Fig. 1. Map showing the localities where Acropora corals were sampled during the first Snellius expedition, numbers correspond with Table 1 in The Acropora Humilis Group (Scleractinia) Of The Snellius Expedition (1929-30)

Fig. 1. Map showing the localities where Acropora corals were sampled during the first Snellius expedition, numbers correspond with Table 1.Published as part of <i>van der Meij, Sancia E.T. & Visser, Rémon R., 2011, The Acropora Humilis Group (Scleractinia) Of The Snellius Expedition (1929-30), pp. 9-17 in Raffles Bulletin of Zoology 59 (1)</i> on page 10, DOI: <a href="http://zenodo.org/record/10106670">10.5281/zenodo.10106670</a&gt

Coat of many colours—DNA reveals polymorphism of mantle patterns and colouration in Caribbean Cyphoma Röding, 1798 (Gastropoda, Ovulidae)

The iconic gastropod genus Cyphoma is commonly observed in the Caribbean, where it lives in association with various octocorallian hosts. Each species in the genus Cyphoma has a unique, characteristic mantle pattern and colouration, which separates the valid taxa. Because of its abundance and recognisability Cyphoma gibbosum has been used as a model organism in several studies concerning allelochemicals, reef degradation, and physical defence mechanisms. Molecular analyses based on four molecular markers (COI, 16S, H3 and 28S) for three Cyphoma species (C. gibbosum, C. mcgintyi, C. signatum) and an unidentified black morph, collected from three localities in the Caribbean, show that they represent morphological varieties of a single, genetically homogeneous species. This outcome is in agreement with previous anatomical studies. As a result C. mcgintyi and C. signatum are synonymised with C. gibbosum, which is a key result for future work using C. gibbosum as a model organism. The striking morphological differences in mantle pattern and colouration are hypothesised to be the result of one of three possible scenarios: rapid divergence, supergenes (including balanced polymorphism), or incipient speciation

The stony coral Agaricia tenuifolia Dana, 1848 as a new gall crab host (Decapoda: Cryptochiridae)

<div><p>Abstract Infrequently studied coral species are seldom mentioned as host organisms of associated fauna. Here we report on the stony coralAgaricia tenuifoliaDana, 1848 hosting a gall crab (Cryptochiridae) for the first time. This coral-dwelling crab was observed at the southern coast of Bonaire in the Dutch Caribbean. Based on the shape of the dwelling, and the host specificity of cryptochirids, the crab is tentatively identified asOpecarcinus hypostegus(Shaw & Hopkins, 1977).</p></div

The curious case of <i>Neotroglocarcinus dawydoffi</i> (Decapoda, Cryptochiridae): unforeseen biogeographic patterns resulting from isolation

<div><p>Coral gall crabs form a commonly overlooked component of the associated fauna of shallow-water reef corals and therefore little is known about their ecology and biogeography. This study investigated the biogeography and phylogenetic position of the informal ‘Detocarcini’ species group within the Cryptochiridae. We used molecular data for two mitochondrial markers (COI and 16S) obtained from gall crabs covering (part of) a wide geographic range: the Red Sea, Malaysia, Indonesia and New Caledonia. Our phylogeny reconstructions portrayed the ‘Detocarcini’ as paraphyletic within the monophyletic Cryptochiridae. A phylogeographic clustering was noticed in <i>Neotroglocarcinus dawydoffi</i> that was absent in its sister species, <i>N</i>. <i>hongkongensis</i>, and the closely related species <i>Pseudocryptochirus viridis</i>. A Neighbour Network was estimated for the <i>N</i>. <i>dawydoffi</i> dataset to visualize the similarity between sequences from different biogeographic areas, resulting in three groupings: (1) New Caledonia with Lembeh/Ternate (eastern Indonesia), (2) Semporna/Kudat (eastern Malaysia), and (3) Red Sea (Saudi Arabia). Cryptic speciation rather than isolation is discussed and rejected as an alternative explanation for the observed biogeographic pattern.</p></div

Interspecific coral competition does not affect the symbiosis of gall crabs (Decapoda: Cryptochiridae) and their scleractinian hosts

Coral reefs accommodate a myriad of species, many of which live in association with a host organism. Decapod crustaceans make up a large part of this associated fauna on coral reefs. Among these, cryptochirid crabs are obligately associated with scleractinian corals, in which they create dwellings where they permanently reside. These gall crabs show various levels of host specificity, with the majority of cryptochirids inhabiting a specific coral genus or species. Here, we report the first records of gall crabs living in association with two different Porites species in the Red Sea. Crescent-shaped dwellings were observed in Porites rus and a Porites sp. in situ, and colonies with crabs were collected for further study in the laboratory. Using a combination of morphology and DNA barcoding, the crabs were identified as belonging to Opecarcinus, a genus only known to inhabit Agariciidae corals. The coral skeleton was bleached and studied under a stereo microscope, which revealed that the Porites corals overgrew adjoining agariciid Pavona colonies. We hypothesize that the gall crab originally settled on Pavona, its primary host of choice. Due to coral interspecific competition the Porites colony overgrew the adjacent Pavona colonies, resulting in a secondary and never before reported association of Opecarcinus with Porites. These findings suggest that cryptochirid crabs can adapt to the new microenvironment provided by a different coral host and survive competition for space on coral reefs

沖縄島大渡海岸の潮間帯におけるサンゴヤドリガニ類の記録

沖縄島大渡海岸にて実施した潮間帯調査中に, 高潮帯よりサンゴヤドリガニ類3種が観察されたので記録する. それら3種が寄居した宿種は特異的であり, Opecarcinus cf. sierra Kropp, 1989 はPavona venosa (Ehrenberg, 1834) シコロキクメイシから, Pseudohapalocarcinus ransoni Fize & Serène, 1956ヒメヤドリサンゴガニはPavona divaricata Lamarck, 1816 トガリシコロサンゴから, そしてLithoscaptus sp.はCoelastrea aspera (Verrill, 1866) パリカメノコキクメイシからのみ確認できた. そのうち, パリカメノコキクメイシのある群体では, そのほとんどが水面上に露出し、かつ死んでおり, 表面が藻類に覆われているにも関わらず, 同じく背面に藻類が生えたLithoscaptus sp.が生存しているのが確認された. サンゴヤドリガニ類はサンゴ類が放出するサンゴ粘液に加え, 他の栄養源を利用していることが推測されてきたが, 少なくともこのLithoscaptus sp.の個体はサンゴ粘液にのみ依存していないということが示唆された

A Red Sea Depth Record of the Coral-Dwelling Crab Opecarcinus (Decapoda: Cryptochiridae) in the Mesophotic Zone

Coral-dwelling gall crabs (Cryptochiridae) are obligate symbionts of stony corals and occur on shallow and deep reefs across the tropical belt. The circumtropical genus Opecarcinus associates with Agariciidae corals, a dominant component of Mesophotic Coral Ecosystems (MCEs). Here, we report the first Red Sea mesophotic record, with 89 m as the deepest record to date, for Opecarcinus—collected from Leptoseris cf mycetoseroides—from the NEOM marine area in Saudi Arabia. This observation reconfirms the depth range flexibility of Opecarcinus species and highlights the need for further mesophotic explorations of reef-associated fauna