Phylogenetic systematics and zoogeography of australian nudibranchs description of a new species of thecacera with comments on the genus and its contained species

Thecacera boyla n.sp is described from coastal northern Queensland. Its most striking character is the elaboration of the rhinophoral sheaths into long, mobile “tentacles” that serve as sensory appendages, apparently in lieu of velar papillae. The genus Thecacera is holophyletic and probably derived from Polycera - like polycerids. Because four (possibly five) of the six valid biological species are tropical, it is probable Thecacera is tropically centered. There appears to be a gradient of decreasing species diversity eastwards from southeastern Africa

A review of diets in the notaspidea (Mollusca: Opisthobranchia)

This paper reviews the scattered and often anecdotal literature on foods for the opisthobranch order Notaspidea. All Umbraculacea are sponge-feeders (accepting sponges of the class Demospongiae only). The Pleurabranchacea shows a diversity of diet: Berihella species eat sponges (Demospongiae); Berthellina species eat sponges (Demospongiae;? Calcarea) and cnidarians (Scleractinia — not previously reported;? Actiniaria); Pleurobranchus species eat ascidians; Pleurobranchaea (and apparently Pleurobranchella) species are opportunistic carnivores that accept a range of soft-bodied invertebrates (Cnidaria; Annelida; Mollusca). It appears that cnidarians (Actiniaria; Hydroida) are amongst the more preferred items in the diet of Pleurobranchaea species. The review is supplemented with observations on feeding of Berthellina citrina (RUppell & Leuckart) and Pleurobranchaea maculata (Quoy & Gaimard) made at Leigh, New Zealand

Description of the aeolid nudibranch favorinus tsuruganus baba and abe, 1964 from eastern australia

Favorinus tsuruganus Baba and Abe, 1964 (Opisthobranchia: Nudibranchia) is redescribed from material taken in Queensland and New South Wales waters. Characters of its external anatomy, alimentary and reproductive systems (e.g., structures of propodial tentacles, ceratal arrangement, jaws, penis), as well as the behaviour of living animals agree well with those known not only for Japanese specimens but also for Favorinus species in general. The radular teeth are unusual, but not exceptional, in having smooth sides to the cusp. Coloration and shape of the rhinophores are the most distinctive features

Description of a new aeolid nudibranch (Mollusca: Opisthobranchia) belonging to the genus phidiana

The nudibranch Phidiana pegasus n. sp. is described and illustrated. It possesses, besides distinctive coloration, autapomorphies related to rhinophoral ornamentation and cerata. P. pegasus is endemic to the Three Kings Islands where it apparently replaces the New Zealand mainland P. milleri Rudman. The nudibranch fauna of the Three Kings Islands is shown to be low as regards species diversity

The taxonomy of two host-specific, cryptic dendronotoid nudibranch species (Mollusca: Gastropoda) from Australia including a new species description

Two host-specific, extremely cryptic, small dendronotoid nudibranchs from Australia are described and classified, and their phylogenetic position within the superfamily is discussed. Lomanotus vermiformis Eliot 1908 subsists exclusively on the hydrozoan Lytocarpus philippinus (Kirchenpauer, 1872). Lomanotus stauberi Clark & Goetzfried 1976 is newly synonymized with L. vermiformis. Marioniopsis platycteneasp. nov. subsists exclusively on the alcyonacean Parerythropodium hicksoni Utinomi 1972. Marianina rosea (Pruvot-Fol 1930) is relocated to the Tritoniidae (wherein it forms a monotypic subfamily, Marianinae) because of possession of palmate rhinophoral clavi, the principal apomorphy of the Tritoniidae. The validity of using the form of the digestive gland as a basis for dividing the Tritoniidae is questioned since it is acknowledged that this organ has progressed from a solid (holohepatic) arrangement to a dispersed (cladohepatic) arrangement in parallel in several major nudibranch lineages; form thus offers merely homoeoplaseous phylogenetic characters. Separation of right and left digestive glands appears to be one of the first steps in the simultaneous and interdependent evolutionary processes of internal detorsion and external 'aeolidization' in nudibranchs

Ultrastructure and phylogenetic significance of notaspidean spermatozoa (mollusca, gastropoda, opisthobranchia)

Spermatozoa of five notaspidean opisthobranchs [Berthellina citrina, Berthella ornata, Pleurobranchus peroni, Pleurobranchaea maculata, Umbraculum sinicum] were examined using TEM. In all five species, the acrosome (sensu lato) consists of an apical vesicle (the acrosomal vesicle) and acrosomal pedestal. The acrosomal pedestal overlaps the nuclear apex, and in P. peroni (and possibly B. ornata) is periodically banded-the first reported incidence of this type of substructure in any euthyneuran acrosome. Although sperm nuclei of P. peroni, B. ornata and B. citrina differ in length and also the number of keels present (nucleus 7 μm long with four/five keels present in Pleurobranchus; 17 μm long with one keel in Berthella; 15 μm long with a very weak keel in Berthellina), the basal invagination to which the centriolar derivative, axoneme and coarse fibres are attached is always poorly developed, and very little overlap between nucleus and midpiece occurs. In P. maculata and U. sinicum, the nucleus forms a helical cord around the axoneme and mitochondrial derivative such that it is not possible to recognize exclusively 'nuclear' and 'midpiece' regions of the spermatozoon. In all notaspideans investigated, (1) the axoneme, coarse fibres and glycogen helix are enclosed by the paracrystalline and matrix components of the mitochondrial derivative and (2) a dense ring structure (attached to the plasma membrane) and glycogen piece are observed. While the glycogen piece is very short (0.85-1.43 μm) with a very degenerate axoneme in B. citrina, B. ornata and P. peroni, this region of the spermatozoan is well developed (30-35 μm long) in U. sinicum and exhibits a fully intact 9 + 2 axoneme. The 'glycogen piece' (or its presumed homologue) in P. maculata spermatozoa is very short (0.65 μm), devoid of any axonemal remnant and constructed of a hollow, internal cylinder attached to an outer (incomplete) shell, and contains scattered (? glycogen) granules. Spermatozoal structure supports a close relationship between the genera Berthellina, Berthella and Pleurobranchus. These three genera have more distant links with Pleurobranchaea, while Umbraculum maintains an isolated. specialized position within the Notaspidea

Checklist of the nudibranchs (Opisthobranchia: Nudibranchia) of the South China Sea

Raffles Bulletin of Zoology488 SUPPL.513-53