BIOTIC Species Information for Corbula gibba
|Researched by||Lizzie Tyler||Data supplied by||University of Sheffield|
|Refereed by||This information is not refereed.|
|Scientific name||Corbula gibba||Common name||Basket shell|
|MCS Code||W2157||Recent Synonyms||None|
|Additional Information||No text entered|
|Taxonomy References||Hayward et al., 1996, Hayward & Ryland, 1995b, Tebble, 1976,|
||Feeding method||Passive suspension feeder
Active suspension feeder
|Typical food types||Phytoplankton, diatoms and bacteria.||Habit||Free living|
|Bioturbator||Flexibility||None (< 10 degrees)|
|Height||Insufficient information||Growth Rate||See additional information|
|Adult dispersal potential||100-1000m||Dependency||Independent|
|General Biology Additional Information||Growth
Corbula gibba is a small bivalve mollusc. The growth rate of Corbula gibba is rapid during the first few months of its juvenile stage although it is very slow in adults (Jensen, 1990). In Nissum Bredning, Denmark the growth of juvenile Corbula gibba was rapid during their first two months (July-August) but leveled off in September and October at lengths ranging from 2.9-3.5 mm (Jensen, 1988). Thus juvenile Corbula gibba reached a size of 3 mm within the first 1-2 months after settling (Jensen, 1990). The absolute growth rate for that period was about 0.03 mm/day and remained constant until the end of August. No further growth was observed in September and October (Jensen, 1988). One year after juvenile settlement, specimens reached a mean size of 6 -7 mm. In the Limfjord (Denmark) it was suggested that the variation in growth rates was caused by variable frequencies of wind induced resuspension of settled organic matter. In the Limfjord wind speeds above Beaufort force 8 caused mixing of the water column and probably resuspension of bottom material in 1986. These conditions probably favour Corbula gibba as it is one of the most efficient bivalve particle feeders (Kiøboe & Mohlenberg, 1981). In 1985 the wind speeds never exceeded force 8 and no mixing was observed. This resulted in lower abundances of Corbula gibba and slower growth rates (Jensen, 1990).
Slower growth rates have been recorded in the Danish Sound where it took a population of Corbula gibba seven months to reach a mean size of 1.1 mm (Muss, 1973). Whereas in Port Erin on the Isle of Man it took one year for a population of juveniles to reach a mean size of 4 mm (Jones, 1956, Jensen, 1990). Jones (1956) also reported that the specimens of Corbula gibba on the Isle of Man had a modal length of 2.25 mm. Jensen (1990) suggested that the higher growth rates in the 1990's in Danish waters could be the result of specific events such as eutrophication. However, in Nissum Bredning no specimens were found over two years old in 1990. The size of Corbula gibba around the British Isles ranged from 0.5 mm in length to 1.2 cm in the 1940's (Yonge, 1946), and in Australian waters it can reach sizes up to 1.5 cm (CRIMP, 2000).
Biomass / Production
|Biology References||Jensen, 1990, Rasmussen, 1973, Lauckner, 1983, Jensen, 1988, CRIMP, 2000, Kiørboe & Møhlenberg, 1981, Hrs-Brenko, 1981, Yonge, 1946, Jones, 1956, Yonge & Thompson, 1976, Muus, 1973, Pearson & Rosenberg, 1978, Talman & Keough, 2001, Christensen, 1970, McEnnulty et al., 2001a, NIMPIS, 2002, Healy & Lamprell, 1996, Hayward & Ryland, 1990,|
|Distribution and Habitat|
|Distribution in Britain & Ireland||Common and widespread on all British coasts. The species is probably more widespread than mapped but records are not readily available.|
|Global distribution||Corbula gibba is distributed from the Norwegian Sea south to the Iberian Peninsula, into the Mediterranean and Black Seas, and along the coast of West Africa to Angola.|
|Biogeographic range||Not researched||Depth range|
|Migratory||Non-migratory / Resident|
|Distribution Additional Information||
Preference for coarse muddy sand has also been seen in Port Philip Bay where Corbula gibba are rarely found in sediments that contain less than 10% mud (<63 µm). Below 15% mud there was a strong relationship between the percentage mud and the abundance of Corbula gibba (Parry & Cohen, 2001). Above 15 % mud there was no significant relationship between the abundance of Corbula gibba and percentage mud in the finer sediments (Parry & Cohen, 2001).
Gravel / shingle
|Physiographic preferences||Open coast
Strait / sound
Enclosed coast / Embayment
|Biological zone||Lower Eulittoral
|Wave exposure||Very Exposed
|Tidal stream strength/Water flow||Strong (3-6 kn)
Moderately Strong (1-3 kn)
Weak (<1 kn)
Very Weak (negligible)
|Salinity||Reduced (18-30 psu)
Variable (18-40 psu)
See additional Information
Full (30-40 psu)
|Habitat Preferences Additional Information|
|Distribution References||Hayward et al., 1996, Hayward & Ryland, 1995b, Tebble, 1976, Hrs-Brenko, 1981, Yonge, 1946, McEnnulty et al., 2001b, Jones, 1956, Parry & Cohen, 2001, NIMPIS, 2002, NBN, 2002, JNCC, 1999, Picton & Costello, 1998, Hayward & Ryland, 1990,|
|Reproductive Season||Summer - Autumn||Reproductive Location||Insufficient information|
|Reproductive frequency||Annual protracted||Regeneration potential||No|
|Life span||1-2 years||Age at reproductive maturity|
|Generation time||See additional information||Fecundity|
|Egg/propagule size||Fertilization type||Insufficient information|
|Reproduction Preferences Additional Information||Reproduction
Yonge (1946) determined that Corbula gibba was dioecious with no evidence of a sex change. When the gonads of Corbula gibba are maturing it is easy to distinguish between males and females. Males have white testes whereas females have pink ovaries (Yonge, 1946).
Reproduction and spawning generally occur during summer and autumn. Yonge (1946), observed that during early August the male gonads were filling but were not yet ripe and that the testes had developed further than the ovaries. There were however, no active sperm present. In late August, it was noted that in female Corbula gibba the ovaries were filling. No ripe sperm was found until the middle of September. By the end of September the male and female specimens were ripe. The ripe females had relatively large yolky eggs and ripe males had very active sperm (Yonge, 1946).
Fosshagen, (1965; cited in Muss, 1973) found larvae of Corbula gibba in plankton from October - November and once again from January - February and suggested that it was possible for large individuals to spawn during the autumn.
Larval Settling Time
The settling time of Corbula gibba larvae is variable depending on location and may take several months (Jensen, 1988). In Danish waters settlement occurred in August. (Jensen, 1988) states that the settlement of Corbula gibba is very distinct with very few specimens below 2 mm in size during the month of September in Limjford. The recruitment of Corbula gibba was achieved within one week after settlement (Jensen, 1988). However, high moralities of newly settled individuals occurred during the first month of settling. It was suggested that this was may be due to predation from epibenthic predators. Low and constant mortality occurred during the winter months with decreases in abundance again in spring and early summer. It was suggested that these observation could be due to the weakened conditions in the bivalves that had spawned (Jensen, 1988).
Jensen (1990) suggested that the life span of Corbula gibba seems to be shorter at 1 -2 years in Nissum Bredning than in the first part of this century when individuals had a life span of 5 -6 years with a maximum size of 12 mm (Jensen 1919: cited in Jensen, 1990).
|Reproduction References||Jensen, 1990, Jensen, 1988, Yonge, 1946, Muus, 1973, Eckert, 2003,|