Dykking med Vorte-snegler

Lantas marine liv | Phyllidiidae

Vorte-snegler er lette å få øye på under våre dykkerturer til Koh Lanta og kjennes umiddelbart igjen på den vorteaktige mantelen og fraværet av rygggjeller.

De fleste artene ser like ut og er svarte og hvite, med en mulig tredje farge som vanligvis er gul eller oransje. Noen få arter kan også ha en blekgrønn eller blekblå farge. Hos noen arter kan vorter være forbundet med ryggribber.

Mantelskjørtet dekker foten, og i motsetning til andre nakensnegler er gjellene plassert langs undersiden og siden av kroppen.

Det er to tentakler på oversiden av hodet, kalt rhinophorer, og disse tentaklene brukes til å oppdage vannbevegelser og dufter i vannet, og kan trekkes inn om nødvendig. Vortesnegler har ingen kjever eller tenner, men suger i stedet på maten sin, hovedsakelig svamper.

Vorte-snegler er hermafroditter, noe som betyr at individene har både mannlige og kvinnelige reproduksjonsorganer.

5 arter funnet på denne siden:

Ocellate Phyllidia (Phyllidia ocellata)
Ceylon Phyllidiidae (Phyllidiella zeylanica)
Varicose Wart Slug (Phyllidia varicosa)
Elegant Sea Slug (Phyllidia elegans)
Pimpled Phyllidiella (Phyllidiella pustulosa)

Ocellate Phyllidia

(Phyllidia ocellata)

Phyllidiella ocellata @ Koh Haa

The body colour is highly variable, yellow, orange, brownish or even light grey, with several black and white ocellations (like eye spots on damselfish), which are sometimes connected.

There is considerable individual variation in dorsal patterns in this species, however the most typical dorsal pattern consists of four to ten black rings bordered in white, each with a central gold or white tubercle.

The large tubercles on the dorsum (upper back) are very obvious, and the rhinophores are orange-yellow.

Ceylon Phyllidiidae

(Phyllidiella zeylanica)

Phyllidiella zeylanica @ Koh Haa

The Ceylon Phyllidiidae has numerous ridges of tuberculate which curve to join anteriorly and posteriorly (but may be interrupted).

A single black band (sometimes not complete) encloses both the rhinophores and the anal orifice, and may contain several black markings within the central black ring. The anterior section of this black band is squared, a feature unique to this species.

The foot sole is pale, and the rhinophores are mostly black, with the lower 2 or 3 lamellae being white.

Varicose Wart Slug

(Phyllidia varicosa)

Phyllidia varicosa @ Koh Haa

Capable of changing colours and textures, the Varicose Wart Slug has a generally black under-colour with bluish speckled patches, lines, spots and blotches which contain the yellow and blue warts which can appear to be in rows. Has yellow rhinophores (sensory tentacles behind the head).

The Varicose Wart Slug grows to 7 cm and is a very poisonous species, using its toxins for defence, and has no known predators.

Elegant Sea Slug

(Phyllidia elegans)

Phyllidia elegans @ Koh Haa

The Elegant Sea Slug has a pale coloured foot with a thin black line along the middle. The body warts (tubercles) are light pink, the larger often with yellow tips.

The light pinkish warts may look grey underwater due to loss of red light. The rhinophores (sensory tentacles on the head) often have pale yellow tips.

The Elegant Sea Slug grows to 6.5 cm, feeds solely on sponges and excretes powerful toxins when distressed.

Pimpled Phyllidiella

(Phyllidiella pustulosa)

Phyllidiella pustulosa @ Koh Haa

The Pimpled Phyllidiella has a generally black body colour, with whitish to pinkish to greenish warts (tubercles) and black oral tentacles. The tubercles are usually grouped in clumps. The edge of the mantle is pale pink.

The black body colour forms a net-like pattern, rather than lines which are seen in other similar looking phyllid nudibranchs.

The Pimpled Phyllidiella grows to 6 cm and the body slightly elongate, rather than oval.

This species is highly poisonous.