VAN SYOC ET AL.: SEVEN NEW BARNACLES FROM THE PHILIPPINES 
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Etomology.— Named for the type loeality, the Verde Island Passage (VIP) and the Latin 
-ensis, belonging to or fi-om, literally Acasta from VIP (Verde Island Passage). 
Distribution. — Known only from the type locality in the Verde Island Passage, Philippines. 
Species comparisons. — Acasta hirsuta Broch, 1916, A. purpumta Darwin, 1854, A. gre- 
garia Utinomi, 1959, Euacasta micro foramina Rosell, 1970, and Archiacasta spinitergum Broch, 
1931 are Acastinae species known from the western Pacific which have been recorded living on 
gorgonian hosts and are similar to A. vipensis morphologically with a flat basis with shallow 
grooves aligned with plate sutures. The plates also have small, short spines, similar to those of 
A. vipensis. However, A. purpurata and Euacasta microforamina have fenestra, small openings at 
the basal end of wall plate sutures, which are lacking in the other species. 
The scutum of^. vipensis has a more rounded basi-tergal angle than A. hirsuta and it lacks an 
adductor muscle pit which is quite obvious, though shallow, in^. hirsuta. The latticed external sur¬ 
face of the scutum of A. vipensis is also much more pronounced than the less obvious longitudinal 
ribs in^. hirsuta. The scutum exterior of A. gregaria has growth ridges with fluted margins, rather 
than the latticed appearance. In addition, the tergal spur of A. vipensis is longer and slightly nar¬ 
rower (less than half the width of the basal margin) than that of hirsuta, A. gregaria, and Archi- 
acasta spinitergum (about half the width of the basal margin). 
Both A. hirsuta and^. vipensis have small spines or “teeth” on the three basal segments of cir- 
ms IV, these are absent in Archiacasta spinitergum, however the spines in A. hirsuta are arranged 
in a more or less linear fashion, horizonally across the segments, whereas those in A. vipensis are 
less organized and spread down most of the face of the segments. Euacasta microforamina has 
much larger spines. Spines are lacking in Archiacasta spinitergum. Utinomi (1959) did not have a 
body in the type material of A. gregaria, so he could not determine the details of the cirral mor¬ 
phology. 
Daiwin (1854) listed the host of A. purpurata as the gorgonian genus Isis, in the family Isidi- 
dae. Rosell noted the host taxon of Euacasta microforamina as a “plexaurid gorgonian”. Broch 
(1916) identified the host of A. hirsuta as Euplexaura, a plexaurid genus. He noted the host of 
Archiacasta spinitergum only as a gorgonian (Broch 1931). Acasta vipensis has only been found 
on hosts in the genus Menella, in the family Plexauridae. 
Molecular results 
The phylogenetic tree resulting from the COl sequence data for 84 barnacle individuals had 
seven clades representing new species (Fig. 29). Although we intended the COl sequence to sim¬ 
ply serve as an independent line of evidence to the moiphological data for the new species, we 
found that the host families map onto the tree covering sets of 1, 2 and 4 species clades of barna¬ 
cles sequenced for this study. Two of the new species from the Philippines, C. sahangensis sp. nov. 
and C. willhearsti sp. nov. are found living with gorgonians in the family Melithaeidae. Four 
species, C exothobasis sp. nov., C. basicuneata sp. nov., C. margaretae sp. nov., and C. miny- 
rostrum sp. nov., live only on gorgonians in the family Ellisellidae. Acasta vipensis sp. nov. inhab¬ 
its gorgonians in the genus Menella (Plexauridae). The tree shows these data in an obvious graph¬ 
ical fashion. 
Discussion 
Clearly, there is host specificity at the family level for the barnacle species described in our 
study. However, species-level host specificity of gorgonian-inhabiting barnacles is not resolved. 
Carrison-Stone et al. (2013) have presented data that indicates species-level host specificity for 
Conopea calceola (Ellis, 1758) from Portugal (in Eunicella verrucosa, Gorgoniidae) and Conopea 
