No abstract

Correct identification and classification of sponges is challenging due to ambiguous or misleading morphological features. A particular case is a blue keratose sponge occasionally referred to as the “Blue Photo Sponge” among aquarists, which appears frequently (and in several cases unintended) in private aquaria. This spicule-less species, occasionally specified as Collospongia auris Bergquist, Cambie & Kernan 1990, not only displays a high phenotypic plasticity in growth form and colour, it also proliferates in aquacultures under standard conditions unlike most other sponges. Therefore, this species is regarded as a pest for most aquarists. In turn, the ease of cultivation and propagation in aquacultures qualifies this species as a model organism for a wide array of scientific applications. For these purposes, correct identification and classification are indispensable. We reconstructed ribosomal gene trees and determined this species as Lendenfeldia chondrodes (De Laubenfels, 1954) (Phyllospongiinae), distant to Collospongia auris, and corroborated by skeletal features. Additionally, the resulting phylogeny corroborated major shortcomings of the current Phyllospongiinae classification—its consequences are discussed.

Keratose (horny) sponges constitute a very difficult group of Porifera in terms of taxonomy due to their paucity of diagnostic morphological features. (Most) keratose sponges possess no mineral skeletal elements, but an arrangement of organic (spongin) fibers, with little taxonomic or phylogenetic information. Molecular phylogenetics have targeted this evolutionary and biochemically important lineage numerous times, but the conservative nature of popular markers combined with ambiguous identification of the sponge material has so far prevented any robust phylogeny. In the following study, we provide a phylogenetic hypothesis of the keratose order Dictyoceratida based on nuclear markers of higher resolution potential (ITS and 28S C-region), and particularly aim for the inclusion of type specimens as reference material. Our results are compared with previously published data of CO1, 18S, and 28S (D3-D5) data, and indicate the paraphyly of the largest dictyoceratid family, the Thorectidae, due to a sister group relationship of its subfamily Phyllospongiinae with Family Spongiidae. Irciniidae can be recovered as monophyletic. Results on genus level and implications on phylogenetic signals of the most frequently described morphological characters are discussed.

This paper is the fifth in a series revising the taxonomy of New Zealand dictyoceratid sponges (phylum Porifera, subclass Ceractinomorpha, order Dictyoceratida). Six new species of the genus Spongia are added to New Zealand's known fauna. The use of subgenera within the genus Spongia is discussed, and two new subgenera are proposed. The genus Hippospongia is revised, and an emended generic diagnosis is proposed.

The status of species within the dictyoceratid sponge genus Psammocinia is reviewed. The separation of Psammocinia species from the closely related Ircinia species, which has been the subject of some dispute, is clarified. This distinction made on the basis of morphological evidence is supported by the limited chemotaxonomic and molecular phylogenetic data available. Six new species of Psammocinia are described from the New Zealand region.