Additions to the Rotatoria of New Zealand—Part VII
[Received by Editor, August 8, 1956.]
The author lists twelve species of the Rotatoria not previously recorded in New Zealand, most of them from the Wainuiomata River, Wellington. One rare species is recorded from Otago. It is suggested that some rotifers which have been described as forms or varieties of a species may be merely mictic and amictic females.
This paper lists twelve species of the Rotatoria not previously recorded in New Zealand. Most of the specimens were collected from the Wainuiomata River, Wellington, and these are all littoral rotifers. One species of the genus Conochioides found at Dunedin is of special interest; first described from Russia, it has been sparingly recorded in America and very few other countries. It has now appeared in a pond on Saddle Hill, Dunedin.
In many collections of the Rotatoria will be found specimens having the main characteristics of one species but differing in size and other small particulars: these have often been described as varieties or forms. From a preliminary study of these animals, Russell (1955), it is considered that these may be merely mictic and amictic females, and in one case this has been shown to be the case.
In the systematic list species have been placed in alphabetical order for ease of reference; and to save space short titles only have been given. For the older references Harring (1913) gives full titles and synonymies.
Aspelta aper (Harring)
1913. Encentrum aper Harring. Proc. U.S. Nat. Mues., Vol. 46, p. 394.
Locality. Wainuiomata River. Wellington; above Marton Dam. Length of body, 300 microns; of toes, 44 microns, of trophi, 48 microns. All the specimens were smaller than those found in America. Not common.
Conochiloides coenobasis Skorikov 1914.
Arbeiten ichtyolog. lab. Kaspi-Wolg. Fisch.-Ver. Astrachan, 3(5): 30, Figs. 1, 2.
Locality. Pond on Saddle Hill, Dunedin. Total length, 160 microns. Ventral antenna prominent. Common.
Cephalodella pheloma Myers 1924.
Rotifer Fauna Wisconsin pt. 2. Wis. Acad. Sci. Art. Lett. Vol. XXI, pp. 496–7.
Locality. Wainuiomata River, Wellington; above Marton Dam. This is a variety and has a number of differences from the type. The toes are longer and recurved, and the head less oblique. In other characteristics, particularly the highly compressed neck, and long foot glands, the animal is normal for the type. Not common. Total length, 150 microns. Length of body, 80 microns; of head, 30 microns; of toes, 40 microns.
Cephalodella plicata Myers 1924.
Rotifer Fauna Wisconsin pt. 2. Wis. Acad. Sci. Art. Lett. Vol. XXI, p. 483.
Locality. Wainuiomata River, Wellington; above Marton Dam. Specimens were all smaller than those described from America, and symbiotic zoochlorellae were absent. The deep dorsal and lateral clefts, and lack of projecting lips, distinguish it from C. hoodi, and C. ventripes. Length of body, 70 microns; of toes, 14 microns. Not common.
Dapidia pyriformis (Gosse)
1851. Euchlanis pyriformis Gosse. Ann. Mag. Nat. Hist; ser. 2, Vol. 8, p. 201.
Locality. Victoria Lake, Christchurch. Temperature 65° C., pH 6.5. All the specimens examined were very large and with the posterior edge of the plate slightly emarginated. The salivary glands were prominent. Total length of body, 380–410 microns. Length of toes, 110–130 microns. Fairly common.
Lecane inopinata Harring and Myers 1926.
Rotifer Fauna Wisconsin pt. 3. Wis. Acad. Sci. Art. Lett., Vol. 22, pp. 374–5.
Locality. Pond on Saddle Hill, Dunedin. The principal difference from the type is that the toes are fused together for more than half their length. Length of body, 80 microns. Length of toes and claws, 23 microns. Width of anterior points, 48 microns. Moderately common.
Lecane verecunda Harring and Myers 1926.
Rotifer Fauna Wisconsin pt. 3. Wis. Acad. Sci. Art. Lett. Vol. 22, pp. 358–9.
Locality. Wainuiomata River, Wellington, above the Marton Dam. No facetting was found on the dorsal plate of specimens, although the usual markings were evident on the ventral plate. The first foot joint was ovate and more prominent than in the type. The second foot joint did not extend past the posterior segment. It is considered that the specimens are a variety of the type, and that the differences do not warrant describing them as forms. Length of dorsal plate, 70 microns; of ventral plate, 76 microns. Width of dorsal plate, 56 microns; of ventral plate, 48 microns. Width of anterior points, 50 microns. Length of toes, 24 microns. Not common.
? Lindia torulosa Dujardin 1841.
Hist. Nat. Zooph. p. 653.
Locality. Wainuiomata River, Wellington, above Marton Dam. The specimens were all considerably smaller than found in France and America. The principal difference found was in the trophi; the unci appeared to have only two teeth united by a lamella, the plate having a sigmoid curve and with 8–10 fine ribs. The epipharynx was entirely different from the type and consisted of two club-shaped members. The trophi could not be resolved without dissolving the body with sodium hypochlorite, but this also attacked some parts of the trophi which were not hardened. In view of Harring and Myers' (1922) suggestions the specimens are tentatively referred to L. torulosa, to which they bear considerable likeness both in body form and in the general shape of the trophi. Fairly common.
Lindia euchromatica Edmondson 1938.
Trans. Amer. Micr. Soc., Vol. LVII, No. 2, pp. 154–7.
Locality. Wainuiomata River, Wellington; above Marton Dam. Specimens were smaller than those described by Edmondson. The differences in the trophi are that the rami in ventral view are considerably wider; the sickle shaped expansion to the manubria is smaller, and the hammer-shaped head of the epipharynx is less pronounced. It was also found that a few of the specimens had the arms of the epipharynx almost straight rather than spindle shaped. Average length of specimens 100–150 microns. The length of the toes is from 5–10 microns. Fairly common.
Monommata caeca Myers 1930.
Rotifer Fauna Wisconsin pt. 5. Wis. Acad. Sci. Art. Lett. Vol. 25, pp. 391–2.
Locality. Wainuiomata River, Wellington; above Marton Dam. Typical specimens except for differences in size and slight modifications of the trophi. The manubria are slightly longer and have a greater curvature than American specimens. Length of body, 68 microns. Length of right toe, 140 microns; of left toe, 106 microns. Length of trophi, 24 microns. Rare.
Proales sordida Gosse 1886.
The Rotifera, Vol. 2, p. 37, Pl. 18. Fig. 6.
Locality. Wainuiomata River, Wellington; above Marton Dam. Typical specimens. Length of body, 194 microns; length of toes, 10 microns. Fairly common. Gosse's description is not very complete, but in conjunction with his figures there is little room for doubt as to the animal he named. Moderately common.
Trichocerca cavia (Gosse)
1886. Coelopus cavia Gosse. The Rotifera, Vol. 2, p. 69, Pl. 20, Fig. 22.
Locality. Wainuiomata River, Wellington; above Marton Dam. Typical specimens, but larger than most European forms. Total length, 104–110 microns. Rare.
A majority of the specimens listed in this paper came from the Wainuiomata River, and were collected by Miss B. A. Holloway, of the Dominion Museum, to whom I extend my thanks. I have also to thank Miss Jean Thomson, of Otago University, for collecting the Saddle Hill specimens. Lastly, I must thank Professor E. Percival, of Canterbury University College, and Dr. R. R. Forster, of the Canterbury Museum, for the assistance they have given me during the last year when difficult problems have arisen.
Harring, H. K., 1913. Synopsis of the Rotatoria. Bull. 81, Smithsonian Institute, Washington.
Harring, H. K. and Myers, F. J., 1922. The Rotifer Fauna of Wisconsin, Part 1. Wis. Acad. Sci. Art. Lett., Vol. XX, p. 619–20.
Russell, C. R., 1955. Some Rotifers from the Fiordland District. Canterbury Museum Records, Vol. 7, No. 1.
C. R. Russell,M.Sc. (Eng.), F.R.M.S.,
108 Knowles Street, Christchurch.