Author: Undescribed

Order: Nudibranchia  Family: Phyllidiidae

Maximum Size: 14 mm

Sightings: Whitsundays

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Phyllidiella sp. 05 Undescribed

Only a single specimen of this species has been sighted so far. Size was approximately 14 mm. The sighting was at Holbourne Island, off Bowen in the Whitsunday Region of the central Queensland coast.

The notum is translucent white with hints of a pinkish tinge. Two longitudinal black lines, one running down each side form a series of three loops by lateral offshoots extending to the mantle edge in four places. These two longitudinal lines are also linked transversely across the notum in four places – one just anterior to the rhinophores, two others across the central portion of the notum and a fourth posteriorly in the region of the dorsal anus. There are some black markings to the mantle margin in several places that might represent sections of a discontinuous band. The white regions of the notum carry distinct separate (not coalesced) tubercles of varying size, some are large and angular. These have opaque white tips.  The rhinophores are relatively large, have diagonal lamellae, black for the majority of their length but seem to become whitish basally.

External appearance would suggest placement in the Phyllidiella genus however it does not seem to fit readily into already described species therefore we are keeping it separated.

As with all phyllidiids, Phyllidiella sp. 05 is a spongivore.

David A. Mullins – August 2023

References:
– Brunckhorst, D. J. (1993). The systematics and phylogeny of Phyllidiid Nudibranchs (Doridoidea). Records of the Australian Museum, Suppl. 16, 1-107.

– Fahrner, A. & Beck, L. A., (2000). Identification key to the Indo-Pacific species of the nudibranch family Phyllidiidae Rafinesque, 1814, including the description of two new species. Archiv für Molluskenkunde 128 (1/2): 189-211.

– Domínguez, M., Quintas, P., Troncoso, J. S., (2007). Phyllidiidae (Opisthobranchia: Nudibranchia) from Papua New Guinea with the description of a new species of Phyllidiella. American Malacological Bulletin 22: 89–117.

– Stoffels, B. E., van der Meij, S. E., Hoeksema, B. W., van Alphen, J., van Alen, T., Meyers-Muñoz, M. A., de Voogd, N. J., Tuti, Y., van der Velde, G. (2016). Phylogenetic relationships within the Phyllidiidae (Opisthobranchia, Nudibranchia). ZooKeys 605: 1–35.

– Papu, A., Bogdanov, A., Bara, R., Kehraus, S., Konig, G., Yonow, N. & Wagele, H. (2022). Phyllidiidae (Nudibranchia, Heterobranchia, Gastropoda): an integrative taxonomic approach including chemical analyses. Organisms Diversity & Evolution. https://doi.org/10.1007/s13127-021-00535-7.