Class CHILOPODA

Centipedes are relatively large animals, 5mm to 80mm or more, distinguished by having the first pair of legs modified as poison claws (forcipules) which lie under the head and 15 to more than a hundred further trunk segments (always an odd number) each bearing a single pair of legs. Unlike the mostly herbivorous millipedes, centipedes are carnivores and often very active when disturbed. In the orders Scutigeromorpha and Lithobiomorpha (and the Australasian Craterostigmomorpha) the youngest (larval) stages have fewer leg pairs than adults but in Scutigeromorpha and Geophilomorpha the animals are born with a complete set (which may vary as between sexes and within a species); this can be useful in the identification of geophilomorphs.

About 3,000 species of centipedes have been described worldwide of which about 1,000 are members of the order Geophilomorpha which contains a number of littoral species.

Order SCUTIGEROMORPHA

These are very active animals with 15 pairs of extremely long legs and compound eyes which includes the so called “house centipede” Scutigera coleoptrata Linné, 1758.

Pallas (1772) wrote of Julus araneoides (Scutigera coleoptrata) as “insectum pelagicum ab amico mihi Navarcho quodam inter susceptos in Oceano Atlantico Fuci natatis fasciculos”. Scutigeromorphs are seen in coastal localities in various parts of the world. In Jersey S. coleoptrata has been collected amongst large pebbles above high water mark and seems to occur in similar situations on the French Channel coast (Barber 2006).

Order LITHOBIOMORPHA

These are relatively short bodied, active species with 15 leg pairs in the adult and usually, although not always, with one or more ocelli on each side of the head.

In the British Provisional Atlas (Barber & Keay 1988) some 10 lithobiomorphs are all recorded at least once from sea shore sites. These include both the ubiquitous Lithobius forficatus (Linné, 1758) and also L. melanops Newport, 1845, a species also common in gardens and similar disturbed sites. None of the species, however, appear to be truly halophilic. Takano (1980) shows Lithobius ellipticus Takakuwa 1939 as intertidally recorded in his Fig. 4.

Order SCOLOPENDROMORPHA

Scolopendromorphs include the so called “giant centipedes” of the tropics as well as other species. Typically they have 21 or 23 leg pairs, are relatively short bodied and active and may be blind or have a four ocelli on each side.

Cryptops hortensis (Donovan, 1810) was listed as one of their species from shore sites by Barber & Keay (1988) but not as a true halophile, however Demange (1963) does describe what appears to be the first halophilic scolopendromorph, Campylostigmus plessisi from Nouvelle Caledonie.

Order GEOPHILOMORPHA

Long bodied, blind species with numerous leg pairs (31 to more than a hundred) sometimes called wire-centipedes or wireworms.

Possibly up to nine families of this order contain apparently halophilic species and within these are 17 (probably more) genera containing halophilic species (Table 1). The total number of halophilic geophilomorphs recorded in a recent list (Barber, 2009) is 45. Most of these are from Europe, Western United States, the Caribbean, South America, Japan and Australia/New Zealand. There are few records from the Atlantic coast of USA or from Canada, very few African records and little from much of Asia other than Japan, Korea and Taiwan. It is highly improbable that there are no species occurring on these coasts. In addition it is possible that some species for which no habitat data is given (e.g. for California / Baja California, South Africa, New Zealand) may well be halophilic and also finding littoral species in some habitats (e.g. rock crevices) is not always easy. An estimate of 100 plus species from around the world seems reasonable. There are certainly reports in the literature of seashore centipedes where the species was not identified: Cape Verde Is, Galápagos, Colombia, Panama, Costa Rica (Crossland, 1929, Polhemus & Evans, 1969). Probably there are as yet undescribed littoral species in collections and it is quite likely that some described species where habitat was not given may well be littoral.