Spinophallus coronatus (Gosliner, 2011)

Description

Known from a single 28 mm long, 7 mm wide holotype. The general body colour is whitish with a "V"-shaped maroon patch on the head. Maroon spots are present along the parapodial margins. The entire dorsal and lateral surfaces are ornamented with scattered irregular yellow spots and a few whitish patches. The ventral surface is pale pink with a series of large yellowish and maroon spots on the foot.

The cephalic shield is roughly rectangular with an indented but blunt, quadrangular anterior end, and terminates posteriorly with an elongate, rounded papilla. The posterior shield is slightly rounded anteriorly and ends in an elongate conical posterior projection. Its two lateral posterior lobes are elongate and simply rounded; the left lobe is longer than the right. Like Spinophallus falciphallus, the penis is armed — uniquely so within the group — and the apex of the penial papilla bears a ring of rounded tubercles (the source of the species name). Two additional regions of spines occur anterior and posterior to the penial papilla.

Distribution

Known only from the Philippines. Type locality: Mainit Bubbles, Mabini, Batangas Province, Luzon, Philippines (12 m). Found on coral rubble at 15 m depth, sympatric with Spinophallus falciphallus.

Etymology

From Latin corona ("crown"), referring to the ring of rounded tubercles at the apex of the penial papilla, which resembles a crown.

Remarks

Originally described as Philinopsis coronata, but transferred to Spinophallus by Zamora-a 2017 revision of Aglajidae based on molecular phylogenetic analysis. Externally and anatomically very similar to Spinophallus falciphallus, but with more yellow pigment and less maroon, and a more elongate posterior projection of the posterior shield. The pattern of penial armature is the most reliable diagnostic character separating the two species. Originally described in Gosliner T. 2011 Zootaxa 2751: 1-24.

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References

• Philinopsis coronata n.sp., GOSLINER T. (2011). Six new species of aglajid opisthobranch mollusks from the tropical Indo-Pacific. Zootaxa. 2751(1). https://doi.org/10.11646/zootaxa.2751.1.1
• Philinopsis coronata, Terrence Gosliner, Ángel Valdés and David Behrens. (2018). Nudibranch and Sea Slug Identification Indo-Pacific 2nd Edition. New World Pubns Inc.