Additions to the Rotatoria of New Zealand. Part III

Transactions and Proceedings of the Royal Society of New Zealand, Volume 78, 1950, Page 161

Additions to the Rotatoria of New Zealand. Part III By C. R. Russell [Read before the Canterbury Branch, April 7, 1948; received by the Editor, April 19, 1948.] Introduction This paper contains a list of eighteen species of the Rotatoria not previously recorded in New Zealand, and includes one new species. Most of the rotifers listed are lacustrine forms from the mountainous lakes of the South Island, and were found in plankton samples collected by Professor E. Percival, of Canterbury University College. Two interesting species of the genus Pedalia were found whose distribution is confined, except in rare instances, to high altitude lakes in a comparatively few countries. The genus is important as it shows the extreme development in the appendages of the family Filiniidae. In this paper the two genera Lecane and Monostyla have been retained, although there is a perfect transition between the two, and apparently no homonyms; but as Ahlstrom (1938) has stated, there are over one hundred species in Lecane and at least fifty in Monostyla, so that combining these genera increases taxonomic difficulties and obscures the relationships. It might be added that some species have been differentiated on such minor morphological points that it is now difficult to separate one species from another, and it is only with the greatest difficulty that material can be assigned to a described species. In the systematic list forming the body of this paper synonyms have been reduced to a minimum, and only the short titles given to the literature cited. In the case of descriptions of species, besides the original citation references have when possible been given to literature available in New Zealand. Since 1925 many of the descriptions of new rotifers have been given in museum bulletins and in special papers, rather than in the journals of the larger scientific societies. This has resulted in fewer descriptions being available in the libraries of this country. The rotifers so far found in New Zealand are listed in the following papers: Russell, “A New Rotifer from New Zealand,” Jour. Royal Microscopical Soc., 1944, vol. 64, pp. 121–123.; Russell, “A Reference List of the Rotatoria of New Zealand with Ecological Notes,” Trans. Roy. Soc. N.Z., vol. 75, pp. 102–123; Russell, “Additions to the Rotatoria of N.Z., Part 1,” Trans. Roy. Soc. N.Z., vol. 76, pp. 403–408; Russell, “Additions to the Rotatoria of N.Z., Part 2,” Trans. Roy. Soc. N.Z., vol. 77, pp. 351–4. At the present time more than 1,200 species of the Rotatoria have been described and of these approximately one-third have been found in New Zealand. In the present paper, specimens found in Professor Percival's samples have been marked (P.) under the heading Locality.

Notommatidae Cephalodella megalocephala (Glascott) 1893. Furcularia megalocephala Glascott. Sci. Proc. R. Dublin Soc., vol. 8, p. 56. 1924. Harring and Myers, pp. 494–6. Locality. Small pond, Hagley Park, Christchurch. Fairly common. Temp. 15°C., pH 8. Length of body 190μ, toes 35μ. Neck is more strongly marked than in European specimens and the manubria more robust. Cephalodella panarista Myers. 1924 1924. Myers, Trans. Wis. Acad. Sci., Arts, Lett., vol. 23, pp. 478–9, pl. 31, figs. 5–7. Locality. Lake Tekapo. Length 240μ, toes 60μ, a spicule is present in most cases. (P.) Proales parasita Ehrenberg 1838. Notommata parasita Ehrenberg. Infusionth, p. 426, pl. 50, fig. I. 1920. Harring and Myers, p. 607. Locality. Small pond, Hagley Park, Christchurch. Temp. 15°C., pH 8. Length 162μ, toes 12μ; rare. This animal was found free swimming, although parasitic in Volvox in Europe and America. The animal described by Hudson and Gosse as P. parasita is Ascomorpha volvocicola (Plate) as pointed out by Rousselet and Harring and Myers. A. volvocicola was found free swimming (Russell, 1945, p. 114), but has lately been found in Volvox colonies in Lake Tekapo. Probably a further search will show P. parasita to be both free and parasitic. Both species are well adapted for a free existence. Lindia pallida Harring and Myers. 1922 1922. Harring and Myers, Trans. Wis. Acad. Sci., Arts, Lett., vol. 20, p. 607. Locality. Pond, Hagley Park, Christchurch. Temp. 10°C., pH8. Length 270μ. Not common. Brachionidae Brachionus caudatus var. aculeatus (Hauer) 1937. Brachionus angularis var. aculeatus Hauer. Nue Rotatorien aus Indien. III. Zool. Anz., vol. 120, pp. 17–19. 1940. Ahlstrom, p. 159. Locality. Pools, Kapiti Island; pH 10. Length lorica 162μ, maximum width 127μ. The auxiliary spines were very pronounced. This animal was collected by Mr. P. Malone, of Victoria University College. Keratella quadrata var. edmondsi Ashlstrom. 1943. 1943. A Revision of the Rotatorian Genus Keratella. Bull. Amer. Mus. Nat. Hist., vol. 80, art. 12, p. 447, pl. 41, fig. 4. Locality. Lake Lyndon. Length overall 220μ, width 100μ. The lateral plaques on some specimens were not complete, and the left posterior spine almost obsolete. Keratella carinata n.sp. Text-figs. 1 and 2 The lorica terminates in a short, stout, recurved spine which is slightly off the median line. The maximum width of the lorica is approximately seven-tenths of its length, and occurs slightly before mid-length. The depth of the lorica is approximately five-elevenths of its length, and is almost constant for three-quarters of its length when it falls sharply to the posterior spine. (Text-fig. 1.)

Fig. 1—Keratella carinata. Lateral view. (Right anterior spines omitted) There are six anterior spines. The medians are slightly diverging, and at approximately one-quarter their length are bent ventrally 90°. The length of the medians is appoximately seven-tenths of the lorica. The intermediate spines are slightly diverging, straight, and inclined to the ventral at 45°. The lateral spines proceed from the anterior lateral edge of the lorica normal to the ventral surface. In a few specimens the laterals were slightly inclined posteriorly. Fig. 2—Keratella carinata. Dorsal view The pattern of the dorsal plate is very irregular. There are two closed anterior plaques, a hexagon and a pentagon, followed by two pentagons, a hexagon, and a pentagon, arranged in an approximate semi-circle. Posterior to these are a pentagon, and two hexagons. Two open plaques complete the pattern. (Text-fig. 2.) The dorsal plate is areolated except in the central area, the markings being minute. The dorsal pattern, although unsymmetrical, is constant between specimens except that the sides of the plaques on the extreme edge of the lorica are sometimes missing. The main features of this species are: the dorsal pattern, the depth and shape of the lorica with its almost vertical sides, and the length, inclination, and shape of the anterior spines. K. carinata

resembles K. irregularis and K. mixta, but only superficially. It resembles the latter from a dorsal view, but the posterior spine is not so much off the median line and the lateral spines of K. mixta are entirely different. The median and intermediate spines of K. carinata are longer and more acutely bent. The similarity with K. irregularis is confined to the dorsal view, the anterior spines of the latter are different in length and position, and the posterior spine is decurved instead of being recurved. The dorsal pattern of K. carinata is entirely different from that of any other species. As Ahlstrom (1943) has stated, “The foundation pattern of the dorsum is constant in any species, and is a highly important taxonomic character.” The internal organs of K. carinata are normal to the genus. Twelve specimens examined had the following range of measurements: Length over all 125–140μ Depth 50–60 Width 65–75 Anterior spines: Median 70–80 Intermediate 15–22 Lateral 20–25 Posterior spine 10–20 Locality. K. carinata was collected by Professor Percival from peaty roadside pools at Kumara, Westland. From the nature of the material it is assumed that the water was of acid content. It was also taken by Mr P. J. Parr in high-level acid pools on the Maungatua Range and on Swampy Hill, Otago. At the latter locality the temperature was 7° and the pH 4. A type specimen is deposited with the Canterbury Museum, Christchurch. Euchlanidae Euchlanis dilitata var. crassa Myers. 1938 1938. Myers, Amer. Mus. Novitates, no. 1011, p. 14. Locality. Lake McGregor, Canterbury. Length of lorica 200μ, width 170μ, depth 130–140μ. Not common. (P.) Lecane leontina (Turner) 1892. Cathypna leontina Turner. Bull. Denison Univ., vol. 6, p. 61, pl. 1, fig. 12. 1926. Harring and Myers, p. 326. Locality. Lake Tekapo, Canterbury. Length of plate 138μ. width 83μ, toes 31μ, spicules long. Not common. (P.) Lecane styrax Harring and Myers. 1926 1926. Harring and Myers, pp. 389–90. Locality. Peaty roadside pools near Kumara, Westland. Length 123μ, maximum width 85μ, toes, less claw, 50μ, claw 20μ Rare. (P.) Lecane ploenensis (Voigt) 1902. Distyla ploenensis Voigt. Zool. Anz., vol. 25, p. 679. 1926. Harring and Myers, pp. 332–3. Locality. Lake Wanaka. Temp. 16·5°C. Length of lorica 142μ, toes 70μ. Rare. (P.)

Lepadellidae Colurella obtusa (Gosse) 1886. Colorus obtusus Gosse. The Rotifera, vol. 2, p. 103, pl. 26, flg. 3. Locality. Lake McGregor, Canterbury. Length of lorica 90μ, width 90μ, toes 20μ. Not commno. (P.) Trichocercidae Trichocerca longiseta (Schrank) 1793. Brachionus rattus Schrank. Naturforscher, vol. 27, p. 33. 1886. Mastigocerca bicornis Hudson and Gosse, p. 63, pl. 20, flg. 5. Locality. Peaty roadside pools near Kumara, Westland. Length body 230μ, toe 180μ. Fairly common. (P.) Trichocerca stylata (Gosse) 1851. Monoccrca stylata Gosse. Ann. Mag. Nat. Hist. (2), vol. 8, p. 199. Locality. Lake Alexandrina, Canterbury. Temp. 14·5°C. Length body 150μ, toe 55μ. Fairly common. (P.) Trichocerca (Diurella) stylata (Eyferth) 1878. Diurella stylata Eyferth. Einf. Lebensf., p. 85, pl. 5, fig. 23. [Note. The combination of the genera Trichocerca and Diurella has resulted in T. stylata becoming a homonym. Until the systematic position of these two animals has been determined, the method adopted by other authors is being followed of including the original generic name before Eyferth's animal.] Locality. Lake Alexandrina. Temp. 14·5°C. Length body 180μ, maximum width 55μ, mucrones 35μ. toes 34μ. Fairly common. (P.) Trichocerca plaka Myers. 1938 1938. Myers, Amer. Mus. Nat. Hist. Novitates, no. 1011, p. 7, fig. 31. Locality. Lake McGregor, Canterbury. Length 128μ, toes 46 and 35μ. Fairly common. (P.) Filiniidae Pedalia mira (Hudson) 1871. Pedalion mira Hudson. Month. Micr. Jour., vol. 6, p. 121. 1886. Hudson and Gosse, The Rotifera, p. 132. Locality. Lakes Brunner, Grassmere, Alexandrina, Wanaka. (P.) A discussion of the variabilities of this species will be given under Pedalia fennica. Pedalia fennica (Levander) 1892. Pedalium fennicum Levander. Zool. Anz., vol. 15, p. 403. Locality. Lakes Wanaka, Hawea, Lyndon, Brunner. (P.) Professor Percival suggested that there were two species of Pedalia in the Southern lakes, and examination confirmed this view. In the case of P. mira the number of bristles on the appendages was found in some cases to be less than stated in the original description; also specimens were found with the bristles on the ventral appendage paired instead of separate. Rudimentary bristles were also seen together with specimens having the bristles broken off at the appendage. It is considered that little reliance can be placed on the number and type of the appendage bristles in comparison with the more stable characteristics such as the trophi, and shape of the coronal lip. Only minor differences were noticed in P. fennica. A smaller number of bristles than stated in the original citation was found in the Lake Brunner specimens. Some specimens from the Southern

lakes had a slightly flared coronal lip, but in no case was the deeply grooved lip of P. mira found. In general, the trophi of both species agreed with the original descriptions. Wiszniewski (1933) gives an excellent description of five species of Pedalia together with the variations he has found, and from a study of this paper in conjunction with the original citations it is considered that the specimens are merely geographical variations of P. mira and P. fennica. Finally, it should be noted that Pedalia is not the only genus of the Filiniidae in which there is a marked variability of the appendages. Acknowledgments I am much indebted to Professor E. Percival, of Canterbury University College, for placing at my disposal his large collection of plankton samples from the South Island lakes; to have covered such a large field would have taken several years, and necessitated travelling long distances. I also wish to thank Professor Percival for many helpful suggestions during the preparation of this paper. I have to thank Dr H. Barraclough Fell, of Victoria University College, for arranging for the collection of rotifers from North Island lakes. To Mr P. Malone I am indebted for samples from Kapiti Island. I am also indebted to Dr W. H. Sheffield, Mr G. Stokell, and Miss Vida Baxter, for samples from back-country lakes and rivers. References Ahlstrom, E. H., 1938. Plankton Rotatoria from North Carolina. Jour. Elisha Mitchell Soc., vol. 54, no. 1, pp. 100–101. — 1940. A Revision of the Genus Brachionus and Platyias. Bull. Amer. Mus. Nat. Hist., vol. 77, pp. 143–184. — 1943. A Revision of the Genus Keratella. Bull. Amer. Mus. Nat. Hist., vol. 80, art. 12, pp. 411–457. Harring, H. K., and Myers, F. J., 1920. Trans. Wis. Acad. Sci., Art, Lett., vol. 20, pp. 553–562. — 1924. Ibid., vol. 21, pp. 415–594. — 1926. Ibid., vol. 22, pp. 315–423. Russell, C. R., 1944. A New Rotifer from New Zealand. Jour. Royal Micr. Soc., vol. 64, pp. 121–3. — 1945. A Reference List of the Rotatoria of New Zealand with Ecological Notes. Trans. Roy. Soc. of N.Z., vol. 75, pp. 102–123. — 1946. Additions to the Rotatoria of New Zealand, Pt. 1. Trans. Roy. Soc. of N.Z., vol. 76, pp. 403–408. — 1947. Additions to the Rotatoria of New Zealand, Pt. 2. Trans. Roy. Soc. of N.Z., vol. 77, pp. 351–4. Wiszniewski, J., 1933. Une nouveau Rotifre du genre Pedalia habitant les lacs des hautes mantagnes. Sonderdruck aust Internationale Revue der gesamten Hydrobiologie, Leipzig.