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Headshield
snails and slugs
Order Cephalaspidea
updated
May 2020
Where
seen? These odd snails and slugs seen on some of our shores
with seagrasses and mangroves.
What are headshield slugs? Headshield
slugs belong to Phylum Mollusca and Class Gastropoda. They belong to
group of sea slugs (Subclass Opistobranchia)
but most have retained shells as adults, although the shell may be
reduced or internal. There are 31 families of headshield slugs.
Features: Most have shells that are indeed bubble-like; thin and round. While
some have shells large enough to contain the entire animal, in others,
the shell is reduced or internal. All have a well developed headshield,
used to plough beneath the sand. They have no tentacles. Tailed-slugs
of the Family Aglajidae have a long, cylindrical body with a pair
of 'wings' (called parapodia) which fold over the centre of the body
as well as a pair of 'tails, one longer than the other. They have
tiny shells which are internal.
What do they eat? Many bubble
shell snails such as Bulla and Haminoea spp. are herbivores,
placidly munching on filamentous algae.
Some tailed slugs are carnivores and eat their prey whole, crushing
them with hard calcareous plates in the gizzard. Their prey include
other slugs, flatworms, acoel flatworms and polychaete worms.
Some have well developed structures to track down their prey by following
the prey's mucous trail. Others are herbivores.
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Headshield slugs and snails of Singapore |
Order
Cephalaspidea recorded for Singapore
from
Tan Siong Kiat and Henrietta P. M. Woo, 2010 Preliminary Checklist
of The Molluscs of Singapore.
^from WORMS
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Acteon
kirai=^Punctacteon kirai
Pupa nitidula
Pupa solidula
Pupa sulcata |
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Acteocina
capitata
Acteocina singaporensis
Cylichna bizona=^Mnestia bizona
Cylichna cylindracea |
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Family
Aplustridae=Hydatinidae (paper bubble snails) with list of species recorded for Singapore |
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Pyrunculus
sp.
Retusa pelly |
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Ringicula
acuta
Ringicula folini
Ringicula grandinosa
Ringicula propinquans |
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References
- Tan Siong
Kiat and Henrietta P. M. Woo, 2010 Preliminary
Checklist of The Molluscs of Singapore (pdf), Raffles
Museum of Biodiversity Research, National University of Singapore.
- Debelius,
Helmut, 2001. Nudibranchs
and Sea Snails: Indo-Pacific Field Guide IKAN-Unterwasserachiv, Frankfurt. 321 pp.
- Wells, Fred
E. and Clayton W. Bryce. 2000. Slugs
of Western Australia: A guide to the species from the Indian to
West Pacific Oceans.
Western Australian Museum. 184 pp.
- Wee Y.C.
and Peter K. L. Ng. 1994. A First Look at Biodiversity in Singapore.
National Council on the Environment. 163pp.
- Coleman,
Neville. 2008. Nudibranchs
Encyclopedia - Catalogue of Asia/Indo Pacific sea slugs.
Neville Coleman's World of Water, Australia. 415pp.
- Gosliner,
Terrence M., David W. Behrens and Gary C. Williams. 1996. Coral
Reef Animals of the Indo-Pacific: Animal life from Africa to Hawaii
exclusive of the vertebrates Sea Challengers. 314pp.
- Kuiter, Rudie
H and Helmut Debelius. 2009. World
Atlas of Marine Fauna. IKAN-Unterwasserachiv. 723pp.
- Coleman,
Neville. 2008. Nudibranchs
Encyclopedia - Catalogue of Asia/Indo Pacific sea slugs.
Neville Coleman's World of Water, Australia. 415pp.
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Reticulated tailed-slug
