Conochilus

Conochilus Ehrenberg, 1834 (ref. ID; 1345, 2715, 3591, 3688, 4596) or 1835 (ref. ID; 3514), Hlava (ref. ID; 1923)

Quote from ref. ID; 2261

Class Rotatoria: Order Monimotrochida: Family Conochilidae (ref. ID; 7097)

[ref. ID; 1663]
Colonies composed of radiating individuals inhabiting coherent gelatinous tubes. With one or two antennae on the corona. With a ventral gap in the ciliary wreath. Mouth on the corona, nearer the dorsal edge. Limnetic species. (ref. ID; 1663)

[ref. ID; 1923]
The structure of the antenna varies in different populations. (ref. ID; 1923)

[ref. ID; 3017]
The females from spherical colonies of radially orientated individuals where the "feet" emanate from a common center. Glandular cells at the base of the foot secrete a mucus which forms a central jelly common to the entire colony. (ref. ID; 3017)

[ref. ID; 3591]
Subgenus; Conochilus Ehrenberg, 1834 (ref. ID; 3591)
Diagnosis; Colonial Conochilidae. Corona horse-shoe shaped, slanted ventrally. Mouth dorsally, antennae apically inside coronal field. Resting egg smooth. Trophi of Conochilidae type. (ref. ID; 3591)
Type species (monotype); Conochilus hippocrepis (Schrank, 1830) Ehrenberg, 1834 (ref. ID; 3591)

Subgenus; Conochiloides Hlava, 1904 (stat. nov.) (ref. ID; 3591)
Diagnosis; Solitary Conochilidae. Corona horse-shoe shaped, perpendicular to body axis, Mouth central inside coronal field, antennae dorsally outside coronal field, resting egg ornamented with spirals. Trophi of Conochilidae type. (ref. ID; 3591)
Type species; Conochiloides natans (Seligo, 1900) Hlava, 1904 (ref. ID; 3591)

[ref. ID; 4596]
Antennae on the corona. (ref. ID; 4596)

  1. Conochilus coenobasis (Skorikov) (ref. ID; 1831), (Skorikow, 1914) (ref. ID; 2757)
    Syn; Conochiloides coenobasis Skorikow, 1914 (ref. ID; 2757)
  2. Conochilus dorssuarius (Hudson, 1875) (ref. ID; 1808), 1885 (ref. ID; 2757) or 1914 (ref. ID; 2593)
    See; Conochiloides dossuarius (ref. ID; 1346, 3514, 3688)
    Syn; Conochiloides dossuarius (Hudson, 1885) (ref. ID; 2757)
  3. Conochilus dorssuarius var. coenobasis (Skorikov, 1914) (ref. ID; 1847)
  4. Conochilus hippocrepis (Schrank, 1803) (ref. ID; 3275, 3688) or 1830 (ref. ID; 1345, 1346, 1923, 2276, 2317, 2551, 2757, 2827, 3514, 3591, 4596) reported year? (ref. ID; 3029, 3259, 5022) reported author and year? (ref. ID; 2989, 3017, 5389, 6844)
    Syn; Conochilus hippocrepis Harring, 1913 (ref. ID; 3688); Conochilus volvox Ehrenberg, 1834 (ref. ID; 1345, 1346, 2276, 2757, 3017, 3514, 3688); Lacinularia volvox Schoch, 1868 (ref. ID; 1345, 3688); Linza hippocrepis Schrank, 1803 (ref. ID; 3688) or 1830 (ref. ID; 1345, 1346); Linzia hippocrepis Schrank, 1803 (ref. ID; 3275) or 1830 (ref. ID; 2276, 2317, 2385, 3514); Megarlotrocha volvox Gosse, 1862 (ref. ID; 1345, 3688); Ptygura volvox Dujardin, 1841 (ref. ID; 1345, 3688)
  5. Conochilus leptopus Forbes, 1893
    See; Conochilus unicornis (ref. ID; 1345, 3688)
  6. Conochilus limneticus Stenroos, 1898
    See; Conochilus unicornis (ref. ID; 1345, 3688)
  7. Conochilus natans (Seligo, 1900) (ref. ID; 1808, 2757)
    Syn; Conochiloides natans Halva, 1904 (ref. ID; 2757); Tubicolaris natans Seligo, 1900 (ref. ID; 2757)
  8. Conochilus natans Voigt, 1902 (ref. ID; 3688) or 1904 (ref. ID; 1346)
    See; Conochiloides natans (Seligo, 1900) (ref. ID; 1346, 3688)
  9. Conochilus norvegicus Burckhardt, 1943 (ref. ID; 1345, 1923, 2553, 3591)
  10. Conochilus unicornis Rousselet, 1892 (ref. ID; 1345, 1346, 1923, 2268, 2317, 2551, 2715, 2841, 3275, 3514, 3591, 3688, 4596) reported year? (ref. ID; 3046, 3208) reported author and year? (ref. ID; 2989, 3017)
    Syn; Conochilus leptopus Forbes, 1893 (ref. ID; 1345, 3688); Conochilus limneticus Stenroos, 1898 (ref. ID; 1345, 3688)
  11. Conochilus volvox Ehrenberg, 1834
    See; Conochilus hippocrepis (ref. ID; 1345, 1346, 2757, 3514, 3688)

Conochilus dorssuarius (Hudson, 1875) (ref. ID; 1808), 1885 (ref. ID; 2757) or 1914 (ref. ID; 2593)

See

Conochiloides dossuarius (ref. ID; 1346, 3514, 3688)

Synonym

Conochiloides dossuarius (Hudson, 1885) (ref. ID; 2757)

Descriptions

On the corona the trochus forms an upright hood; there are two distinct cingular bands above one another. There are two large red eyespots just below the cingulum. The ventral antennae are remarkably long, originating from a base but well separated as in C. coenobasis. Trophi symmetrical with three large teeth on each side and a few faintly visible additional teeth, but not at all like the C. dossuarius trophi shown by Hauer (1963). Foot ringed, 4-5 footglands. The animals are solitary, in a very delicate gelatinous tube. (ref. ID; 2593)

Comments

Our specimens agreed well with the classical description of C. coenobasis. We do go along however with the combination of the genera Conochilus and Conochiloides as well as the synonymy of C. coenobasis and dossuarius as suggests by Pejler (1962) and Ruttner-Kolisko (1972). (ref. ID; 2593)

Measurements

Body length 230; foot 160; antennae 110-120 um. (ref. ID; 2593)

Conochilus hippocrepis (Schrank, 1803) (ref. ID; 3275, 3688) or 1830 (ref. ID; 1345, 1346, 1923, 2276, 2317, 2551, 2757, 2827, 3514, 3591, 4596) or reported year? (ref. ID; 3029, 3259, 5022) reported author and year? (ref. ID; 2989, 3017, 5389, 6844)

Synonym

Conochilus hippocrepis Harring, 1913 (ref. ID; 3688); Conochilus volvox Ehrenberg, 1834 (ref. ID; 1345, 1346, 2276, 2757, 3017, 3514, 3688); Lacinularia volvox Schoch, 1868 (ref. ID; 1345, 3688); Linza hippocretis (Schrank, 1803) (ref. ID; 3688) or 1830 (ref. ID; 1345, 1346); Linzia hippocrepis Schrank, 1803 (ref. ID; 3275) or 1830 (ref. ID; 2276, 2317, 2385, 3514); Megarlotrocha volvox Gosse, 1862 (ref. ID; 1345, 3688); Ptygura volvox Dujardin, 1841 (ref. ID; 1345, 3688)

Descriptions

This species form colonies of about 100 animals. Common in pond. C. hippocrepis with 2 antennae, which often found with unequal, the left being as small as half the length of the right. The stomach is partially divided into 2 unequal chambers by an asymmetrically placed paramedian partition. This species may accumulate in great numbers in shadows of lily pads and sticks in quiet ponds. (ref. ID; 1923)
All the Wisconsin specimens examined had the antennae of unequal length, the left one being the shorter in all cases. There was considerable variation in the difference; in some the two were almost equal, in others the left antenna was only half as long as the right. This has also been observed in specimens from Maine and New Hampshire. In many localities they are equal. Cohn (1862) figured asymmetrical antennae but said nothing about them in the test. Apparently, no other observer recorded unequal antennae. (ref. ID; 3259)
With two antennae on corona. Colonies with many individuals. Freshwater species, also in estuaries. (ref. ID; 4596)
SEM micrograph illustrating trophi. (ref. ID; 6844)

Comments

Comparison of C. hippocrepis and C. unicornis. C. hippocrepis builds larger colonies (60-124 ind.) than C. unicornis (approx. 15, but max. 25) and the single individuals are also longer (500-800 um) than the individuals of C. unicornis (up to 370 um) (Buckhardt 1944). A more distinct difference between the two species is that C. hippocrepis always has 2 lateral antennae, while C. unicornis usually has 1. Forms with an intermediate design are well known (Buckhardt 1944; Pejler 1956). (ref. ID; 2989)
C. hippocrepis is the first known. C. unicornis was discovered it was given its name with reference to a distinct differential character in comparison with C. hippocrepis, viz. the occurrence of only on lateral antenna. Nevertheless, Burckhardt (1944) has found in some lakes situated high in the Alps and in northern Spain, undoubted individuals of C. unicornis with paired lateral antennae. This caused Burckhardt to undertake a detailed morphological investigation of the two species, based mainly upon material from the Alps. He arrived at the result that several earlier noticed features till proved to be good distinguishing characters, but in addition he discovered a number of new ones so that, according to him, the two species are distinguished by at least 7 characters, apart from the based on the antennae, which is less reliable. The species are also said to differ in their ecological occurrence. (ref. ID; 3017)

Measurements

Total length varies up to about 800 um. (ref. ID; 1923)
Total length of specimens about 550 um. (ref. ID; 2317)
Colonies about 300-400 um in diameters. (ref. ID; 2385)
Length of body 500-800 um. (ref. ID; 4596)

Conochilus norvegicus Burckhardt, 1943 (ref. ID; 1345, 1923, 2553, 3591)

Descriptions

Burckhardt designated a very large unicorn form (1,300 um) with greatly elongate foot as C. norvegicus, but this species is synonym of C. unicornis, might represent a case of gigantism and allometric distortion in a population adapted to low temperature. (ref. ID; 1923)

Comments

The results accounted for by Pejler (1956) ought to demonstrate that C. norvegicus can no longer be retained as a distinct species. Some of Lie-Pettersen's specimens (e.g. that shown in Lie-Pettersen 1909, Pl.1:5) are admittedly more robust than the two parent species, and have above all a considerably longer foot than they, but this can be interpreted as an effect of heterosis, and does not oppose their presumed hybridogenic character. The possibility that we are here in presence of polyploidy likewise exists; cf. Carlins 1943, p.75. (ref. ID; 2553)

Conochilus unicornis Rousselet, 1892 (ref. ID; 1345, 1346, 1923, 2268, 2317, 2551, 2715, 2841, 3275, 3514, 3591, 3688, 4596) reported year? (ref. ID; 3046, 3208) reported author and year? (ref. ID; 2989, 3017)

Synonym

Conochilus leptopus Forbes, 1893 (ref. ID; 1345, 3688); Conochilus limneticus Stenroos, 1898 (ref. ID; 1345, 3688)

Descriptions

This species with 1 antenna, representing 2 fused, with a relatively shorter foot, forming colonies of only a few individuals, and common in lake plankton. See descriptions of C. norvegicus. (ref. ID; 1923)
The colonies can be seen with the nacked eye as rounded bodies in fresh and preserved samples. Ventral antennae are fused with groups of cilia at the end. Foot as long as body smooth, and appears ringed in contracted specimens. Colony entirely covered with jelly like substance with cannot be seen sometimes in preserved material. (ref. ID; 2715)
See comments of C. hippocrepis. (ref. ID; 2989, 3017)
A pelagic form living in free-swimming colonies, spherical in shape, of a number of individuals attached to a common centre. (ref. ID; 3208)
Only one antenna on corona. Colonies smaller. Freshwater species, also in estuaries. (ref. ID; 4596)

Measurements

Total length varies up to about 450 um. (ref. ID; 1923)
Total length of individuals about 300 um. (ref. ID; 2317)
Contracted specimens range from 250-310 um. (ref. ID; 2715)
Body length 90-110; length of stalk 80-100; width of body 80-85; width of corona 70-85 um. (ref. ID; 3275)
Length of body 200-400 um. (ref. ID; 4596)