Sacculina carcini Thompson, 1836.
Body of grownup females is manufactured from tissue and is roofed with a skinny cuticle devoid of calcareous plates, traces of segmentation, distinct areas, appendages, or an alimentary tract. The physique consists of a central nucleus, which attaches itself onto the mid-gut of the host from the place it sends root-like appendages (the interna) into each a part of the host’s physique. This nucleus connects to the outside of the host with the exterior knob sac (the externa). Males are dwarves, microscopic cyprids that connect to females.
Occurs in European seas; predator of the inexperienced crab, Carcinus maenas and different crabs.
Uses its root-like extensions to connect to the host’s visceral organs, nervous system, gonads, and appendages, however don't penetrate contained in the host.
A bunch’s gonads are castrated by this parasite; in grownup males, the stomach turns into feminized. Young crabs don't type gonads when infested.
FEEDING ECOLOGY AND DIET
Nourishment is completed by diffusing nutritive substances from host’s blood. It could assault organs with enzymes it secretes. Males obtain nourishment from the feminine’s physique.
External sac has branched ovaries and a pair of male sperm receptacles. A male cyprid swims into the feminine’s physique. After attachment, male extrudes its complete cell content material into the feminine. Male takes up residence and its perform is to produce sperm. Fertilization and brooding happen within the externa; nauplii hatch out of the eggs, move by means of 4 naupliar levels. One parasite can release many broods throughout one season, however the peak of replica is throughout summer time; there's a relaxation interval within the winter. The interval of incubation is 12–35 days; after 10 days the parasite settles. Female cyprids connect to the bottom of their host’s bristles. Females abandon their limbs, thorax, mantle, and carapace, and develop a curved stylet by means of which their cells move into the host’s physique. After an inside section, which may final up to three years, females produce an externa, attracting male cyprids.
Not listed by the IUCN.
SIGNIFICANCE TO HUMANS
Suggested as a organic management agent towards the invasive inexperienced crab, Carcinus maenas, which is negatively affecting coastal ecosystems worldwide.