Pseudocnus laevigatus (Verrill 1876) Verrill 1876
- Dataset
- BANZARE holothuroids (Echinodermata: Holothuroidea)
- Rank
- SPECIES
Classification
- kingdom
- Animalia
- phylum
- Echinodermata
- class
- Holothuroidea
- order
- Dendrochirotida
- family
- Cucumariidae
- genus
- Pseudocnus
- species
- Pseudocnus laevigatus
description
Ekman (1927) distinguished a South American form from the Kerguelen form of Cucumaria laevigata and erected Cucumaria perrieri for the former. Panning (1962) considered the distribution of Pseudocnus laevigatus to be Prince Edward, Crozet, Kerguelen and Heard Islands. Some, if not all, of the Prince Edward and Crozet material may prove to be Pseudocnus marionensis (Théel, 1886) (see below). I would add Macquarie I. to Panning’s distribution, but note that there is morphological evidence that Pseudocnus laevigatus on these islands is probably an allopatric species complex. Maximum body length: Heard 44 mm (this work); Kergulen 130 mm (this work; Théel 1886, 115 mm); Macquarie 15 mm (this work; Pawson 1968, 25 mm). Maximum pear shaped ossicle lengths: Heard 128 µ m (this work); Macquarie 144 µ m (this work; Pawson 1968, average 110 µ m); Kerguelen 200 µ m (this work; Théel 1886, 160 µ m). In this work ventral brood pouches were observed in a few Heard I. specimens (NMV F 85005), but not in Kerguelen or Macquarie specimens. The Heard lot of 26 specimens was collected on 28 September from 528 m. Only a few specimens had ventral brood pouches, with eggs and embryos and juveniles at various stages of development. Pawson (1968) did not observe brood pouches in Macquarie specimens.
discussion
Remarks. Pentactella laevigata Verrill, 1876 was described for a single specimen from the Kerguelen Is, and the species later assigned to Pseudocnus Panning, 1949 by Panning (1962). Pawson (1968) discussed a possible “ co-type ” specimen of Pentactella laevigata (USNM cat. No. 3148), but noted that the presence of conspicuous ventral brood pouches that Verrill did not mention, and presence of a calcareous ring that Verrill reported as absent, cast doubt on the type status of this specimen. The largest illustrated ossicle length from the type in Pawson (1968) is 124 µ m, and average length reported as 110 µ m. These are significantly smaller than reported below (160 and 200 µ m) for Kerguelen specimens.
distribution
Distribution. Heard, Kerguelen and Macquarie Islands, littoral to 528 m (Heard I., this work).