On a new commensal species of Aliaporcellana from the western Pacific (Crustacea, Decapoda, Porcellanidae)
ZooKeys
On a new commensal species of Aliaporcellana from the western Pacific (Crustacea, Decapoda, Porcellanidae)
Alexandra Hiller 0
Bernd Werding
0 Smithsonian Tropical Research Institute , Apartado 0843-03092, Panamá , República de Panamá 2 Institut für Tierökologie und Spezielle Zoologie der Justus-Liebig-Universität Giessen , Heinrich-Buff-Ring 29 (Tierhaus), D-35392 Giessen , Germany
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. The porcellanid genus Aliaporcellana was established by Nakasone and Miyake (1969) for a group of Indo-West Pacific species previously assigned to Porcellana Lamarck and to one of three natural groups within Polyonyx Stimpson, designated by Johnson (1958) as the P. denticulatus Paul'son 1875, group. A diagnostic character considered
eol>Crustacea; Porcellanidae; Aliaporcellana; new species; Indo-West Pacific; commensalism; adaptation; sponge- and octocoral-dwelling
Introduction
by
Nakasone and Miyake (1969)
to raise Aliaporcellana is the dactylus of all walking
legs bearing two or more distinctively well-developed fixed spines. Aliaporcellana
contained nine species until
Haig (1978)
restricted the genus to the species of the Polyonyx
denticulatus group, which now includes the type A. suluensis (Dana 1852), A. pygmaea
(de Man 1902) and A. telestophila
(Johnson 1958)
, and the species described by
Nakasone and Miyake (1969)
, A. kikuchii. A fifth species, A. taiwanensis, was subsequently
described by
Dong et al. (2011)
.
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.
Material and methods
We found the new species in material collected in the Philippines by G. Paulay [Florida
Museum of Natural History, Gainesville, U.S.A. (UF)] and in Indonesia by C.H.J.M.
Fransen [Naturalis Leiden, The Netherlands (RMNH)]. The holotype is deposited in
the National Museum of Natural History, Philippines (NMCR). Color photographs
of the holotype and of the live crab in the field were provided by G. Paulay, and were
included in the description. Measurements of carapace length and width (in mm) of
type individuals follow collection information.
Results
Systematic account
Family Porcellanidae
Aliaporcellana spongicola sp. n.
http://zoobank.org/21BCF647-FA9C-43C6-B604-5FCBD474643D
Figures 1–5
Material. Holotype: female (ovigerous), NMCR 4966, ex UF 43328, Philippines,
Oriental Mindoro Province, Mindoro, Puerto Galera, off Pt W of Bayanar Beach,
13.5118°N 120.9088°E, 10–13 m, sand slope, coll. G. Paulay, 02.04.2015, 6.8 × 7.0
mm. Paratypes: 2 females (ovigerous), UF 43328, same collection data as holotype, 7.4
× 7.6 mm, 5.2 × 5.2 mm;1 female (ovigerous), UF 42943, Philippines, Oriental
Mindoro Province, Mindoro, Puerto Galera, Batangas Channel, 13.5199°N 120.9604°E,
11 m, lagoon sand slope with sponge, coll. G. Paulay, 12.04.2015, 6.2 × 6.8mm; 2
males, 1 female (ovigerous), RMNH.CRUS.D.57287, Indonesia, SW Sulawesi,
Spermonde Archipelago, Bitung, sta. 17, 20 m, from large grey folious sponge, cleaning
station, coll. C.H.J.M. Fransen, 30.10.1994, 4.8 × 4.4 mm, 3.3 × 3.0 mm, 5.2 × 4.8 mm.
Description. Carapace rounded (Figures 1, 2), considerably variable in form and in
length-width ratio; larger females with carapace broader than long (ratio < 1), smaller
individuals with carapace relatively longer than broad (ratio > 1); dorsal surface convex,
glossy, with faint, transverse striae on branchial and intestinal regions; cervical grooves
gently depressed. Front (Figures 1, 2) broad, slightly produced beyond eyes, weakly
trilobate, somewhat deflexed; frontal lobe visible in dorsal view, grooved, overreaching
lateral ones. Distal margin of entire front lined with row of rounded, upwardly directed
small spines (Figure 3a), the largest on supraocular edges (...truncated)