Cancer eques Aubert de la Chesnaye des Bois, 1759

Low, Martyn E. Y. & Ng, Peter K. L., 2012, The identities of Cancer arenarius Toreen, in Osbeck, 1765, Cancer arenarius Zimmermann, in Cavolini, 1792, Cancer (Mantis) arenarius Herbst, 1793, and Cancer (Gammarellus) arenarius Herbst, 1793, and other names associated with the genus Ocypode Weber, 1795 (Crustacea: Amphipoda, Decapoda,, Zootaxa 3398, pp. 40-57 : 48-49

Cancer eques Aubert de la Chesnaye des Bois, 1759 : a junior subjective synonym of Ocypode cursor ( Linnaeus , 1758) ( Decapoda : Brachyura: Ocypodidae )

The name “ cancer eques ” (Latin) or “ cancer (h) ippeus ” (Greek) meaning “horse crab” has been in use for the species commonly known as the ghost crab in the Mediterranean for over 25 centuries since the days of Aristotle ( Voultsiadou & Vafidis 2007: 108). Belonii (1553: 361, 362) used the Latin term “eqves cancer” and provided a detailed description of this species, which was repeated by later authors (e.g., Aubert de la Chesnaye des Bois 1759: 417; Gesneri 1558: 194; Latreille in Biot et al. 1818: 197).

In an entry on the Mediterranean ghost crab in his zoological dictionary, François-Alexandre Aubert de la Chesnaye des Bois (1759: 416, 417) used the Latin name Cancer eques and included the observations of Belonii (1553: 361, 362) and Gesneri (1558: 194, 195). As indicated by the final portion of the title of Aubert de la Chesnaye des Bois’ (1759) work, it was intended to be “… suivant les différentes méthodes ou nouveaux systêmes de Messieurs Linnaeus, Klein & Brisson ”. Aubert de la Chesnaye des Bois (1759) was thus not simply republishing the work of earlier authors and translating names into Latin, but was clearly adopting these names and using them according to the “new classification systems of Linnaeus, Klein and Brisson”. Aubert de la Chesnaye des Bois (1759) is the first post-1758 author to have used the name Cancer eques within the binomial nomenclatural framework. Cancer eques Aubert de la Chesnaye des Bois, 1759 , is thus an available name.

Aubert de la Chesnaye des Bois (1759: 417) described Cancer eques as follows:

“ Cancre Cavalier, en Grec 1ππOὺς, en Latin Cancer eques . En Allemand, dit Gesner [i.e. Gesneri 1558: 194, 195], Ein Reuter; en Italien Cavalliero ou Caballiero. C’est un Amphibie, selon Belon [i.e. Belonii 1553: 361, 362]. Dans les chaleurs de l’été, sur le midi, ils sortent en troupe de la mer, pour passer le reste du jour au soleil, ou à l’ombre, ou peutêtre pour n’être pas dévorés des poissons. Ce Naturaliste, en partant de Memphis pour Jerusalem, marque que sur les confins de l’Egypte il en vit qui retournoient à la mer, & couroient d’une si grande vitesse, qu’il n’étoit pas possible de les atteindre. Il ajoute qu’un Lézard qui étoit à l’ombre sous une plante, nommée Ambrosie, ayant apperçu un de ces Cancres, le poursuivit, & que ce Cancre, qui paroissoit plutôt voler que courir, lui échapa. Ces sortes de Cancres sont si petits, dis Gesner [i], qu’il n’y a rien à manger ”. [The ‘Knight Crab’; in Greek ‘the horse’; in Latin Cancer eques . In German, according to Gesner [i.e. Gesneri 1558: 194, 195], ‘The Knight’; in Italian ‘Knight’. This is an amphibian, according to Belon [i.e. Belonii 1553: 361, 362]. In the heat of summer, at about noon, they come in from the sea in groups to spend the rest of the day in the sun, in the shade, or perhaps to avoid being eaten by fish. This naturalist [Belonii], observed them returning to the sea, along the shores from Memphis to Jerusalem, marking the borders of Egypt; running with such great speed that it was not possible to catch them. The same commentator added that a lizard hiding under the shade of a plant called ‘Ambrosia’ pursued this crab which seemed to fly rather than run, and evaded the lizard. According to Gesner[i], these crabs are so small in size that they are not worth eating.]

Grmek & Guinot (1965: 55) discussed that the “eques cancer” of Belonii (1553) is conspecific with Ocypode cursor ( Linnaeus, 1758) . Garassino et al. (2010: 142) also state that Ocypode cursor ( Linnaeus, 1758) , is the only species of the genus Ocypode known to live in the Mediterranean area, as mentioned by Aubert de la Chesnaye des Bois (1759: 417), and in the area in which Belonii (1553) conducted his observations (see Kitto 1852: 492). Cancer eques Aubert de la Chesnaye des Bois, 1759 , should therefore be regarded as a junior subjective synonym of Ocypode cursor ( Linnaeus, 1758) .