BIOTIC

BIOTIC Species Information for Aphrodita aculeata

Researched by

Lizzie Tyler

Data supplied by

University of Sheffield

Refereed by

This information is not refereed.

Reproduction/Life History

Reproductive type

Gonochoristic

Developmental mechanism

Lecithotrophic

Reproductive Season

winter - spring

Reproductive Location

Water column

Reproductive frequency

Annual episodic

Regeneration potential

Life span

6-10 years

Age at reproductive maturity

1-2 years

Generation time

Insufficient information

Fecundity

Egg/propagule size

Fertilization type

External

Larvae/Juveniles
Larval/Juvenile dispersal potential	Insufficient information	Larval settlement period	Insufficient information
Duration of larval stage

Reproduction Preferences Additional Information

Little information on the reproduction and development of this species was found.
Gametogenesis
Aphrodita aculeata is dioecious, i.e. has separate sexes. In females, the ova (eggs), and in males the sperm, develop from the peritoneal sheath of the blood vessels (except the major dorsal and ventral vessels and branches close to the intestine) (Fordham, 1925). The ova and sperm are released into the body cavity (coelum) where the sperm complete their development. Mature females can be identified by 'cream coloured' eggs visible through the thin walls of the parapodia. In mature males the coelum is filled with a milky fluid, i.e. sperm (Fordham, 1925). No spermatophore was observed, although sperm may be arranged in groups of up to four (Fordham, 1925). Presumably large numbers of eggs and sperm are released although no estimate of fecundity was found.
Spawning
Sperm and ova are shed through the nephridia (the annelid excretory organs) and their nephridiopores on the dorsal surface (Fordham, 1925). Mature males and females were observed at Plymouth in October, when males were seen to spawn, although mature specimens were also collected in March (Fordham, 1925). Fordham (1925) also reported mature individuals in May and spawning in June (location unknown), and mature females in the Naples area in September. Individuals were observed spawning off Rame, Plymouth in November 1923 and mature females were collected in the Plymouth area in September 1930 (MBA, 1957). Thorson (1946) reports spawning in the Naples area in January and February, in aquaria in Naples in March, and mature females in the St Andrews area in May. Overall, Thorson (1946) suggested that spawning occurred in winter and spring.
Larval development
Larval development is probably but not necessarily similar to related species of Aphroditidae such as Hermonia hystrix and to a lesser degree to members of the Polynoidae such as Harmothoe lunulata (as imbricata). Larval development is lecithotrophic in the Aphroditidae so far studied i.e. Hermonia hystrix (Rouse & Pleijel, 2001). The larva is probably a ciliated, free-swimming trochophore, which develops into a juvenile composed of only a few segments on settlement. The larvae of Hermonia hystrix has a long pelagic phase (von Draschke, 1885 cited in Thorson, 1946). However, although Aphrodite aculeata were very common in the Øresund and, therefore, their larvae were expected to be common in the plankton, none were found in a four year period (Thorson, 1946). Therefore, Thorson (1946) suggested that the larvae of Aphrodite aculeata either had a very short pelagic phase or non-pelagic development. However, no information on the larval development of this species was found.

Reproduction References

Fordham, 1925, Thorson, 1946, Schroeder, 1989, Rouse & Pleijel, 2001, MBA, 1957, Schroeder & Hermans, 1975, Julie Bremner, unpub data,