The Holothurian Fauna of Cook Strait, New Zealand
Kolostoneura Becher, 1909
Kolostoneura Becher, 1909
Diagnosis: Calcareous deposits absent from the body wall. Tentacles ten. General features of anatomy similar to those in Trochodota Ludwig.
Type Species: Kolostoneura novae-zealandiae (Dendy and Hindle).
The genus Kolostoneura is monotypic, and Dendy and Hindle (1907) originally placed the species in genus Rhabdomolgus. Becher (1909) proposed a new genus for the New Zealand species to eliminate any suggestion of a genetic relationship with Rhabdomolgus ruber Keferstein, which is known from deeper waters in the Northern Hemisphere. Clark (1921) fully agreed with Becher's decision, and stated that Kolostoneura was probably derived from Trochodota by loss of (1) wheels and (2) sigmoid hooks. Mortensen's (1925) discovery of sigmoid hooks in some specimens from Plimmerton infected by ectoparasitic snails lends support to Clark's thesis.
Kolostoneura forms a parallel to Anapta Semper, which is described as a Leptosynapta Verrill without deposits in the skin, and Achiridota Clark, which is a Chiridota Eschscholtz without deposits (Clark, 1921).
Kolostoneura novae-zealandiae (Dendy and Hindle)
- Rhabdomolgus novae-zealandiae Dendy and Hindle, 1907, p. 113. Pl. 11, figs. 1–4; Pl. 13, figs. 16–17; Pl. 14, figs. 22–29.
- Kolostoneura novae-zealandiae Becher, 1909, p. 35; Clark, 1921, p. 164; Mortensen, 1925, p. 383; Dawbin, 1950, p. 40.
Material Examined: Island Bay, intertidal rock pools, 11 specimens, collected by A. D. Allen and D. L. Pawson. 15/7/1959; Napier, muddy tide pool, 3 specimens, collected by D. L. Pawson, 20/5/1959.
Diagnosis: Colour in life pinkish brown to white transparent. White and transparent in alcohol. Tentacles pinnate, occasionally containing calcareous deposits.
Description: Small holothurians, approximately cylindrical in shape, white transparent in alcohol. The radial longitudinal muscles can be clearly seen through the skin. Total length varies between 15mm and 40mm. Each of the ten tentacles gives rise to five pairs of pinnately arranged digits, which increase in length toward the distal extremities of the tentacles.
Dendy and Hindle (1907) gave a very thorough description of the internal anatomy of this species. Mortensen (1925) added that he almost invariably found calcareous deposits in the tentacles.
Distribution: Dendy and Hindle's (1907) specimens were taken from New Brighton Beach, Kaikoura, and Owenga in the Chatham Islands. Mortensen (1925) found specimens at Akaroa, Plimmerton, Takapuna Beach and Stewart Island. The new locality, Napier, leads to the suggestion that K. novae-zealandiae may prove to be present around the entire New Zealand coast. The species is endemic to the New Zealand region.
Ecology: This species has only been taken from the intertidal zone, where it lies concealed under rocks in mud or sand.
Discussion: Examination of the tentacles of all the specimens on hand showed that only two were found to possess calcareous deposits in the tentacles.
K. novae-zealandiae appears to have no near relatives in New Zealand or overseas.