Hestetun Jon Thomassen, Vacelet Jean, Boury-Esnault Nicole, Borchiellini Carole, Kelly Michelle, Ríos Pilar, Cristobo Javier, Rapp Hans Tore
Department of Biology and Centre for Geobiology, University of Bergen, P.O. Box 7803, N-5020 Bergen, Norway.
Aix Marseille Université, CNRS, IRD, Avignon Université, IMBE UMR 7263, 13397 Marseille, France.
Mol Phylogenet Evol. 2016 Jan;94(Pt A):327-45. doi: 10.1016/j.ympev.2015.08.022. Epub 2015 Sep 28.
Carnivorous sponges are characterized by their unique method of capturing mesoplanktonic prey coupled with the complete or partial reduction of the aquiferous system characteristic of the phylum Porifera. Current systematics place the vast majority of carnivorous sponges within Cladorhizidae, with certain species assigned to Guitarridae and Esperiopsidae. Morphological characters have not been able to show whether this classification is evolutionary accurate, and whether carnivory has evolved once or in several lineages. In the present paper we present the first comprehensive molecular phylogeny of the carnivorous sponges, interpret these results in conjunction with morphological characters, and propose a revised classification of the group. Molecular phylogenies were inferred using 18S rDNA and a combined dataset of partial 28S rDNA, COI and ALG11 sequences. The results recovered carnivorous sponges as a clade closely related to the families Mycalidae and Guitarridae, showing family Cladorhizidae to be monophyletic and also including carnivorous species currently placed in other families. The genus Lycopodina is resurrected for species currently placed in the paraphyletic subgenus Asbestopluma (Asbestopluma) featuring forceps spicules and lacking sigmas or sigmancistras. The genera Chondrocladia and Cladorhiza are found to be monophyletic. However, results indicate that the subgenus Chondrocladia is polyphyletic with respect to the subgenera Meliiderma and Symmetrocladia. Euchelipluma, formerly Guitarridae, is retained, but transferred to Cladorhizidae. The four known carnivorous species currently in Esperiopsis are transferred to Abyssocladia. Neocladia is a junior homonym and is here renamed Koltunicladia. Our results provide strong evidence in support of the hypothesis that carnivory in sponges has evolved only once. While spicule characters mostly reflect monophyletic groups at the generic level, differences between genera represent evolution within family Cladorhizidae rather than evolution of carnivory in separate lineages. Conflicting spicule characters can be reinterpreted to support the inclusion of all carnivorous sponges within Cladorhizidae, and a carnivorous habit should thus be considered the main diagnostic character in systematic classification.
肉食海绵的特点是其独特的捕食中层浮游猎物的方式，以及多孔动物门特有的输水系统的完全或部分退化。目前的分类学将绝大多数肉食海绵归入枝根海绵科，某些物种被归入吉他海绵科和埃斯佩里海绵科。形态特征无法表明这种分类在进化上是否准确，以及肉食性是一次进化还是在多个谱系中进化。在本文中，我们展示了首个肉食海绵的全面分子系统发育，结合形态特征解释这些结果，并提出该类群的修订分类。使用18S核糖体DNA以及部分28S核糖体DNA、细胞色素氧化酶亚基I（COI）和海藻糖-6-磷酸合酶11（ALG11）序列的组合数据集推断分子系统发育。结果显示肉食海绵是一个与密骨海绵科和吉他海绵科密切相关的进化枝，表明枝根海绵科是单系的，并且还包括目前置于其他科的肉食性物种。重新启用了Lycopodina属，用于目前置于具有镊子状骨针且缺乏西格马骨针或西格马骨针束的并系亚属石棉海绵（石棉海绵）中的物种。发现软骨枝海绵属和枝根海绵属是单系的。然而，结果表明软骨枝海绵亚属相对于梅利德海绵亚属和对称枝海绵亚属是多系的。以前属于吉他海绵科的真唇海绵属被保留，但被转移到枝根海绵科。目前在埃斯佩里海绵属中的四个已知肉食性物种被转移到深渊枝海绵属。新枝海绵属是一个次同物异名，在此重新命名为科尔图尼枝海绵属。我们的结果提供了有力证据支持海绵的肉食性仅进化了一次这一假说。虽然骨针特征大多反映了属级别的单系类群，但属间差异代表了枝根海绵科内的进化，而非不同谱系中肉食性的进化。相互矛盾的骨针特征可以重新解释，以支持将所有肉食海绵归入枝根海绵科，因此肉食习性应被视为系统分类中的主要诊断特征。
