The Sarawak pygmy swellshark (''Cephaloscyllium sarawakensis'') is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of catshark, belonging to the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Scyliorhinidae Scyliorhinidae is a Family (biology), family of sharks, one of a few families whose members share the common name catsharks, belonging to the Order (biology), order Carcharhiniformes, the ground sharks. Although they are generally known as cats ...

. It is found in the

benthic zone The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from the Ancient Greek word (), meaning "the depths". ...

near the edge of the Pacific continental shelf, at depths of 118–165 m.

Description

The species reaches a maximum size of 40.8 cm length; males mature at 32.5 cm length and females at 35.4–40.8 cm length. The species uniquely uses sustained single

oviparity Oviparous animals are animals that reproduce by depositing fertilized zygotes outside the body (i.e., by laying or spawning) in metabolically independent incubation organs known as eggs, which nurture the embryo into moving offsprings kno ...

producing larger but fewer eggs than others.

Sustained single oviparity

The mode of

in the Sarawak pygmy swellshark has been found to differ considerably from the two previously defined modes of oviparity found in

Chondrichthyans Chondrichthyes (; ) is a class of jawed fish that contains the cartilaginous fish or chondrichthyans, which all have skeletons primarily composed of cartilage. They can be contrasted with the Osteichthyes or ''bony fish'', which have skeletons ...

. This unique form of oviparity has been described as "sustained single oviparity," a mode of oviparity characterized by the deposition and retention of a single egg case in each

oviduct The oviduct in vertebrates is the passageway from an ovary. In human females, this is more usually known as the fallopian tube. The eggs travel along the oviduct. These eggs will either be fertilized by spermatozoa to become a zygote, or will dege ...

until the two embryos reach a length ranging 16.5–20.1%

total length Fish measurement is the measuring of individual fish and various parts of their anatomies, for data used in many areas of ichthyology, including taxonomy and fishery biology. Overall length Standard length (SL) is the length of a fish measured f ...

References

{{Taxonbar, from=Q4546359 Cephaloscyllium Fish described in 2005