Limnioides melicerta, Weisse, 1848

Wallace, Robert Lee, Kordbacheh, Azar & Walsh, Elizabeth J., 2018, Key to the currently recognized species of Limnias Schrank, 1803 (Rotifera, Monogononta, Gnesiotrocha, Flosculariidae), Zootaxa 4442 (2), pp. 307-318 : 312

Limnias melicerta Weisse, 1848

Figs 1A,B ; 4C

Cephalosiphon limnias Ehrenberg, 1853

Limnias corniculata Ehrenberg, 1853

Limnias annulatus Bailey, 1855; name amended to annulata to agree with feminine genus name

Limnias doliolum Schoch, 1868

Melicerta cubitti Cubitt, 1871 ; text refers to M. annulata , but plate 98 labels as M. cubitti

Limnias granulosa Weber, 1888

Limnias melicerta melicerta: Koste, 1978

Types: None designated

Type locality: Afrossimov Estate , St. Petersburg, Russia.

Other material: Specimen Preparation ANSP 1527.

Diagnosis. Base of tube clear, switching abruptly to a series of clear, stacked rings. Ventral antennae short; dorsal nodules present (n = 7 in 3 rows: 2,3,2). Dorsal gap in corona ciliation approximately equal to neck width. Trophi: rami asymmetrical; uncus with 3 strong main teeth.

Measurements: Total body length, ≤1550 µm; corona width, 160 µm; height, 70 µm; tube width (at top), =100 µm; amictic egg, 130–242 x 40 –98 µm. See also Koste (1978).

Geographic range: Apparently cosmopolitan: Africa ( Democratic Republic of the Congo), Australia, Europe ( France, Germany, Ireland, Russia, U.K.), India, North America ( Canada, U.S.A., Mexico), South America ( Brazil, Ecuador), Thailand.

Ecology: pH, 4.1–8.9; bicarbonate, 57–305 mg /L; calcium, 5–38 mg /L; magnesium, ≤ 20 mg /L, conductivity, 81–686 µS/cm2, temperature, 18–32 °C; colonizes a wide variety of substrata such as glass, charophyte algae ( Chara , Nitella ), aquatic mosses ( Fontinalis , Sphagnum ), and vascular hydrophytes including Ceratophyllum , Elodea , Eriocaulon , Lemna , Ludwigia , Myriophyllum , Nuphar, Nymphaea , Potamogeton , Ranunculus , and Utricularia ( Bailey 1855; Francez 1984b; Kellicott 1888; Koste, 1978; Sarma et al. 2017; Wallace 1977; Yang & Hochberg 2018; pers. obs.). Edmondson (1944) suggests that flat surfaces provide suitable substrata.

Comments. The etymon of this species (G., meli, honey + G., keras, horn) is apparently in reference to the color that the tube of this species may take. Male and diapausing embryos undescribed. Construction of the ringed tube (rings ~5-10 µm in height) is by an elaborate behavior of the animal ( Wright 1954).

Figures

FIGURE 1. Representative morphology of two species of Limnias. (A) Limnias melicerta in ventral view. (NB: Ventral antennae on the opposite side obscured.) Inset: Region of dorsal nodules: (3 rows: 2,3,2). (B) L. melicerta in 3/4 th ventral view. (C) Limnias ceratophylli in 3/4 th ventral view. Symbols: a = algae and debris; b = adult body; c = corona; dn = dorsal nodules; e = amictic embryo; f = foot; rt = ringed tube; s = substratum; st = stucco-like tube (with adhering epiphytes and debris); va = ventral antennae; bars ~100 µm. (Photomicrographs B and C are courtesy of Michael Plewka.)

FIGURE 4. Coloniality in Limnias. Bar = 500 µm.