Marbled Crayfish Breeding Guide
The marbled crayfish (Procambarus virginalis) reproduces by parthenogenesis: all-female clones, no mating, plus a critical invasive-release warning.
Overview
The marbled crayfish (Procambarus virginalis, Marmorkrebs) is remarkable for being an all-female species that reproduces by parthenogenesis: every individual is female, and the offspring are genetically identical to the parent. It is an extremely young species, and all marbled crayfish are thought to be the clonal descendants of a single specimen dating to approximately 1988. The animal is triploid, carrying 276 chromosomes; the leading hypothesis is that an error in meiosis produced a diploid gamete which, once fertilised, created a viable triploid individual.
Reproduction Without Mating
Because reproduction is parthenogenetic, no male is required and there is no courtship or sexing to perform: a single isolated animal can establish an entire population. Each individual lays eggs that develop into clonal female young, and the generation time is on the order of several months. The recorded aquarium tolerance for the species is 18-25 C, pH 6.5-8.0 and a general hardness of 5-20 dGH, with low flow. Adults reach roughly 8-13 cm.
- Reproduction: parthenogenesis (all-female, clonal)
- Temperature: 18-25 C (64-77 F)
- pH: 6.5-8.0
- GH: 5-20 dGH
- Generation time: several months
- Adult size: 8-13 cm
Juveniles
The female carries her eggs and then the hatched juveniles beneath the abdomen until they are developed enough to live independently. Because a single clutch can be large and the young are themselves immediately capable of clonal reproduction, populations expand very rapidly under favourable conditions.