Pagurus alatus Fabricius 1775
- Dataset
- Hermit crabs (Decapoda: Crustacea) from deep Mauritanian waters (NW Africa) with the description of a new species
- Rank
- SPECIES
Classification
- kingdom
- Animalia
- phylum
- Arthropoda
- class
- Malacostraca
- order
- Decapoda
- family
- Paguridae
- genus
- Pagurus
- species
- Pagurus alatus
discussion
Remarks. Our specimens coincide with the descriptions and figures given by Ingle (1993). The taxonomic status of P. alatus, P. excavatus and P. variabilis has been controversial for many years. The differences between P. excavatus and P. variabilis were established by A. Milne-Edwards & Bouvier (1900). Following that opinion, Selbie (1921) indicated that the most reliable features to separate both species were the number of unpaired pleopods in males (three in P. variabilis and four in P. excavatus) and the length of the dorso-outer process of the antennal peduncular segment 2 that reaches, or passes, the base of the terminal joint in P. alatus but not in P. excavatus. Forest (1955: 109) also followed this differentiation, considering P. excavatus to be identical to P. alatus (the latter name having priority) and different from P. variabilis. This author also indicated the presence of two Pagurus (as Eupagurus) groups in West Africa, the first group including P. alatus, with four unpaired pleopods in males (a feature of the current concept of P. excavatus), and the second group, including P. variabilis, with three unpaired pleopods in males (a feature of the current concept of P. alatus). Forest opinion was shared by Zariquiey (1968). Based on Selbie (1921), Ingle (1985) indicated that there were no consistent records of P. excavatus north of the southern part of the Bay of Biscay. Taking into account that P. alatus was described after material collected in Iceland, Ingle concluded that P. alatus and P. excavatus were two different species and reinstated P. excavatus as a valid species. In addition, Ingle (1985) considered P. variabilis, whose distribution was more boreal, to be a junior subjective synonymy of P. alatus. Ingle (1993) provided a complete synonymy for P. alatus and P. excavatus, which is currently accepted. Nevertheless, the report of P. alatus in Forest (1955) from Loos Islands and Zariquiey (1968) from the Iberian Peninsula should be definitively included in P. excavatus.
distribution
Distribution. Eastern Atlantic, from Iceland, Norway, the Shetland Islands and the North Sea southwards to Mauritania, including the Canary Islands and the Mediterranean Sea (d’Udekem d’Acoz 1999). The record from Loos Islands (Guinea) (Forest 1955) belong to P. excavatus (see remarks). Bathymetrical range varies from 5 – 10 m (Pipitone & Arculeo 2003) to 1430 – 1505 m (García Raso 1996), although the species is mainly found around 150 m depth (d’Udekem d’Acoz 1999). Further records were from the Bay of Biscay (Urzelai et al. 1990; Serrano et al. 2006; Cartes et al. 2007; Sánchez et al. 2008; Serrano et al. 2011), off Portugal (Monteiro et al. 2001) and the Mediterranean Sea (Koçak et al. 2001; Abelló et al. 2002; Biagi et al. 2002; Pipitone & Arculeo 2003; Colloca et al. 2004; Company et al. 2004; Ungaro et al. 2005; Mura et al. 2006; Ates et al. 2006; Fanelli et al. 2007; Cartes et al. 2009; Follesa et al. 2009; Papiol et al. 2012).
materials_examined
Material examined. MU 57, 430 – 406 m, (1); MU 120, 109 – 105 m, (1); MU 142, 109 – 112 m, (1); MU 158, 80 – 98 m, (2); MU 207, 88 – 117 m, (1); MU 260, 101 – 120 m, (1); MUBV 20, 155 m, (5); MUBV 21, 107 – 109 m, (31). Males: 3.06 – 6.56 mm, females: 3.10 – 3.40 mm, ovigerous females: 3.01 – 4.03 mm Habitat. This species is characteristic of bathyal muds (d’Udekem d’Acoz 1999; Follesa et al. 2009; Mura et al. 2006), but is also reported on sand (Pipitone & Arculeo 2003) and on bottoms of sand, silt, coarse sands and gravel by Serrano et al. (2011).
Name
- Homonyms
- Pagurus alatus Fabricius 1775