Research Article |
Corresponding author: Alexandra Hiller ( alexandrahiller40@gmail.com ) Academic editor: Ingo S. Wehrtmann
© 2018 Alexandra Hiller, Bernd Werding.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Hiller A, Werding B (2018) On a new commensal species of Aliaporcellana from the western Pacific (Crustacea, Decapoda, Porcellanidae). ZooKeys 780: 1-9. https://doi.org/10.3897/zookeys.780.26388
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Aliaporcellana spongicola sp. n. from the Philippines and Indonesia is described. The new species has been frequently photographed by divers because of its striking coloration, but has not been described yet. Aliaporcellana spongicola sp. n. is in fact a widespread commensal of barrel sponges of the genus Xestospongia and other sponges. Morphological characters and ecological information of all described species of Aliaporcellana, and of other porcellanids associated with sponges and soft corals, suggest that all members of the genus are commensals, and that similar morphological adaptations to dwelling on these hosts have evolved independently in different evolutionary lines within Porcellanidae.
Crustacea , Porcellanidae , Aliaporcellana , new species, Indo-West Pacific, commensalism, adaptation, sponge- and octocoral-dwelling
The porcellanid genus Aliaporcellana was established by
Here we describe a new sponge-dwelling species of Aliaporcellana from material collected in the Philippines and Indonesia. Despite having been frequently photographed by divers because of its striking coloration and relatively large size, the species has not been described. With the exception of A. telestophila , commensalism has never been reported for other congeners. We highlight the characters distinguishing the new species from its congeners, and discuss the morphological traits, present in all Aliaporcellana species and other porcellanids associated with sponges, which we interpret as adaptations to living on these hosts.
We found the new species in material collected in the Philippines by G. Paulay [Florida Museum of Natural History, Gainesville, U.S.A. (
Holotype: female (ovigerous), NMCR 4966, ex
Carapace rounded (Figures
Eyes moderately large (Figures
Third thoracic sternite (Figure
Chelae moderately different in size and form (Figures
Walking legs (Figures
Details of Aliaporcellana spongicola sp. n., female (ovigerous) paratype,
Coloration. The background color of carapace and extremities is bright orange (hexadecimal color #e86700), overlain with a reticulate bright blue (hexadecimal color #000de8) pattern (Figures
Aliaporcellana currently consists of six species. Of all species, A. spongicola sp. n. is by far the most strikingly colorful, and has, therefore, become popular among underwater photographers and marine aquarists. Aliaporcellana spongicola sp. n. dwells on large barrel sponges of the genus Xestospongia Laubenfels [family Petrosiidae; e.g., X. testudinaria (Lamarck 1815)] and on other types of sponges, like the “large, grey foliose sponge”, on which the crabs from Sulawesi included in this study, were found. The porcellanid lies in the sponge’s folds, where it is most protected from predators (Figure
The type specimens come from the central Philippines and northern Sulawesi, Indonesia.
The name spongicola (from the Latin word spongia, meaning sponge, and the Latin suffix cola, meaning dwelling) refers to the sponge-dwelling habit of the new species.
Aliaporcellana spongicola sp. n. is considerably variable in the shape of carapace and the degree of spination on body and extremities. As in other porcellanid species, the spines are more defined in smaller specimens. The new species is distinguished from A. pygmaea and A. kikuchii by the lack of acute spines on the dactylus of the smaller cheliped (
With the description of Aliaporcellana spongicola sp. n., the genus now comprises six species.
Up to now, A. telestophila is the only species of the genus reported to live as commensal (
Our own observations of the morphology and ecology of A. suluensis collected from sponges in Saudi Arabia, and of all other Aliaporcellana species, led us to conclude that perhaps all species of the genus are commensals. We base our conclusions on the well-developed, fixed spines on the dactylus of the walking legs, a character present in all Aliaporcellana species (see Figures
The association between crab and sponge may be easily overlooked because sponges are often attached to each other and to rocks, and are damaged when the rocks are lifted. More collection data of other Aliaporcellana species are needed to confirm the commensal status of the genus.
We are grateful to G. Paulay, A. Bemis, and J. Slapcinsky (Florida Museum of Natural History, Gainesville, U.S.A.) for giving us access to porcellanid material and photographs, and for hosting us. We are also indebted to C.H.J.M. Fransen and K. van Dorp, (Naturalis Leiden) for giving us access to porcellanid material. We also thank S. Sereda for inking our drawings in pencil. We thank H.A. Lessios (STRI), E. Campos (Universidad Autónoma de Baja California, México) and an anonymous reviewer for comments that helped improve this manuscript.