Capitella teleta

Capitella teleta is a small, cosmopolitan, segmented annelid worm. It is a well-studied invertebrate, which has been cultured for use in laboratories for over 30 years. C. teleta is the first marine polychaete to have its genome sequenced. For many years researchers believed that Capitella capitata was the only representative of this genus that survived, and flourished, in polluted environments. After the oil spill that occurred near Cape Cod in West Falmouth, Massachusetts in 1969, researchers collected sediment and found an abundance of what they believed to be C. capitata. However, subsequent research showed that while the individuals collected from that region had very similar gross morphology, their life histories, methods of reproduction and genetics indicated there were at least six distinct species. Capitella species 1, eventually described as C. teleta in 2009, was one of the initial species identified from these surveys. After 30 years of research on the group, Capitella teleta was officially described in 2009 by Blake et al. The species name is derived from the Greek word teleta, meaning 'initiation'. This word symbolizes that it was the first alternative Capitella species that was identified. This organism is commonly found in sediments along the east and west coasts of North America. Additional reports have placed this group in the Mediterranean region as well as Japan. Capitella teleta lives in shallow-water or in the intertidal. Capitellids are commonly thought of as opportunistic in nature, due to their ability to inhabit and flourish in organically enriched marine sediments. C. teleta has a narrow, segmented body with sexually modified setae. This group exhibits sexual dimorphism and females setigers 8-9 have hooded hooks in the podia while males have genital spines on setigers 8-9. Generally, there are separate sexes, however, hermaphroditism is possible when there are low densities of females. Males, females and hermaphrodites are of similar size (max size collected was a male that is 24 mm in length). Initial embryogenesis of C. teleta is similar to spiralian development. Developmental studies have found that C. teleta is a semi-direct developer with a reduced segmented, non-feeding, pelagic larval stage. Metamorphosis into the juvenile state involves a transition in habitat (pelagic to benthic) and the beginning of feeding behavior with few morphological changes outside of an elongated body form. In her 2016 review, Seaver notes the paradox of the conserved pattern of early development among molluscs, platyhelminthes, annelids and some nemerteans due to the enormous diversity of adult and larval body forms. Many annelids possess the capability to regenerate their anterior, posterior, or both ends of their body. The posterior portion of C. teleta is capable of regenerating if sliced perpendicular to their sagittal axis. Recent research found the capability of posterior regeneration in C. teleta is controlled by epimorphosis and several key Hox genes over a period of two weeks.