CIRRIPEDIA 



193 



TABLE 1 (cont'd) 



Family LITHOGLYPTIDAE 



f Balanodvtes talwanus Utlnoml, 1950. 

 fKochlorine ulula Tomllnson, 1973. 

 f Uthoglvptes bicornis Aurlvllllus, 1892. 

 Lithoglyiptes splnatus Tomlinson and 

 Newman, 1960; Tomllnson, 1973. 

 Lithoglvptes mitis Tomllnson, 1969: Tomllnson, 1973. 

 t L/thog/yptes wllsonl Tomllnson, 1969. 

 fWeknerla reticulata Tomllnson, 1969. 

 Order RHIZOCEPHALA 

 Suborder KENTROGONIDA 

 Family SACCULINIDAE 



"fSaccullna actaeae Guerln<5anlvet, 1911. 

 fSaccullna bipunctata Kossmann, 1872. 

 'fSaccuHna carplllae Guerln-Ganivet, 1911. 

 fSacculina Inconstans Boschma, 1952. 

 fSaccullna punctata Boschma, 1934. 

 I^Saccullnld sp. 



'Systematic hierarchy taken from Bowman and Abele (1982). 

 tSpecles likely to be found at Enewetak Atoll. 

 ^:New Enewetak Atoll records. 



ASCOTHORACICA 



Ascothoraclcans generally have been considered the 

 most primitive barnacles, but there is argument to separate 

 them as a subclass coordinate with the Cirripedia (Gryglcr, 

 1983). The bases for the argument are that the Ascothora- 

 clca have nauplli that lack "frontolateral horns; a relatively 

 anamorphic rather than highly metamorphic development; 

 an ascothoracid larva capable of feeding at all stages 

 rather than a single cyprid stage lacking a complete gut 

 and functional mouthparts; wholly prehensile first antennae 

 rather than ones also provided with cement glands; and 

 natatory thoracic limbs that show no indication of ever 

 having been used as cirri. Furthermore, it has recently 

 been shown that the ascothoraclcan sperm, the most gen- 

 eralized known for the Crustacea, is distinct from that of 

 the remainder of the cirrlpeds" (Newman, 1982). Though 

 the evidence is strong for the separation of the Ascothora- 

 clca from the Cirripedia, no consensus exists. It is included 

 herein for this reason and because only one species has 

 been reported from the Marshall Islands (Utlnoml, 1962). 



Ascothoraclcans are ecto- and endoparasites of various 

 anthozoans and echinoderms. Often highly modified for a 

 parasitic existence, they show little resemblance to the 

 "typical" thoracic barnacle. They lack calcareous plates, do 

 not cement themselves to the substratum, and retain more 

 characteristics of the free-living ancestors of the cirrlpeds 

 than any other group of crustaceans. 



Gorgonolaureus bikiniensis Utinomi, 1962, is the single 

 ascothoraclcan reported from the Marshall Islands. 

 Described as a new genus and species, it is known only 

 from Bikini Atoll and is reported to be a parasite on the 

 gorgonacean Paracis squamata. This shallow- water gor- 

 gonian has not been reported from Enewetak Atoll (Lang 



and Devaney, this volume). The only other described 

 congeneric species is Gorgonolaureus muzikae Grygier, 

 1981, reported from deep water in Hawaii (Grygier, 

 1981b). 



THORACICA 



Thoracicans include the typical barnacles usually recog- 

 nized by their form and the presence of calcareous plates. 

 There are both free-living and symbiotic taxa, and they can 

 be divided morphologically into pedunculate and sessile 

 forms. The pedunculate barnacles (Lepadomorpha) are 

 composed of a peduncle that attaches to the substratum 

 and a capitulum that is usually surrounded by calcareous 

 plates. The sessile barnacles (Verrucomorpha and 

 Balanomorpha) lack the peduncle, and the aperture is 

 guarded by an operculum formed by one or two pairs of 

 calcareous plates. 



Many thoracic barnacles have wide distributional 

 ranges. This is due in part to the majority having plank- 

 tonic larval stages (Newman and Tomlinson, 1974) and 

 some, such as several oceanic lepadomorph species, natur- 

 ally attaching to floating debris. In addition, some of the 

 natural distributions have been greatly extended because 

 certain species tend to "foul" ship bottoms and floating 

 objects and can be carried great distances. 



Six of the nine barnacle species rejxirted from 

 Enewetak Atoll are thoracicans. This high percentage is 

 not unusual because thoracicans are generally larger than 

 species in the other barnacle orders and have a more obvi- 

 ous "barnacle" appearance, thus making them more recog- 

 nizable and liable to be collected. The other three species, 

 belonging to the Acrothoracica, are small, burrow in cal- 

 cium carbonate, and do not have the typical barnacle 



