GONZALES & GOSLINER: NEW SPECIES OF PHILINE FROM THE INDO-PACIFIC 381 
line aperta clade members. Our analysis shows strong support for the Philine aperta clade, when 
additional Philine are included. A second phylogeny was recently published by Ohnheiser and 
Malaquias (2013) that focused upon COI sequences from North Atlantic species. Their study also 
shows strong support for the Philine aperta clade, but includes only two members of this group, 
P. quadnpartita Ascanius, 1772 and P finmarchica (M. Sars, 1859). 
The present molecular study includes four additional species in Philine aperta clade: P. habei, 
P verdensis, P pittmani andP. dentiphallus. In our analysis, P habei and P. verdensis are sister taxa 
to each other and are collectively the sister taxon to the clade that includes P aperta, P quadripar- 
tita, P paucipapillata, P. sp. 1 (from Australia), and P angasi. These taxa also formed a clade in 
Krug et al.’s (2012) study, but in our study P quadripartita and P. aperta are more basally situat¬ 
ed than in the previous study. However, these relationships are weakly supported. The two addi¬ 
tional species, P pittmani and P. dentiphallus, are most closely related to P, auriformis, and collec¬ 
tively these three taxa are sister to P. orientalis. In Krug et al. (2012), P orientalis was sister to the 
clade containing P. paucipapillata, P. sp. 1, P aperta, P quadripartita, and P, angasi. While there 
are slight variations in the relationships, the same general patterns of relationship persist in the 
present study, when additional taxa are added. Morphological studies also support the relationship 
of P. dentiphallus with P auriformis, since both of these species, together with P. fenestra Price, 
Gosliner, and Valdes, 2011, are the only members of the P. aperta clade with a radula with an outer 
lateral tooth and gizzard plates with a solid central bar rather than simple paired pores. No molec¬ 
ular data are available P fenestra. Philine pittmani is sister to P. dentiphallus and P. auriformis. 
It is unusual for members of this clade in that its paired gizzard plates have only a single pore, but 
its radula lacks outer lateral teeth, unlike P. auriformis and P. dentiphallus. 
In our analysis, P. hearstorurn and P. acuticuada are sister to each other and collectively are 
sister to the P. aperta clade. As noted above, P alba and P. alboides have morphological similari¬ 
ties to P. hearstorurn and P. acuticauda, but no material suitable for molecular sequencing is avail¬ 
able for the two former species. 
Another weakly supported finding from this study is that P. orca Gosliner, 1988 and P. rubra- 
ta Gosliner, 1988, are both nested at the base of the Aglajidae rather than within the rest of the Phi¬ 
line species. It is interesting to note that these species have distinctively pigmented bodies, unlike 
other Philine species, as well as a muscular gizzard that lacks plates. A pigmented body and lack 
of gizzard plates are also characteristics of the Aglajidae. These features suggest that these species 
of Philine may be more closely related to Aglajidae than to Philinidae. Another species that has a 
pigmented body, lacks gizzard plates and has a similar radular morphology to P. orca and 
P. rubrata is P. quadrata (Wood, 1839). Philine quadrata was studied by Ohnheiser and Malaquias 
(2013), but only its COI mitochondrial sequences were studied and no molecular comparisons can 
be made at this time. 
The phylogeny presented here strongly suggests that gizzard plates have been lost at least 
twice in independent lineages of Philinacea. Within Philine, P. acuticauda lacks gizzard plates 
while its sister taxon, P. hearstorurn still has well-developed plates. The species of Philine that are 
nested with the lineage that also includes the Aglajidae also entirely lack gizzard plates, while the 
outgroup, Scaphander, has well-developed gizzard plates. This suggests a second loss of plates in 
this lineage, independently fi'om that found in P acuticauda. 
The present study presents data that further documents the high species richness of the Indo- 
Pacific tropics, especially within the deeper waters of the Coral Triangle. The Philine aperta clade, 
appears to be particular rich in its diversity. Phylogenetically, this clade has been reasonably well 
studied, but examination of additional genes will hopefullty increase the robustness of support for 
various lineages within the clade as more of its diversity is discovered. 
