine Haplosclerida using many species from across the order, and three gene regions. Gene trees generated using 28S rRNA, nad1 and cox1 gene data, under maximum likelihood and Bayesian approaches, are highly congruent and suggest the presence of four clades. Clade A is comprised primarily of species of Haliclona and Callyspongia, and clade B is comprised of H. simulans and H. vansoesti (Family Chalinidae), Amphimedon queenslandica (Family Niphatidae) and Tabulocalyx (Family Phloeodictyidae), Clade C is comprised primarily of members of the Families Petrosiidae and Niphatidae, while Clade D is comprised of Aka species. The polyphletic nature of the suborders, families and genera described in other studies is also found here

<i>Clathria (Cornulotrocha) rosetafiordica</i> sp. nov. from a south-east Pacific fjord (Chilean Patagonia) (Microcionidae: Poecilosclerida: Demospongiae: Porifera)

This article reports on a new species originating from the northern Chilean fjord region, which argued for the resurrection of Cornulotrocha, here classified as a new subgenus of Clathria, for sponges with choanosomal acanthostyles, ectosomal quasidiactinal monactines and rosettes of palmate (an)isochelae. Clathria (Cornulotrocha) rosetafiordica sp. nov. was collected at 23 m depth at Quintupeu fjord (~42°S), and is unique within this very large genus, in possessing rosettes of palmate anisochelae. The new species is compared to the only other known Clathria (Cornulotrocha), viz. C. (Cornulotrocha) cheliradians n. comb.; to the single other Clathria known with anisochelae, viz C. (Thalysias) dubia; to other crustose Clathria from southern South America, the subantarctic and Antarctic areas; and also to other sponges bearing rosettes; and is considered clearly distinct from all. The phylogenetic significance of rosettes is discussed, a likely adaptive value being discarded in view of the variable location of such structures in the distinct poecilosclerid taxa in which they occur