52 



R. HUYS AND W. LEE 



Although Nicholls (19416) had also questioned the presence of 4 

 inner setae on the PI endopod, assuming that they were only long 

 ornamentation elements, he nevertheless used this feature in his 

 generic key. The wide acceptance of Lang's re-interpretation of the 

 PI exopod, removing the one remaining obstacle to synonymy with 

 L. bulbifera and L. rhodiaca, made most authors overlook another 

 PI character, i.e. the presence of only 4 elements on the distal 

 exopod segment. This pattern is also recorded in the subspecies E. 

 longicauda galapagoensis described by Mielke (1981) from two 

 islands in the Galapagos and in Esola spec, known from a single 

 female collected in North Sulawesi (Mielke, 1997), however, in all 

 other descriptions a consistent number of 5 setae is found. 



There has been substantial debate over the supposed variability of 

 the P4 endopod in the various 'populations' of E. longicauda. Most 

 authors have dismissed the significance of the absence or presence 

 and relative size of the inner seta on the proximal segment (Table 1). 

 The inner seta is completely absent in Willey's (1935) material of L. 

 bulbifera from Bermuda, Sewell's (1940) specimens of L. bulbifera 

 from the Nicobar Islands and the Addu Atoll (Maldive Archi- 

 pelago), Vervoort's (1964) specimens of E. longicauda from the 

 Ifaluk Atoll, E. longicauda galapagoensis from the Galapagos 

 (Mielke, 1981), Wells & Rao's (1987) single female from Havelock 

 Island (South Andaman), and Mielke's (1997) typical form of E. 

 longicauda from Bunaken Island (North Sulawesi). It is represented 

 by a vestigial element in Vervoort's (1964) single male of E. 

 longicauda var. from Ifaluk Atoll and Mielke's (1997) single female 

 of Esola spec, from North Sulawesi. Finally, it is very well devel- 

 oped in the male of L. rhodiaca described from the Aegean Sea 

 (Brian, 1928a)andNoodt's(1955)ovigerousfemaleof£'. longicauda 

 from the Sea of Marmara. The very long seta recorded in this 

 position in L. bulbifera by Norman (1911) proved upon re-exam- 

 ination of the holotype to be based on an observational error (see 

 below). Hamond (1969) illustrated a scar which he interpreted as a 

 socket where a seta had probably broken off. It is our contention that 

 these setal differences do not reflect real variability but (in conjunc- 

 tion with other characters) demonstrate that several closely related 

 and frequently sympatric species have been described under the 

 name E. longicauda. Unfortunately the condition of the P4 in 

 Edwards' (1891) material is somewhat dubious. On the basis of the 

 [0.1.223] setation pattern of the exopod his Taf. Ill-Fig. 21 must 

 either be the P3 or the P4 and not the P2 as labelled (BpII ! ). Edwards 

 is less specific in the accompanying legend which states 'Fuss eines 

 der drei folgenden Segmente' . The presence of only 2 inner setae on 

 the distal endopod segment may indicate that he had figured the P4 

 in which case the inner seta on the proximal segment is very well 

 developed. Edwards' material differs also in the extremely long and 

 slender claw of the endopod (its length being 83% of that of enp-1) 

 and the elongate caudal rami which are slightly swollen in the 

 female, about 1.7 times as long as wide and have ventrally posi- 

 tioned pores. From the lateral habitus view they appear to be even 

 more slender and elongate in the male. These characters in conjunc- 

 tion with the presence of only 4 setae on PI exp-2 and the well 

 developed inner seta of P4 enp- 1 readily differentiate E. longicauda 

 from its congeners. The male is 550 urn long (inferred from the 

 habitus drawing reproduced at x97 magnification). 



Fiers' ( 1 986) single damaged female from Crooked Island (Baha- 

 mas) is likely to be the only reliable record of this species. Willey's 

 (1935) record of Laophonte bulbifera from Harrington Sound (Ber- 

 muda) is zoogeographically closest but his claims that the caudal 

 rami are shortly barrel shaped, being only slightly longer than wide, 

 and that the P4 enp- 1 lacks an inner seta cast doubt on his identifica- 

 tion. The conspecificity of his smaller female displaying a significant 

 disproportion in size (0.42 mm instead of 0.6 mm) and an atypical 



0.022 pattern on the P2 endopod is also highly questionable. Willey 

 (1935) regarded L. bulbifera to be close to L. depressa T. Scott but 

 gave no justification for this relationship. Alheit & Scheibel (1982) 

 also recorded E. longicauda from Harrington Sound but it is un- 

 known whether their identification was based on Willey's or Edwards' 

 description. Finally, Rouch (1962) recorded the species from 

 Pernambuco State in Brazil but gave no evidence to substantiate his 

 identification. 



Esola bulbifera (Norman, 1911) 



Laophonte bulbifera Norman, 1911 

 ? Laophonte rhodiaca Brian 1928a 

 Esola longicauda Edwards, 1891 sensu Hamond (1969) 

 Esola longicauda var. bulbifera Norman, 1911 sensu Holmes & 

 O'Connor (1990) 



TYPE LOCALITY. Lamlash Bay in Firth of Clyde (Scotland). 



Material examined. 



(a) Holotype 9 dissected on slide (BMNH #396.5); leg. J. Murray & 

 A.M. Norman, July 1888; dredging; 



(b) 2 9 9 and 1 6 collected from West Runton, Norfolk (England), at 

 extreme low water, around and under rocks; leg. R. Hamond, 20 

 August 1993; 1 9dissectedon 13 slides (BMNH 1999.984), 1 9and 

 1 6 preserved in alcohol (BMNH 1999.985-986); 



(c) 3 99 and 1 6* collected from Salt Lake (Ardbear Lough), near 

 Clifden, Co. Galway, Ireland; leg. B. O'Connor, July 1980, on 

 Serpula reef; det. J.M.C. Holmes; 1 o dissected on 11 slides 

 (BMNH 1999.987), 3 99preserved in alcohol (BMNH 1999.988- 

 990). 



Other material. National Museum of Ireland, Dublin: (a) sev- 

 eral specimens: Salt Lake, Clifden, Co. Galway; leg. B. O'Connor, 

 July 1980, from Serpula reef (in alcohol); (b) 1 9: Lough Hyne, Co. 

 Cork; leg. J.M.C. Holmes, 23 September 1987, light trap, 5 m (in 

 alcohol); (c) 1 3: Lough Hyne, Co. Cork; leg. J.M.C. Holmes, 08 

 Augustus 1992 (on slide). 



Description. 



female. Body length from anterior margin of rostrum to posterior 

 margin of caudal rami 681 pm (n=5; range: 643-714 pm). Maxi- 

 mum width (181pm) measured at posterior margin of cephalothorax. 



Body (Fig. 1A-B) cylindrical, not dorsoventrally depressed, 

 covered with dense pattern of minute spinules dorsally and laterally. 

 Cephalothorax slightly wider than free somites, posterolateral angles 

 backwardly produced forming lobate extension (Fig. IB); with 

 paired cup-shaped pores both anterodorsally and anteroventrally on 

 either side of rostrum (arrowed in Fig. IB), anterodorsal set partly 

 closed off by fringe of setular extensions; with distinct transverse 

 spinule row dorsally about halfway down the cephalothorax length 

 (Fig. 1A). Posterior margin of cephalothorax and all body somites 

 with row of long setules dorsally and laterally. Posterior margin of 

 body somites with minute spinules laterally and ventrally; ventrola- 

 teral areas of cephalic shield and pleurotergites of pedigerous somites 

 with longer spinules. Pleurotergite of P5-bearing somite narrowest. 



Genital double-somite wide and dorsoventrally flattened; original 

 segmentation marked by bilateral constriction and spinule row 

 arising from transverse surface ridge dorsally and laterally; anterior 

 (= genital) half with large cup-shaped pores laterally, each partly 

 closed off by fringe of setular extensions (Fig. 1C); posterior half 

 with backwardly directed lobate extensions bearing spinular tuft; 

 ventral surface without spinular ornamentation; genital field located 

 near anterior margin (Fig. 1C). Sixth legs forming well developed 

 opercula closing off paired genital apertures; each with outer naked 





