BULLIDAE
bubble shells

  Bulla ampulla
Linnaeus, 1758

Relevant Synonyms
Bullaria ampulla (Linnaeus, 1758)

Misidentification
-

 photo: E. Vardala-Theodorou    

SHORT DESCRIPTION
Shell large, globose, involute with sunken spire, smooth and polished, with very fine growth lines. Aperture which occupies the whole shell length and widens anteriorly, with outer lip uniformly curved; thickened anterior part of outer lip continuous with columella, and hence with callus on parietal wall. The soft parts can withdraw completely into the shell. Head shield large, with small eyes and four small lobes.

color : varies from tan or pinkish to brown and greenish grey, closely and finely mottled or speckled all over with pinkish-grey, usually with darker blotches, irregular or V shaped; occasionally with two broad indistinct bands on body whorl; interior and parietal callus are white; fresh shells covered with a thin yellowish periostracum; soft parts vary from light cream to orange.

common size : shell rather large for the family, measuring 40-60 mm.

DISTINGUISHING CHARACTERISTICS
The common Mediterranean species, B. striata Bruguière, 1792, is smaller, more slender with a greenish-grey ground color. There is a very similar Atlantic species, B. amygdala Bruguière, 1792, which has occasionally been reported from the Canary islands, but not in the Mediterranean. The records of B. ampulla in the eastern Atlantic are misidentified with B. amygdala.

BIOLOGY / ECOLOGY
Herbivorous and nocturnal as other species of this genus, it feeds mainly on small seaweeds; can be found enclosed in a cocoon of mucus and sandgrains (Kilburn and Rippey, 1982). The spawn is a long, bright yellow to orange, tangled string of jelly, containing a continuous string of tiny oval capsules. Each one contains 1-25 eggs, which develop into free-swimming veliger larvae.

habitat : not seen alive in the Mediterranean, where only few empty shells have been found. This species lives intertidally or in shallow water, mainly in sandy mud with seagrass; in Cyprus at 9 m depth.


1st Mediterranean record
Israel, 1982 [1978].


DISTRIBUTION
Worldwide: widespread throughout the tropical Indo-Pacific. Mediterranean: recorded first in 1978 from Tel Aviv, Israel (Barash and Danin, 1982b); successive records from Greece, Elefsis Bay (Vardala-Theodorou, 1999; also seen in Turkey (van Aartsen, pers. comm.) and Cyprus (J. Varnavas, pers. comm., sighted August 2000).

ESTABLISHMENT SUCCESS
Rare in the Levantine Sea where only few empty shells have been found; not uncommon in Elefsis Bay, Aegean Sea.

speculated reasons for success :
-


MODE OF INTRODUCTION
Possibly via the Suez Canal.


IMPORTANCE TO HUMANS
None.


KEY REFERENCES

  • Barash A. and Danin Z., 1982b. Mediterranean Mollusca of Israel and Sinai: composition and distribution. Israel Journal of Zoology, 31: 86-118.
  • Kilburn, R. and Rippey, E., 1982. Sea Shells of Southern Africa. Macmillan South Africa, Johannesburg, 249 p.
  • Vardala-Theodorou, G.E., 1999. The occurrence of the Indo-Pacific molluscan species Fulvia fragilis (Forsskal, 1775) and Bulla ampulla L., 1758 in Elefsis Bay. Newsletter of the Hellenic Zoological Society, February, 1999, Fasc. 31: 10-11.

 

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Last update : December 2003

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