| 1. |
|
|
| 2. |
- Roegner, C., et al.
(författare)
-
Transport of Recently Settled Soft-Shell Clams (Mya Arenaria L.) in Laboratory Flume Flow
- 1995
-
Ingår i: Journal of Experimental Marine Biology and Ecology. - 0022-0981. ; 187:1, s. 13-26
-
Tidskriftsartikel (refereegranskat)abstract
- A laboratory flume was used to examine the retention of juvenile soft-shell clams (2 wk postsettlement) in sediment when exposed to flow. Clams resisted erosion until the initiation of sediment transport, after which they were rapidly advected from sections of test substrate. Comparisons between living and killed clams indicated that burrowing behavior was instrumental for maintaining position in flow I the critical erosion velocity for sediment movement. The ability of low density, shallow-burrowing juvenile bivalves to avoid transport as bedload or resuspended particles is probably minimal during erosional periods, despite that fact that the position of larger, deeper living individuals may be unaffected, In energetic regimes, infaunal recruitment patterns can be dominated by hydrodynamic forces affecting juveniles.
|
|
| 3. |
- Andre, C., et al.
(författare)
-
Fertilization efficiency and gamete viability of a sessile, free-spawning bivalve, Cerastoderma edule
- 1995
-
Ingår i: Ophelia. - : Informa UK Limited. - 0078-5326. ; 43:3, s. 215-227
-
Tidskriftsartikel (refereegranskat)abstract
- The fertilization biology of the free-spawning bivalve Cerastoderma edule was studied in the laboratory. Fertilization success declined drastically with decreasing sperm concentration. Viability of both eggs and sperm decreased with age so that no fertilization took place after 4-8 hours. A dilution model suggests that in the field sperm is rapidly diluted to concentrations that would result in very low fertilization efficiencies. The dilution process thus operates on a much smaller time scale than gamete ageing, indicating that most eggs are fertilized close to spawning males. However, it is also shown that under certain circumstances high concentrations of sperm may accumulate over dense populations of bivalves.
|
|
| 4. |
- Andre, C., et al.
(författare)
-
Species identification of bivalve larvae using random amplified polymorphic DNA (RAPD): differentiation between Cerastoderma edule and C-lamarcki
- 1999
-
Ingår i: Journal of the Marine Biological Association of the United Kingdom. - 0025-3154. ; 79:3, s. 563-565
-
Tidskriftsartikel (refereegranskat)abstract
- The polymerase chain reaction (PCR) was used to produce species-specific DNA markers (RAPDs) from two sibling cockle species and five other co-occurring intertidal bivalves. Amplification reactions with one single primer readily distinguished larvae and adults of Cerastoderma edule from larvae and adults of C. lamarcki, and from adults of Mya arenaria Macoma balthica, Scrobicularia plana, Venerupis pulastra and Mytilus edulis. Random amplified polymorphic DNA (RAPD) is suggested as a simple and quick method to determine species identity in taxa that are difficult to identify on the basis of morphological characters alone, such as marine bivalve larvae.
|
|
| 5. |
|
|
| 6. |
- Lindegarth, Mats, 1965, et al.
(författare)
-
Analysis of the Spatial Variability in Abundance and Age Structure of 2 Infaunal Bivalves, Cerastoderma-Edule and C-Lamarcki, Using Hierarchical Sampling Programs
- 1995
-
Ingår i: Marine Ecology-Progress Series. - 0171-8630. ; 116:1-3, s. 85-97
-
Tidskriftsartikel (refereegranskat)abstract
- Spatial variability in abundance and age distribution of 2 infaunal bivalves, Cerastoderma edule (Linnaeus, 1785) and C. lamarcki (Reeve, 1845), were quantified using hierarchical sampling programs. The scales investigated ranged between 100 and 10(5) m. Analyses of variance revealed significant variability in abundance among sites within bays (similar to 100 m apart) for both species and also among bays (similar to 1 km apart) for C. lamarcki. Mean age varied at several spatial scales. For both species, however, the scale contributing most to the variation was bays, which provided about 40 % of the total variation for each species. Randomization procedures were used to test the generality of previous observations of non-random distributions of year classes (namely number of year classes and dominance by single year classes). These analyses showed that for both species a spatial unit contained significantly fewer year classes and the most abundant year class was significantly more abundant than expected by chance. These results were consistent for all spatial scales except among plots (similar to 10(1) m apart) in C. lamarcki. The necessity to assess spatial patterns at a wide range of spatial scales is emphasized. Potentially important processes (focusing on larval supply and recruitment) which generate the observed patterns and general implications of spatial variability are discussed.
|
|
