Bythograea thermydron, WILLIAMS, 1980

Martin, Joel W. & Haney, Todd A., 2005, Decapod crustaceans from hydrothermal vents and cold seeps: a review through 2005, Zoological Journal of the Linnean Society 145 (4), pp. 445-522 : 490-491

BYTHOGRAEA THERMYDRON WILLIAMS, 1980

Type locality: East Pacific Ocean, EPR, Galapagos Rift, Mussel Bed ; 0°48.89′N, 86°09.12′W; 2488 m .

Known range: Eastern Pacific Ocean, found associated with (and the most dominant crab species at) most hydrothermal vent sites in the EPR between 21°N and 18°38′S and on the Galapagos Rift, but not known to date from vents south of the Easter Microplate (31– 32°S) on the southern EPR ( Guinot & Segonzac, 1997; Guinot & Hurtado, 2003).

Material: type locality; Alvin dive 887; 12 February 1979; USNM 172830 (holotype male), USNM 172832 (paratypes, 4 males, 1 female), MCZ (paratype, 1 male), AHF / LACM (paratype, 1 male), BMNH (paratype, 1 male), MNHN (paratype, 1 male), WHOI (paratype, 10 males, 3 females), ( Williams, 1980). –type locality; 2493 m; Alvin dive 880; 21 January 1979; WHOI (paratype, 1 male) ( Williams, 1980).

– Galapagos Rift, Mussel Bed ; 0°48.89′N, 86°09.12′W; 2483 m; Alvin dive 888 ; 13 February 1979; Paratypes: 1 male, RMNH ; 11 males, 29 females, WHOI ( Williams, 1980).

– Galapagos Rift, Rose Garden area ; 0°48.25′N, 86°13.48′W; 2447 m; Alvin dive 890 ; 15 February 1979; MCZ (paratype, 1 female), AHF / LACM (paratypes, 2 females), BMNH (paratypes, 2 females), RMNH (paratypes, 2 females) , MNHN (paratype, 1 female) , WHOI (paratypes, 16 females) ( Williams, 1980) . − 0°48.25′N, 86°13.48′W; 2457 m; Alvin dive 894; 19 February 1979; WHOI (paratypes, 6 females) ( Williams, 1980) . − 0°48.25′N, 86°13.48′W; 2482 m; Alvin dive 895; 20 February 1979; WHOI (paratype, 1 male) ( Williams, 1980) . − 0°48.25′N, 86°13.48′W; 2460 m; Alvin dive 896; 21 February 1979; USNM 172831 (allotype female) , USNM 172833 (paratypes, 2 males, 4 females), WHOI (paratypes, 1 male, 31 females) ( Williams, 1980).

– Locality not recorded; depth unknown; Alvin dive unknown; date unknown; WHOI (paratype, 1 female) ( Williams, 1980) .

–southern EPR, Fromveur hydrothermal vent site; 18°25.96′S, 113°23.35′W; 2622 m; NAUDUR, Nautile dive ND9-1-2B; 14 December 1993; MNHN-B 24916 (non-type, 1 juvenile) ( Guinot & Segonzac, 1997). –Animal Farm hydrothermal vent site; 18°36.50′S, 113°23.98′W; 2673 m; NAUDUR, Nautile dive ND12- 7-3B; 17 December 1993; MNHN-B 24899 (non-types, 2 males, 2 females) ( Guinot & Segonzac, 1997). –Animal Farm hydrothermal vent site; 18°36.50′S, 113°23.98′W; 2673 m; NAUDUR, Nautile dive ND12- 7-6B; 17 December 1993. MNHN-B 25391 (non-type, 1 juvenile) ( Guinot & Segonzac, 1997).

– Galapagos Rift, Rose Garden vent site; 2500 m; February, November and December 1979; 215 crabs collected from traps ( DeBevoise, Childress & Withers, 1990).

– EPR, Riftia-Field hydrothermal vent site; 09°50.72′N, 104°17.56′W; 2532 m; MISSION HOT 96, Nautile , dive 23; 11 March 1996; non-types, 32 males, depository not named, likely MNHN ( Guinot & Segonzac, 1997) .

– EPR, 12– 13°N, Actinoir, Pogonord and Parigo sites; 2430 to 2610 m; BIOCYARISE 1984 cruise; 38 total specimens (see Guinot, 1988) . – EPR; 12°48′N, 103°57′W; Nautile; November and December 1987; number of specimens not given ( Sanders & Childress, 1992) . – EPR; 12°48.675′N, 103°56.386′W; 2640 m; Hydrothermal Ecosystem Research Observatory ( HERO) expedition, Nautile; October–November , 1991; number of specimens not given ( Boetius & Felbeck, 1995). –same general area , HERO 1991 and 1992 cruises and DSV Alvin dives, from the following vent sites: Elsa, Genesis, Julie, Parigo (numbers of crabs not given) ( Gorodezky & Childress, 1994) . – EPR, Totem hydrothermal site; 12°48.80′N, 103°56.45′W; 2640 m; MISSION HOT 96, Nautile , dive 28; 17 March 1996; non-types, 3 females, depository not named, likely MNHN ( Guinot & Segonzac, 1997) . – EPR, Genesis site; PHARE’02 expedition to 13°N vent sites; 2600 m; May 2002, number and fate of specimens not given ( Sanglier et al., 2003) .

– EPR, collapse pit site; 20°50′N, 109°00′W; 2600 m; May 1982; from traps; 19 specimens ( DeBevoise et al., 1990) .

Remarks: As the first species of true (brachyuran) crab reported from hydrothermal vents as well as the species for which the family Bythograeidae was erected, B. thermydron understandably has been the subject of a large number of studies, not all of which are listed here. Hessler & Smithey (1983) provided comments on its habitat and ecology, some of which are also summarized by Guinot (1997, in Desbruyères & Segonzac, 1997). Van Dover et al. (1985) described planktotrophic larval development and included a photograph of an ovigerous female (p. 224, fig. 1B). Van Dover, Franks & Ballard (1987) used crab densities to predict vent locations, and although they mentioned only the genus name we assume, based on the locality, that the species was B. thermydro n. Other studies on this species include investigations of its digestive enzyme activities ( Boetius & Felbeck, 1995), oxygen consumption and regulation ( Gorodezky & Childress, 1994), effects of temperature and pressure on oxygen consumption ( Mickel & Childress, 1980, 1982a; reviewed by Somero, 1992) and on heart rate ( Mickel & Childress 1982b; Airriess & Childress, 1994), foregut morphology ( Martin, Jourharzadeh & Fitterer, 1998a), general physiology ( Childress & Fisher, 1992), mouthpart morphology ( Factor, Van Dover & Williams, 1982), ability to detoxify sulphide ( Powell & Somero, 1986; Vetter et al., 1987), oxygen consumption rates and their regulation ( Childress & Mickel, 1985), haemocyanin structure and function ( Terwilliger & Terwilliger, 1985; Lallier et al., 1998; Zal et al., 2002), hyperglycemic hormones ( Toullec et al., 2002), haemocyanin activity and oxygen affinity ( Arp & Childress, 1981; Sanders, Art & Childress, 1988; Sanders & Childress, 1992), dietary carotenoids ( DeBevoise et al., 1990), predation on other vent organisms ( Voight, 2000, citing Jollivet 1993 (see also Micheli et al., 2002, and Childress, Felbeck & Somero, 1987)), enzyme activities ( Hand & Somero, 1983), haemocyanin protein structure ( Sanglier et al., 2003), larval development ( Van Dover, Williams & Factor, 1984; Van Dover et al., 1985), colonization of new vents ( Shank et al., 1998a), occurrence in a Stauromedusae-dominated region ( Lutz et al., 1998), ontogeny of vision and visual metamorphosis ( Jinks et al., 2002), radiometric ages ( Bennett & Turekian, 1984), osmotic and hydromineral regulation ( Martinez et al., 2000, 2001), temporal patterns in egg development ( Perovich et al., 2003) and development and swimming behaviour of megalopal stages (e.g. Epifanio et al., 1999). Epifanio et al. (1999) successfully reared the species from late larval (megalopal) stages through metamorphosis and the first several juvenile stages. Megalopal and early crab stages were also briefly described by de Saint Laurent (1988), and food sources of megalopae and early juveniles were studied using stable isotopes by Dittel, Epifanio & Perovich (2005).