Conochilidae Harring 1913
Creators: name: Davies, Natalie
name: Lafleur, Alexandre
name: Hochberg, Rick
name: Walsh, Elizabeth J.
name: Wallace, Robert L.
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Rotifera
Eurotatoria
Flosculariaceae
Conochilidae

description: Dichotomous key to species in family Conochilidae
1 Corona circular (not horseshoe-shaped) with prominent ventral gap absent; ventral (= lateral) antennae not within the corona; resting eggs with spiral furrow, but no hatching furrow evident; body length ~500 µm; monospecific genus................................................................ Conochilopsis causeyae (Vidrine, McLaughlin, & Willis, 1985) [Segers and Wallace (2001) described its trophi and reallocated it to a new genus in Conochilidae.]
1’ Corona horseshoe-shaped with a prominent ventral gap....................................................... 2
2(1’) Ventral (= lateral) antennae within corona; colonies of several to many individuals; resting eggs not ornamented, but possess a hatching furrow; genus Conochilus (Fig. 5)................................................................. 3 [Trophi for the two species in genus Conochilus were (SEM) are found in Segers & Wallace (2001).]
2’ Ventral (= lateral) antennae not within corona; resting egg with spiral surface texture, but no hatching furrow evident; genus (Conochiloides) Conochilus ............................................................................. 4 [Trophi for the four species in the former genus Conochiloides were drawn by Ahlstrom (1938); SEMs of the trophi for C. dossuarius and C. natans are shown in Segers and Wallace (2001).]
3(2) Antennae not fused; colonies of 30–100 individuals; total body length 400–850 um (foot:body ratio, 2.2–2.4).......................................................................................... hippocrepis (Schrank, 1803)
3’ Antennae fused (except perhaps at distal end) into a single structure; small colonies (5–30 individuals) with total body length 200–450 um and foot:body ratio, 1.2–1.7 or larger colonies (50–400 or more individuals) with total body length <1300 µm (foot:body ratio 2.2–2.7)............................................................ unicornis Rousselet, 1892 [Includes a form previously known as Conochilus norvegicus Burckhardt, 1943 that produces colonies often with large numbers of individuals possessing elongate bodies that may be the result of allometric growth (Edmondson 1959; Ruttner-Kolisko 1974). De Graaf (1953) provided information on the commensal protists that inhabit the gelatinous matrix and Yang et al. (2021) provided information on the ultrastructure of the secretions.]
4(2’) Antennae not fused; rami symmetrical, with 5–6 large clavate teeth on each uncus; total body length 280–510 µm............................................................................................ natans (Seligo, 1900)
4’ Antennae at least partially fused; rami symmetrical or not; variable number of large clavate teeth on each uncus.......... 5
5(4’) Rami strikingly asymmetrical, one side almost triangular in shape, the other sub-rectangular; 5 clavate teeth on each uncus; total body length 280–500 µm.......................................................... dossuarius (Hudson, 1885)
5’ Rami symmetrical or at least asymmetry scant.............................................................. 6
6(5’) Unci with 3/3 teeth; total body length 200–250 µm..................................... coenobasis (Skorikov, 1914) [Amphoteric females are known in this species (Ruttner-Kolisko 1974).]
6’ Unci with 4/5 teeth; total body length 170–190 µm........................................ exiguus (Ahlstrom, 1938) [An amphoteric female is shown in Fig. 5D.]
description: Published as part of Davies, Natalie, Lafleur, Alexandre, Hochberg, Rick, Walsh, Elizabeth J. & Wallace, Robert L., 2024, Key to sessile gnesiotrochan rotifers: Families, monospecific species in Flosculariidae, species of Atrochidae, Conochilidae, and Limnias, pp. 497-520 in Zootaxa 5397 (4) on page 507, DOI: 10.11646/zootaxa.5397.4.3, http://zenodo.org/record/10469053