Systematics of the subfamily Aclyvolvinae (Caenogastropoda: Ovulidae) based on molecular and morphometric analyses

Molecular phylogenetic research on the octocoral-associated gastropod family Ovulidae is still in its infancy and, as a consequence, the relationships between subfamilies and genera are not well defined. Previous research on various ovulid genera has shown that their conchological characters are often too fluid when dealing with species delimitations. For this study, Ovulidae were collected in Indonesia and Malaysia, with some additional specimens obtained from Thailand and the Red Sea. Relationships between the Aclyvolvinae and other ovulid subfamilies were assessed using sequence data from two mitochondrial genes (cytochrome c oxidase subunit I (COI) and 16S rRNA); the dataset contained ovulid species (including type species) from the subfamilies Eocypraeinae, Ovulinae, Pediculariinae and Simniinae. The type species of the subfamilies Eocypraeinae and Sulcocypraeinae are fossils, and hence could not be included in the analyses. The phylogeny and systematics of the subfamily Aclyvolvinae were assessed based on four DNA gene regions (mitochondrial COI and 16S rRNA, and nuclear 28S rRNA and histone H3) and morphometric analyses. Shell morphological characters were analysed to help clarify species delimitations within the Aclyvolvinae. The results from the molecular analyses showed that the subfamilies Aclyvolvinae, Eocypraeinae and Simniinae are polyphyletic, whereas the Ovulinae and Pediculariinae appear to be monophyletic. Within the subfamily Aclyvolvinae, the type species of Hiatavolva, H. depressa, did not form a clade with the other species of Hiatavolva. Instead, H. rugosa and H. coarctata formed a clade that is sister to the clade comprising Aclyvolva lamyi, A. lanceolata and A. nicolamassierae, and are therefore now considered as belonging to the genus Aclyvolva. Aclyvolva lamyi and A. nicolamassierae were shown to be synonyms of A. lanceolata, and A. rugosa (n. comb.) is a synonym of A. coarctata (n. comb.). The genus Kuroshiovolva could not be retrieved in a fixed phylogenetic position within the Aclyvolvinae, nor did it cluster with H. depressa or Aclyvolva spp. Our morphometric analyses are in agreement with the results of the molecular analyses, and furthermore show that juvenile shells are morphologically significantly different from their adult conspecifics. Photographs of the type material of Ovulum lanceolatum, O. coarctatum, Neosimnia lamyi, Hiata rugosa and A. nicolamassierae are provided, and new information is given on the geographical distribution and host species of Aclyvolvinae. The subfamily Aclyvolvinae is redefined and now includes only A. lanceolata and A. coarctata. The genus Hiatavolva is now monotypic, containing only H. depressa, but the subfamily to which this genus belongs remains unclear. Kuroshiovolva is not part of the Aclyvolvinae, but its subfamily level placement is unclear

Scleractinian corals (Fungiidae, Agariciidae and Euphylliidae) of Pulau Layang-Layang, Spratly Islands, with a note on Pavona maldivensis (Gardiner, 1905)

Layang-Layang is a small island part of an oceanic atoll in the Spratly Islands off Sabah, Malaysia. As the reef coral fauna in this part of the South China Sea is poorly known, a survey was carried out in 2013 to study the species composition of the scleractinian coral families Fungiidae, Agariciidae and Euphylliidae. A total of 56 species was recorded. The addition of three previously reported coral species brings the total to 59, consisting of 32 Fungiidae, 22 Agariciidae, and five Euphylliidae. Of these, 32 species are new records for Layang-Layang, which include five rarely reported species, i.e., the fungiids Lithophyllon ranjithi, Podabacia sinai, Sandalolitha boucheti, and the agariciids Leptoseris kalayaanensis and L. troglodyta. The coral fauna of Layang-Layang is poor compared to other areas in Sabah, which may be related to its recovery from a crown-of-thorns seastar outbreak in 2010, and its low habitat diversity, which is dominated by reef slopes consisting of steep outer walls. Based on integrative molecular and morphological analyses, a Pavona variety with small and extremely thin coralla was revealed as P. maldivensis. Since specimens from Sabah previously identified as P. maldivensis were found to belong to P. explanulata, the affinities and distinctions of P. maldivensis and P. explanulata are discussed

Morphology and reproduction in the Hapalocarcinus marsupialis Stimpson, 1859 species complex (Decapoda: Brachyura: Cryptochiridae)

Symbiotic relationships contribute considerably to the high biodiversity found on coral reefs. Coral-dwelling gall crabs (Cryptochiridae) represent a prime example of coral-associated invertebrates that exhibit obligate relationships with their host. The induction of a skeletal modification in the coral, used as a dwelling by the crab, is the most remarkable aspect of this close association. Here we examined Hapalocarcinus marsupialisStimpson, 1859, collected from Pocillopora and Stylophora corals in the Saudi Arabian Red Sea. Specimens were DNA barcoded, and five distinct clades were revealed, providing further evidence for the hypothesis that H. marsupialis is a species complex. Divergence (COI) between the clades ranged from 3.2 to 15.7%. The putative species were tested for differences in morphology and reproduction. Crabs were examined regarding morphometric characters (carapace length and width, pleon (abdomen), chelae, and growth patterns) and reproductive traits. The data were pooled and analysed by host genus and putative species, which revealed significant differences for most of the measured variables in female crabs. Specimens retrieved from Pocillopora were significantly larger (up to 49 %) and had higher fecundity than those inhabiting Stylophora. For reproductive output (RO) no differences at species- or host-genus level were detected. The average RO of ~70% over all specimens is high compared to other brachyurans, supporting the assumption that symbiotic brachyurans invest more energy in reproduction than their free-living counterparts. Discrepancies with published data on growth and reproduction of Hapalocarcinus are discussed. Our results demonstrate the usefulness of morphometric traits and fecundity in separating the clades in the H. marsupialis complex, and prepare the ground for further morphometric studies on the genus and other symbiotic brachyurans. Moreover, it highlights the need to check for the presence of cryptic species when studying aspects of the biology of a species