The World of Protozoa, Rotifera, Nematoda and Oligochaeta
Anuraeopsis
Anuraeopsis Lauterborn, 1900
Class Rotatoria: Order Ploimida: Family Brachionidae (ref. ID; 7097)
ref. ID; 1663
Lateral edges of dorsal and ventral plates of lorica connected by infolded cuticle. Ventral plate flat, dorsal plate arched. Mastax malleate. (ref. ID; 1663)
ref. ID; 3074
Egg-carrying method. (ref. ID; 3074)
ref. ID; 3114
Usually species are identified by means of the following character (Voigt): 1) general shape of the body, 2) shape of occipital edge of the lorica, 3) colour of the body, 4) surface pattern of lorica (punctuated or not), 5) body length. These characters are variable in both living and fixed materials. (ref. ID; 3114)
According to Sudzuki (1957), 1) shape of the posterior extremity of the lorica, 2) height of the body (at both parts: head and caudal end), 3) shape of the antero-lateral margins, 4) site of lateral antennae, etc are good criteria. (ref. ID; 3114)
With granulated lorica and with U-shaped sinus at the anterior end. (ref. ID; 1805)
Lorica granulated, with U-shaped sinus at the anterior end. (ref. ID; 2704)
There is a 'U' shaped sinus in the anterior ends and no teeth are present inside the sinus. Small teeth are present outside the anterior sinus. Lorica pustulated. (ref. ID; 2715)
This species is characterized by having 1) ornamentation on both middle and caudal parts of the dorsal lorica and 2) gently pointed caudal extremity. It is distinguishable from the lata group by 1) features of the caudal half tapering gradually toward extremity, 2) presence of a paired antero-lateral plaques and 3) Y-shaped (usually) mid-dorsal ridges. (ref. ID; 3083)
Comments
This species was originally described as A. navicula coelata by Beauchamp (1932: 238, Fig.2), then as A. fissa coelata by Berzins (1962: 40) and as A. coelata coelata by Koste (1978: 132). On this point, Sudzuki agree with Koste. While, the species from India and identified as coelata by Wulfert (1966: 57-58, Fig.1) could be treated as a distinct subspecies under coelata, for convenience here coelata wulferti, since it has 6-7 paired facets or plaques along whole lateral margins and antero-lateral knobs (outside lobed occipital projections) with many short spines. (ref. ID; 3083)
Measurements
Lorica length 74; maximum width 42 µm. (ref. ID; 2704)
Length of lorica 112; width 50 µm. (ref. ID; 2715)
Different from coelata Beauchamp, 1932 from Eastern Africa in the presence of 1) a paired knob-like occipital protuberance but unlike fissa beauchampi Berzins, 1962 from Israel and coelata Nogrady (1983: 49, Fig.29) from Kenya, 2) two lobed pectoral margins like Keratella, 3) V-shaped rather than Y-shaped dorsal ridges which are scarcely ever or never widen at the anterior part, 4) features of caudal part suddenly tapering from posterior 1/3 of the lorica and 5) dorsal ridges running parallel barely arrive at 1/3 of body length for both extremities (parallel running of dorsal ridges arrive at 1/4 of body length from the extremity in coelata coelata). It is also demarcated from coelata wulferti in having a slender form and lack of strongly developed spines on the occipital margin and many marginal facets. (ref. ID; 3083)
Etymology
This species is named after Mr. Lin Keh Jeng, my student at the Nihon Daigaku University during 1983-1987, who assisted me as an excellent guide and interpreter in Taiwan. (ref. ID; 3083)
Lorica finely stippled, more or less cylindrical and obtusely pointed posteriorly. (ref. ID; 1805)
Many of the animals carried eggs 62 µm long attached by a nipple. (ref. ID; 2277)
The author has had the opportunity of studying the so-called "organe membraneux" described by Weber (1898, p.716) and Donner (1943, p.29). At intervals of 10-20 seconds this organ was extended between the parts of the lorica, and remained for a couple of seconds or slightly longer in this stretched-out position. While the organ was extended the animal remained in general quiet. (ref. ID; 2553)
Egg: I have prepared two figures of resting eggs. No such eggs have been pictured in the earlier literature, but Voigt (1904, p.89) describes the resting egg as "zart chagriniert". The length and breadth of the two eggs are 80 and 45 µm, and 75 and 42 µm, respectively (Voigt gives the figures 68 and 41 µm). (ref. ID; 2553)
Lorica made of two plates dorsal and ventral. The dorsal plate is round. (ref. ID; 2715)
This species is clearly distinguishable from others in the possession of 1) truncated caudal extremity, 2) nearly straight pectoral margin, 3) stand-up collared or V-shaped occipital margin, 4) a pair of knoblike projections at the antero-lateral corner, 5) central position of the widest & highest parts, 6) depressed, oblique occipital margin, 7) upward posterior portion like Pompholyx and 8) stocky body. The Weber's organ hardly observable in the fixed materials. (ref. ID; 3083)
At a glance, this species is reminiscent of navicula Rousselet, 1910, since it had a naviculoid ridgeline on the dorsal surface. This species was, however, characterized by having a frontal margin of the dorsal plate pointed or nearly pointed toward the center. Pectoral margin two-lobed (never straight as in navicula). The body rather stocky and the caudal extremity wide and truncated as in fissa. (ref. ID; 2587)
This species is characterized by having one conical caudal projection on the dorsal plate, which may be sometimes errorneously recognized as in navicula. Instead, the caudal extremity of dorsal plate is truncated as in fissa. (ref. ID; 2587)
Measurements
Lorica length 68-75 (dorsal), 60-70 (ventral); greatest width 40-42 (dorsal), 38-40 (ventral); height 35-38; width of pectoral extremity 33-35; width of caudal extremity 13-15 (dorsal), 10-13 (ventral); caudal elongation of dorsal plate 8-10 long, 10-12 wide at the base. (ref. ID; 2587)
This species resembles A. fissa lata Berzins, 1962 from Cambodia in having a saclike and widest position of lorica, but differs from it in the possession of 1) a pair of occipital projections much longer and more strongly bent inward like caudal protuberance of angularis-dolaburatus group of Brachionus, 2) 3-4 pairs of postero-lateral plaques, 3) lateral feelers located on the 3rd lateral plaques from caudal extremity and 4) very wide and semi-circular caudal part. In addition, this species is fundamentally different from fissa in the lateral view; the height is nearly even from anterior to posterior and the posterior part is downward in the former, but the highest part is located in the middle and the lowest in the caudal extremity, which is bent upward in the latter. Needless to mention, but it is also district from navicula in having oblique occipital margin, ornamentation, general shape of lorica as well as features of frontal margins. It differs from coelata in general shape, ornamentation of lorica and presence of antero-lateral knobs. (ref. ID; 3083)
Comments
Anuraeopsis fissa lata established by Berzins (1962: 40-41) is dealt with A. coelata lata by Koste (1978: 132). Sudzuki consider, however, that A. fissa lata Berzins should be treated as A. lata lata, since the species is distinct from any one of navicula, coelata and fissa at the species level. (ref. ID; 3083)
Type locality
Krangi reservoir and East coast part pond in Singapore. (ref. ID; 3083)
Dorsal lorica spindle-shaped, its widest part near the middle but the caudal half usually tapering gently than the anterior one, since the latter often pointed although provided with a cleft in the middle. Ventral lorica is like a triangular flag; its widest part near the anterior extremity is 2-lobed in shape and spinous along the margin. Caudal part is rather round than truncated, not only in the dorso-ventral but also in the lateral view and much more elongated than in fissa. (ref. ID; 3083)
Comments
The specimen is not so different from those of Rousselet (Voigt 1957, Fig.15) from Sri Lanka (dorsal lorica width/dorsal lorica length 0.45, ventral lorica width/ventral lorica length 0.43) and Hauer (1937, Fig.9) from Java (dorsal lorica width/dorsal lorica length 0.49, ventral lorica width/ventral lorica length 0.47) except for size, relative width of lorica and position of both widest and highest parts. Berzins (1962: 37-40) regarded Rousselet's species as A. fissa navicula following Ahlstrom (1938), and the Hauer's as A. fissa haueri Berzins, 1962. However, Sudzuki consider these species should be treated under A. navicula. (ref. ID; 3083)