Sphyrias
Sphyrias Harring, 1913
ref. ID; 1663
Head very broad and truncate anteriorly. Two eyespots widely separated on protuberances. Foot annulated. Carnivorous littoral species. (ref. ID; 1663)
ref. ID; 1923
Corona consists of several rows of cilia on bulging surface. Easily distinguishable by corona and shape of body. (ref. ID; 1923)
ref. ID; 3245
Notommatids rotifers with short, broad, saccate, illoricate body the head is very broad and truncate anteriorly and has two short, stumplike lateral projections; it is separated from the abdomen by a well marked constriction; the abdomen is subsquare and ends in a colloarlike tail; the foot is long and wrinkled; the toes are short, conical, and obtusely pointed. The corona consists of two roughly circular wreaths of long cilia at the edges of the short, lateral projections of the head; the anterior surface of the head is unciliate; the mouth is near the ventral margin and strongly protrusile. The mastax is virgate; the rami are roughly triangular and strongly curved, the inner margins armed with numerous short closely spaced, needlelike teeth; the fulcrum and manubria are long, straight rods; the unci have only a single functional tooth; the piston is very large. The retrocerebral organ is rudimentary; the two eyespots are on the lateral projections of the head. (ref. ID; 3245)
- Sphyrias lofuana (Rousselet, 1910) (ref. ID; 1345, 1663, 1923, 2017, 2833, 3245)
Syn; Notops lofuana Rousselet, 1910 (ref. ID; 1345, 2017, 3245); Sphyrias lofuana Harring, 1913 (ref. ID; 3245)
Sphyrias lofuana (Rousselet, 1910) (ref. ID; 1345, 1663, 1923, 2017, 2833, 3245)
Synonym
Notops lofuana Rousselet, 1910 (ref. ID; 1345, 2017, 3245); Sphyrias lofuana Harring, 1913 (ref. ID; 3245)
Descriptions
The body of this species is short, stout and truncate anteriorly; its greatest width is about one half of the total length. The integument is moderately flexible and the outline is constantly changing in response to the violent contractions of the animal. It is a moderately transparent species. The head and abdomen are separated by a deep transverse fold. The outline of the head is variable; when the animal is at rest (as represented in the figures), it is broadly triangular and wider than the abdomen; when it is swimming, the mouth region is retracted and the head becomes squarely truncate. The abdomen is subsquare in dorsal view, truncate posteriorly and ends in a short, very wide, collar-like tail, surrounding the base of the foot; it is marked dorsally with strong, longitudinal folds, gradually disappearing on the sides. The foot is fairly long and wrinkled, but not jointed. The two toes are somewhat obtusely pointed, slightly decurved and laterally compressed; their length is about one tenth of the total length. The tubular dorsal antenna is on the abdomen, immediately behind the transverse fold, and jointed to the integument in its entire length. The lateral antennae are small, rounded, knoblike, setigerous papillae just above and in front of the tail. The corona is perhaps easier to understand if it is considered as a simplified or specialized Eosphora-corona. As explained under this genus, its corona consist of a circumapical band of cilia, interrupted dorsally, with a lateral arc of very long cilia for propulsion, and an inner arc of fairly long cilia jointed to the circumapical band at both ends. In Sphyrias the dorsal gap in the corona is almost equal to the width of the head, and all that remains of the circumapical band is the lateral, auricle-like arc of long cilia; in front of this is a short arc of fairly long cilia, representing the inner arc of Eosphora. Nothing remains of the latero-ventral arc of the circumapical band normally joining the auricles and passing below the mouth except a few short cilia at the sides of the vertical, slitlike mouth. The mouth region is retracted when the animal swims, and the inner arc of cilia thus forced out even with the external or posterior arc; this produces an appearance recalling the form of the hammerhead shark (Sphyrna, in Rafinesque's Greek!). At the point of attachment of the dorsal longitudinal muscles are four small tufts of sensory setae. The mastax is virgate, but adapted also to prehension. The fulcrum is very long and straight; it is formed of two plates joined together at the edges and forming a V-shaped trough with the apex dorsal. The rami are symmetrical and roughly triangular; their inner edges are armed with about twenty long, needle-like teeth. The unci have only a singe, long tooth, clubbed at the tip and with a minute basal plate. The manubria are long, rodlike and nearly straight; they diverge from the incus at an angle of nearly 45 degrees. Two straight rods, expanded at their dorsal ends into triangular plates, are imbedded in the walls of the mastax below the dorsal branch of the rami and aid in the support of the mastax during the pumping action. The piston is large and powerful; its striate longitudinal muscles are very conspicuous. In the ventral angles of the mastax are two well developed salivary glands. The oesophagus is moderately long and slender. There is no constriction between the stomach and intestine. The ovary is very long and ribbon-shaped and passes dorsally over the stomach into the head segment. The gastric glands and bladder are normal. The foot glands are slender, slightly clubshaped and nearly as long as the foot. The ganglion is large and saccate. At its posterior end is a small, spherical, ductless retrocerebral sac and two granular areas at the external angles of the ganglion appear to represent the remains of the subcerebral glands. The two eyespots are on rounded, knoblike projections between the lateral arcs of cilia. (ref. ID; 3245)
Comments
In spite of the somewhat aberrant external form this species is closely related to Eosphora and Eothinia, as shown by a comparison of the mastax and corona. Its food seems to consist principally of the smaller Bdelloids and Conochius, whose trophi are often found in the stomach. (ref. ID; 3245)
Measurements
Total length 275-300; toes 35-30; trophi 62 µm. (ref. ID; 3245)