Bispira variegata Breeding Guide

How the cluster duster Bispira variegata reproduces sexually by broadcast spawning and asexually by architomy; WoRMS treats variegata as a synonym of B. melanostigma.

Overview

Bispira variegata is a small cluster-forming feather duster of the family Sabellidae. In the World Register of Marine Species the name Bispira variegata is listed as unaccepted, with the currently accepted name Bispira melanostigma (Schmarda, 1861), so its biology is read together with the genus and its close relative the social feather duster Bispira brunnea. Members of Bispira filter plankton with a crown of banded radioles and tend to live in tight groups of many individuals.

Reproductive Mode

Within the genus, both sexual and asexual reproduction occur within a population at the same time. In the well-studied Bispira brunnea, the great majority of individuals reproduce sexually (as gonochores or hermaphrodites), with sequential protandrous hermaphroditism suggested.

Asexual Reproduction

Bispira also reproduces asexually by architomy, in which buds are produced inside the parental tube at several regenerative stages. In B. brunnea a substantial fraction of the population was found reproducing by architomy, which underlies the dense clusters characteristic of these worms.

Sexual Reproduction

As in other sabellids, sexual reproduction proceeds by external fertilisation after gametes are released into the water, followed by a planktonic larval phase before settlement and growth into adult worms.

Common Challenges

In an aquarium, increase comes mainly from asexual budding within the cluster rather than from larval rearing, which is impractical. Adequate suspended plankton is essential, and crowns may be shed under stress and later regenerated.