Main Content

The World of Protozoa, Rotifera, Nematoda and Oligochaeta

[ref. ID; 4875 (Wilhelm Foissner, 1995/96)]

Class Karyorelictea

Order Loxodida Jankowski, 1978

Small (~30 um) to very large (~1 mm) Karyorelictea with specialized dorsolateral kinety and epipellicular mucus and/or scale layer, lacking in family Loxodidae, on left body surface. Body laterally strongly compressed, right side completely ciliated, left barren except for single, circular (?) marginal kinety. Oral apparatus subapical on concave body surface, slit-like, secondarily (?) reduced in family Kentrophoridae; buccal overture +/- completely surrounded by two specialized kineties, within oral cavity single, intrabuccal kinety (adoral?). Somatic and oral ciliature composed of dikinetids throughout, specialized and condensed in anterior region of cell. Stomatogenesis possibly buccokinetal. Primarily psammophilic forms, all marine except for Loxodes.


Most higher loxodid taxa were found by Jankowski (1967, 1978, 1980). Unfortunately, he provided poor, almost useless definitions based solely on the very incomplete literature data. I shall thus redefine all taxa, using results from the present paper and from the more recent literature (Corliss 1979; Foissner 1995, 1996; Puytorac 1994). Jankowski's overhasty taxa raising and poor definitions certainly discourage more serious workers and cause many nomenclatural problems, as indicated by the ambiguous authorships ascribed, e.g., by Small & Lynn (1985) to Jankowskian categories, viz. "order Loxodida Jankowski, n. ord., respectively, Kentrophoridae Jankowski, n. fam.".


First defined in Jankowski (1978) as "phagotrophic pleurostomatids with diploid macronucleus". Later, Jankowski (1980) provided equally vague diagnoses for two new suborders, viz. "Order Loxodida Jankowski, 1978 with diploid macronucleus. Free-living in marine benthos. Type: Loxodes. Two suborders can be distinguished according to the structure of the peristome: Loxodina s. str., subordo n. (type Loxodes: with very large and complex oral apparatus) and Cryptopharyngina subordo n. (type Cryptopharynx; with inconspicuous, simple oral apparatus)". The present results do not support Jankowski's view because the somatic and oral infraciliature of Cryptopharynx and Loxodes are almost identical.

Type family (by original designation)

Loxodidae Butschli, 1889

Family Loxodidae Butschli, 1889

Medium-sized (~100 um) to very large (~1 mm) Loxodida with one to many gravity receptors (Muller vesicles) at dorsolateral margin and buccal kineties interrupted at anterior, projecting buccal vertex. Intrabuccal kinety long and rectilinear. Muller vesicles with single or compound barium or strontium granule, each vesicle associated with single dikinetid of left lateral ciliary row. Buccal overture and posterior, style-shaped portion of buccal cavity (pharynx) distinct because heavily pigmented. Marine and freshwater.

Type genus (by monotypy)

Loxodes Ehrenberg, 1830

Another genus

Remanella Foissner, 1996

Family Cryptopharyngidae Jankowski, 1980

Small (~30 um) to medium-sized (~150 um) Loxodida with dorsolateral kinety extending onto ventral side. Left body surface covered with distinct, ornamented scales embedded in mucuous layer. Buccal kineties continuous, intrabuccal kinety short and curved or long and clip-shaped; buccal overture roundish to ellipsoid, indistinct because not pigmented and narrow. Marine.


The family is dated with 1980, i.e. the subordinal rank lowered and taken as date of family foundation because Jankowski (1967) mentioned the family name only, which is insufficient according to the ICZN.

Type genus (by original designation)

Cryptopharynx Kahl, 1928

Another genus

Apocryptopharynx nov. gen.

Family Kentrophoridae Jankowski, 1980

Loxodida with very likely functionless oral structures reduced to nematodesmata-bearing, condensed dikinetids in anterior body region. Left side covered with thick mucuous layer inhabitated by symbiotic sulphur bacteria phagocytised through cell surface and used as food source.


For nomenclature see Foissner (1995). Jankowski (1978) erected a new order, Thysanophorida (later named Kentrophorida, Jankowski 1980), and then (Jankowski 1980) even a new subclass, Symbiophagina, for this monotypic family. Both are inacceptable at the present state of knowledge. Jankowski provided no evidence for the raise in rank.

Type genus (by monotypy)

Kentrophoros Sauerbrey, 1928