The systematics and phylogeny of Phyllidiid Nudibranchs (Doridoidea)

Abstract

ABSTRACT. Investigations into the taxonomy, phylogeny, biogeography and ecology of nudibranchs belonging to the family Phyllidiidae Rafinesque are reported. All prior research on thc Phyllidiidae is reviewed. There were 74 nominal species as of January, 1992. The literature revealed enormous confusion in the taxonomy of phyllidiids caused primarily from inadequate anatomical study (or none at all) and descriptions of single preserved specimens. Intraspecific variation, particularly its ontogenetic component, is identified as an additional cause of misidentification.Traditional sources of nudibranch taxonomic characters, such as jaws and radula, are lacking in the Phyllidiidae. Characters used in this study are: general shape and body profile; colour and pattern; morphology of notal tubercles, ridges, and the mantle margin; rhinophoral colour; number of lamellae on each rhinophoral clavus; gills; morphology of foot and foot sole; oral tentacles; anatomy of the alimentary system; anatomy of the reproductive system; penial spine morphology; and sperm ultrastructure.Six genera are recognised and each is redescribed. Features which clearly demarcate the genera occur principally in the digestive system, and also in the reproductive system and external morphology. A key to genera is provided. A total of 49 valid, Indo-Pacific species is recognised; a full synonymy is given for each species. Phyllidia Cuvier remains the largest genus with 15 (including 8 new) species. Fryeria Gray is considered a valid genus with six (including 3 new) species. Phyllidiella Bergh is reinstated and nine (including 4 new) species are recognised. Phyllidiop.sis Bergh, the second largest genus, contains 14 (including 6 new) species. Ceratc~phyllidia Eliot appears to contain three (including 2 new) species, however specimens are very rarely collected and further work remains to be done prior to their formal description. The recently described genus Reticulidia Brunckhorst contains two species. In all, 22 new species of phyllidiid nudibranchs are described.Study of anatomy has allowed a phylogenetic hypothesis to be proposed for the first time. Cerutophyllidiu is the sister group to the remaining genera. Phyllidia, Fryeria and Reticulidia are the most derived genera. The morphology and anatomy of phyllidiids indicates monophyly with dorids. However, the grouping of the Phyllidiidae and Dendrodorididae as Porostomata is Record5 of the Austral~an Museum (1993) Supplement 16 polyphyletic and rejected as homeoplaseous . Differences in foregut anatomy between the two groups support the view that suctorial feeding of sponges has arisen independently in both groups .Biogeographical distribution of species and ecological observations are reported . As a result of field observations. the sponge foods of several phyllidiid species are reported for the first time .The sponge food and chemical defence compounds of phyllidiid species may also be useful in taxonomic study . In situ observations of feeding and study of the functional anatomy of the forcgut e...

Addition to the opisthobranchiate (Opisthobranchia, Mollusca) fauna of Andaman and Nicobar Islands, India

“…Animals were observed, photographed in the field and samples were collected for identification. Live specimens brought to the laboratory Identification was carried out based on morphological characters and available literatures (Brunckhorst 1993;Gosliner 1995;Gosliner et al 2008; http://www.seaslug forum.net/; http://www.nudipixel.net). Status was described as Abundant＝more than 30 observations; Common＝5 to 30 observations; and Rare＝less than 5 observations.…”

Comparison and cost benefit analysis of different data sets used for determining mollusc evolution: a case study of the cryptobranch nudibranch Halgerda (Mollusca: Gastropoda)

“…The exceptions to this are the studies by Brunckhorst (1993) and Valdes and Gosliner (1999). In these two publications, the absence or presence of chemicals, used presumably for defense, is used as a taxonomic character or characters.…”

“…However, both Healy and Willan (1991) and Wagele and Willan (2000) acknowledged sperm morphology as a very valuable character. Healy and Willan (1991) Natural product chemistry as a taxonomic indicator Natural products have infrequently been used as taxonomic tools to characterize marine mollusc groups (Brunckhorst 1993;. Indeed, most researchers to date, with some significant exceptions Cimino and Ghiselin 1999;Cimino and Ghiselin 2001), utilize the biochemistry of opisthobranchs not as an evolutionary tool, but as a method by which to determine the origin of various compounds within the mollusc, e.g.…”

Marine benthic invertebrates use multimodal cues for defense against reef fish

“…The dorid nudibranch family Phyllidiidae contains over 49 species of nudibranchs distributed throughout the Indo-Pacific (Brunckhorst 1993). Most phyllidiid nudibranchs have contrasting color patterns, and many species (although most remain untested) sequester isocyanide terpenes and related compounds from their host sponges (Chang & Scheuer 1993, Dumdei et al 1997.…”