Data about Bivalvia

TraitBank assembles data records from many providers. Select a row for more details about the record, or search within Bivalvia.

Physical Description

Data about Bivalvia
  • sexual dimorphism
    Sexual dimorphism is a phenotypic difference between males and females of the same species. The prototypical example is for differences in characteristics of reproductive organs. Other possible examples are for secondary sex characteristics, body size and morphology, ornamentation and behavior.
sexual dimorphism
Additional detail dwarf males Fairbairn, 2013  
Additional detail female larger Fairbairn, 2013  
Additional detail sexes shaped differently Fairbairn, 2013  

Life History and Behavior

Data about Bivalvia
Additional detail dioecious
  • dioecious
    Dioecy (Greek: "two households"; adjective form: dioecious) is characterised by a species having distinct male and female organisms.
Fairbairn, 2013  
Additional detail sequential hermaphrodite
  • sequential hermaphrodite
    Some members of this lineage are sequential hermaphrodites; they are born as one sex, but can later change into the opposite sex.
Fairbairn, 2013  
Additional detail simultaneous hermaphrodite
  • simultaneous hermaphrodite
    Some members of this lineage are simultaneous hermaphrodites; a condition of hermaphroditic animals (and plants) in which the reproductive organs of both sexes are present and functional at the same time.
Fairbairn, 2013  


Data about Bivalvia
percent species currently described
Additional detail 64 Appeltans et al, 2012  
percent synonyms
Additional detail 55 Appeltans et al, 2012  
described (accepted)
Additional detail 9,000 Appeltans et al, 2012  
total unknown species (expert opinion)
Additional detail 5,000 Appeltans et al, 2012  
undescribed species present in museum collections
Additional detail 2,000 Appeltans et al, 2012  
undiscovered morphospecies (not yet collected)
Additional detail 3,000 Appeltans et al, 2012  
percent surveyed species not yet known to science
Additional detail 0.31 Appeltans et al, 2012  


EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.

To request an improvement, please leave a comment on the page. Thank you!