Summary
Physical Description
Ecology
Life History & Behaviour
Anatomy & Physiology
Evolution & Systematics
Biogeographic Distribution
Conservation & Threats
References & Links | Life History & Behaviour
Pyura sp is hermaphroditic, having one ovary and testis present on each side of the body (Kott, 2005). Fertilization takes place externally with eggs and sperm released into the water column via the atrial siphon (Ruppert et al., 2004). Very little is known about the timing of gamete release in ascidians. Pyura stolonifera has been found to synchronously release gametes, however only a subsection of the population releases gametes in a spawning event with several synchronous spawning events in each population (Marshall, 2002). It is likely that this species of Pyura has a similar reproductive behaviour and synchronously releases gametes. After fertilization takes place, the embryo develops and hatches into a tadpole larva (Kott, 1989). The tadpole larva is free swimming and is the main dispersal stage however only lasts a few days as it doesn’t feed. The larva then finds a suitable substrate for attachment, settles, and undergoes metamorphosis into the sessile adult (Kott, 1989).
As a sessile organism the behaviours of this species of ascidian are limited to feeding and reproduction. Ascidians are able to selectively feed by opening and closing their siphons (Kott, 1989). In response to sedimentation, pretators or other disturbances they are also able to squirt out up to 1/3 of the water in their body cavity (Kott, 1989). For more information on feeding see anatomy and physiology.
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