Phyllidiella pustulosa
A common Indo-West Pacific nudibranch revealed as a species complex.
Phyllidiella pustulosa, also called the pustulose wart slug, pimpled phyllidiella, or pustulose phyllidiella, is a dorid nudibranch belonging to the family Phyllidiidae. This sea slug is among the most frequently encountered nudibranchs across the tropical Indo-West Pacific, although genetic analysis of the CO1 gene indicates it actually represents a species complex.
Originally described from specimens collected in Timor, this nudibranch changes in appearance as it grows. Throughout development, three central clusters of tubercles—usually pink—remain consistent, though they are fused together in juveniles and become separate in larger individuals. These tubercles may be pink, green, or white. The intensity of pink and green-grey tones might be linked to diet and the time elapsed since the animal last fed. Additional identifying traits include a pale pink mantle edge, broad triangular oral tentacles with black tips, and rhinophoral clubs bearing 22 to 26 lamellae in specimens over 35 millimeters.
Quick Facts
- Taxon
- Phyllidiella pustulosa
Facts from the source article.
Lore & Background
This species was originally described from specimens collected in Timor. It is one of the most common nudibranchs throughout the tropical Indo-West Pacific, but a study using DNA sequencing of the CO1 gene has shown that it is a species complex, meaning what was once considered a single species likely comprises multiple distinct species. The nudibranch changes appearance as it grows, yet three median clusters of usually pink tubercles remain consistent, though they are amalgamated in juveniles and become separated in large animals. These tubercles can range in color from pink to green to white, and the intensity of pink and green-grey tones may possibly be related to diet and the length of time since last feeding. Other distinguishing features include the pale pink edge of the mantle, broad triangular black-tipped oral tentacles, and rhinophoral clavus with 22 to 26 lamellae in specimens greater than 35 mm.
Reader's Guide
Phyllidiella pustulosa holds significance as one of the most frequently encountered nudibranchs across the tropical Indo-West Pacific, making it a key species for ecological and taxonomic studies. However, its status as a species complex—revealed through DNA sequencing of the CO1 gene—underscores the importance of molecular methods in uncovering hidden biodiversity. The species' variable coloration, with tubercles ranging from pink to green to white, and the possible link between color intensity and diet or feeding history, highlight the complexity of phenotypic plasticity in sea slugs. Its distinctive features, such as the pale pink mantle edge and black-tipped oral tentacles, aid in field identification, while the documented mimicry by a flatworm (referenced in the further reading) points to broader evolutionary interactions. The species' legacy lies in challenging traditional morphological taxonomy and emphasizing the need for genetic analysis in understanding nudibranch diversity.
Did You Know?
- Phyllidiella pustulosa was described from specimens collected in Timor.
- Three median clusters of usually pink tubercles are amalgamated in juveniles and separated in large animals.
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