The World of Protozoa, Rotifera, Nematoda and Oligochaeta
Dipleuchlanis
Dipleuchlanis de Beauchamp, 1910
ref. ID; 1663
Dorsal plate flat much smaller than arched ventral plate. Cuticle connecting the dorsal and ventral plates in the form of a deep groove dividing the body cavity into two unequal portions. Toes long and parallel-side and straight. (ref. ID; 1663)
ref. ID; 3246
Body ovoid, much compressed dorso-ventrally. Lorica of two plates, the dorsal being concave or nearly straight, obtusely pointed posteriorly and much smaller than the ventral, which is convex and rounded behind. The cuticle connecting the two plates is in the form of a deep groove, and divides the body cavity into two unequal portions, of which the ventral is much the larger and contains the greater part of the organs. The lateral edge of the two plates are nearly parallel and somewhat elevated. The foot is short and slender, without setae on the penultimate joint. The toes are long, very slender, cylindrical, parallel-sided and slightly swollen at the bases. The head is large and is connected with the anterior edge of the lorica by a stiffened cuticular membrane. The face is inclined ventrally. The corona is of family type. The mastax is modified malleate type. The unci each have ten or more long, slender teeth. The rami are triangular and carry on the inside of each tip a very minute denticular comb. The remaining anatomy is similar to that of Euchlanis. (ref. ID; 3246)
Dipleuchlanis propatula f. macrodactyla (ref. ID; 2834)
Descriptions
The anterior end of the ventral plate is more or less straight with a slight hump in the middle flanked by two slight depressions. Dorsal plate is much narrower than the ventral plate. Toes, long, measures more than two-thirds the body length. (ref. ID; 2715)
Measurements
Length of ventral plate 142; length of dorsal plate 132; width of ventral plate 137; width of dorsal plate 89; toe 115 µm. (ref. ID; 2715)
The new species can easily be distinguished from all congeners, especially the closely related D. propatula (Gosse), by the transversally undulate dorsal and ventral lorica. (ref. ID; 2844)
Descriptions
Lorica elongate, with dorsal and ventral plate, deeply invaginated membranous lateral connections. Ventral plate broadest, convex, transversally undulate. Dorsal plate concave, with median convexity. Head aperture dorsally straight, ventrally concave. Lateral antennae present in distal part of body, on ventral part of lateral sulci. Foot with two pseudosegments. Toes long, parallel-sided, pointed distally. Trophus: Manubria proximally broad, with straight cauda, unci with 7-8, partially connected teeth, rudimentally anterior tooth fused with major tooth. Minute comb-like projections on rami tips not observed. Fulcrum widened distally in lateral view. (ref. ID; 2844)
Male: Male unknown. (ref. ID; 2844)
Etymology
The species name is derived from the Latin ornatus, and alludes to the remarkable lorica. (ref. ID; 2844)
Both the dorsal and ventral plates in the anterior end have median sinuses. Though at first sight D. propatula can be mistaken of D. macrodactyla a close examination reveals differences. Toes of D. propatula are not as long as the toes of D. macrodactyla and also there are differences in the anterior margin especially of the ventral plate. In some preserved specimens the foot had not contracted into the lorica; making the toes appear longer than they really are. (ref. ID; 2715)
Body oval, truncate in front, rounded behind. Dorsal plate concave and smaller than ventral plate all around, posterior portion gradually narrowing, being obtusely pointed at the posterior end. Ventral plate convex. Lateral edges of the two plates nearly parallel. Foot short, slender, three-jointed. Toes very long and slender. (ref. ID; 3180)
The corona of this species is of the family type and is ventrally inclined. The head is large and connected with the anterior edge of the lorica by a cuticular membrane. The shape of the body is oval, truncate in front, rounded behind. The dorsal plate is concave and smaller than the ventral plate all around. The posterior portion gradually narrowing, being obtusely pointed at the posterior end. The ventral plate is convex. The dorsal and ventral plates are connected by a deep groove that seems to be slightly more stiffened than the cuticle forming the lateral sulci in the genus Euchlanis. The lateral edges of the two plates are nearly parallel and somewhat elevated above the planes of the plates themselves. The foot is short, slender and three jointed; there are no setae on the dorsal side of the penultimate foot-joint. The toes are very long, parallel sided, very slender, cylindrical and slightly swollen near their bases. Individuals occur with perfectly straight toes, and with the toes curved outwards, varying somewhat in length in specimens from different locations; the average would be about one-half the length of the dorsal plate. The dorsal and lateral antennae are of the normal Euchlanid type, in the usual positions. The mastax is of the modified malleate type. The rami are triangular in ventral view, and the unci each have ten, or more, long, slender, teeth, clubbed at the tips. There are a pair of very minute denticular, fan-shaped combs, one on the inner tips of each ramus. (ref. ID; 3246)
Measurements
Lorica length 175; length of toes 85 µm. (ref. ID; 1837)
Length of ventral plate 165; length of dorsal plate 151; width of ventral plate 135; width of dorsal plate 102; width at anterior margin 87; toes 99 µm. (ref. ID; 2715)
Total length 276; head 42x60; body 140 long; anterior extremity 78 wide, 60-76 high; widest part 110-120; highest part 80-120; toes 82-88 µm. (ref. ID; 3083)
Length of lorica 170-200; length of toes 70-110 µm. (ref. ID; 3246)
Length 160 µm, toes 96 µm. (ref. ID; 3387)
Hauer (1965) defined a new species from the Parana de Xiborena, which showed long toes and an indentation on the ventral margin of the head shell. Compared with many other specimens from Amazonia (Koste 1972) this species is a juvenile individuum of the type species where the proportions of the body to the toe were not yet completely developed. In tropical lakes we can find specimens with a greater lorica and longer toes. In the Nhamunda area we sometimes found slim forms which are in our mind not new species but modifications. (ref. ID; 2834)
Measurements
Body length 144; body high 100; toe 140 µm. (ref. ID; 4606)
