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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Conochiloides

Conochiloides Hlava, 1904

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

See Conochilus

ref. ID; 1663

Solitary or colonial. With one or two ventral antennae below the corona. With a ventral gap in the ciliary wreath. Mouth on the corona, nearer the dorsal edge. Gelatinous sheath. Limnetic species. (ref. ID; 1663)

ref. ID; 1923

Lateral antennae elongate, close together on ventral surface of body, or fused for part of length. Ordinarily solitary, but young may attach to tube of mother, forming small groups. (ref. ID; 1923)

ref. ID; 3050

With lateral elongate antennae which are close to each other on the ventral surface of the body or are fused for a part of their length. Solitary forms but the young may attach to the tube of the mother thus forming small colonies. This genus has four species viz. C. coenobasis Skorikov 1904, C. natans (Seligo) 1900, C. dossuarius (Hudson) 1885, and C. exiguus Ahlstrom 1938. According to Edmondson in Ward and Whipple (1959), the four species can be distinguished from each other by the pattern of their antennae. In C. coenbasis the two antennae fuse by their bases and the fused cylindrical part is inserted in the body. In C. natans the two antennae are thin and rod like and the fused part is extremely small. In C. dossuarius the two antennae are free and ununited for almost half their lengths and the fused portion is very similar to that of C. coenobasis. In C. exiguus the two antennae are very small and their fusion is almost complete. There are also differences in the mastax of these four species. In C. coenobasis the uncus is represented by three teeth; in C. natans by five; in C. dossuarius by five only on the right and in C. exiguus by four on the right. (ref. ID; 3050)
  1. Conochiloides coenobasis Skorikov, 1914 (ref. ID; 1345, 1346, 1923, 2261, 2283, 2393, 3083, 3231, 3514) reported year? (ref. ID; 2619, 3029, 3453) Skorikow, 1914 (ref. ID; 3114, 3688) or Scoricoff, 1914 (ref. ID; 2207) reported author and year? (ref. ID; 1519, 3071 male, 5389)

    Quote from ref. ID; 2261

    Quote from ref. ID; 3114

    Quote from ref. ID; 3071

    See; Conochilus coenobasis (ref. ID; 2757), Conochiloides dossuarius (ref. ID; 3231)
  2. Conochiloides deltaicus Rodewald-Rudescu, 1960 (ref. ID; 2627 original paper) or Rudescu, 1960 (ref. ID; 3688)
  3. Conochiloides dossuarius (Hudson, 1885) (ref. ID; 1345, 1346, 1923, 2619, 2715, 2812, 3180, 3514, 3591, 3688) reported year? (ref. ID; 3029, 3231)
    See; Conochilus dorssuarius (ref. ID; 2757)
    Syn; Cephalosiphon dossuarius Hudson, 1886 (ref. ID; 1345, 3688); Conochilioides coenobasis Skorikov, 1914 (ref. ID; 3231); Conochiloides dossuarius Hlava, 1904 (ref. ID; 1345, 3688); Conochilus dossuarius Hudson, 1885 (ref. ID; 1346, 3514) or Hudson & Gosse, 1885 (ref. ID; 3688)
  4. Conochiloides dossuarius var. astosus Arora, 1962 (ref. ID; 3050 original paper)
  5. Conochiloides exiguus Ahlstrom, 1938 (ref. ID; 1345, 1923, 2619)
  6. Conochiloides natans (ref. ID; 1519)
  7. Conochiloides natans Hlava, 1904
    See; Conochiloides natans (Seligo, 1900) (ref. ID; 1345)
  8. Conochiloides natans (Seligo, 1900) (ref. ID; 1345, 1346, 1804, 1923, 2207, 2317, 2715, 3591, 3688) reported year? (ref. ID; 3029, 3046)
    See; Conochilus natans (Seligo, 1900) (ref. ID; 2757)
    Syn; Conochiloides natans Hlava, 1904 (ref. ID; 1345, 3688); Conochilus natans Voigt, 1902 (ref. ID; 3688) or 1904 (ref. ID; 1346); Tubicolaria natans Seligo, 1900 (ref. ID; 1345, 2317, 3688)

Conochiloides coenobasis Skorikov, 1914 (ref. ID; 1345, 1346, 1923, 2261, 2283, 2393, 3083, 3231, 3514) reported year? (ref. ID; 2619, 3029, 3453) Skorikow, 1914 (ref. ID; 3114, 3688) or Scoricoff, 1914 (ref. ID; 2207) reported author and year? (ref. ID; 1519, 3071 male, 5389)

See

Conochilus coenobasis (ref. ID; 2757), Conochiloides dossuarius (ref. ID; 3231)

Descriptions

Ventral antenna prominent. (ref. ID; 2283)

This species is closely related to Conochiloides natans (Seligo), but the ventral feelers rise from the mound-like expansion; the basal portion and the feelers are almost equal in length. The foot is short and almost entirely contracted when fixed. (ref. ID; 2393)

Measurements

Total length 160 µm. (ref. ID; 2283)

Body length 110-115; highest part 70-87; foot 72 (contracted); lateral antennae 25-29x10-12 µm. (ref. ID; 3083)

Conochiloides dossuarius (Hudson, 1885) (ref. ID; 1345, 1346, 1923, 2619, 2715, 2812, 3180, 3514, 3591, 3688) reported year? (ref. ID; 3029, 3231)

See

Conochilus dorssuarius (ref. ID; 2757)

Synonym

Cephalosiphon dossuarius Hudson, 1886 (ref. ID; 1345, 3688); Conochilioides coenobasis Skorikov, 1914 (ref. ID; 3231); Conochiloides dossuarius Hlava, 1904 (ref. ID; 1345, 3688); Conochilus dossuarius Hudson, 1885 (ref. ID; 1346, 3514) or Hudson & Gosse, 1885 (ref. ID; 3688)

Descriptions

The body vase shaped. Foot appears like a stalk and ringed in contracted specimens. Not colonial. Ventral antennae fused at the proximal end to about one-third the length and free at the distal end. Eggs were attached to some specimens by means of jelly-like substance. (ref. ID; 2715)

Body vase-shaped. Not colonial. Ventral antennae fused at the proximal end to about one-third the length and free and the distal end. Foot appearing like a stalk and ringed in contracted specimens. (ref. ID; 3180)

Comments

According to Voigt (1956-1957) these two species differ in two ways: (1) In C. coenobasis the ventral antennae arise from a "mound-like basal portion" (Ahlstrom, 1938) but are separate in their total length. In C. dossuarius, on the other hand, the antennae are jointed proximally, while the basal mound is lacking. (2) In C. coenobasis each uncus has three large teeth, while in C. dossuarius the right uncus has five such teeth, the left uncus three. One of the teeth of the left uncus is divided into three branches, however. That these circumstances are not so unassailable as to justify the maintenance of two separate species can be shown in several ways. Regarding point 1) it must be remembered that the only two authors to have studied "C. coenobasis" intensively, viz. Skorikov (1914) and Ahlstrom (op. cit.), probably both examined the form exclusively in preserved material. (Ahlstrom states as much about his investigation on p.88. Skorikov's paper was unfortunately not available to me). The position regarding my own material is, at all events, that when alive the animals agree exactly with the drawing of a living specimens of C. dossuarius in Hlava (1908), while preserved specimens from the same samples resemble the picture in Ahlstrom (op. cit). This is also true of the ventral antennae, as their common basal part is contracted by preservation and forms the "mound-like portion" mentioned by Ahlstrom. According to Ahlstrom, Skorikov does not discuss the mastax of his form. Nor is the mastax of C. dossuarius dealt with by any previous author (e.g. neither by Hudson & Gosse 1886 nor by Hlava). Ahlstrom is thus the first to study this organ in the rotifers concerned, and he identifies his American form with "C. coenobaisis" solely on the basis of the ventral antennae, an unreliable character, as has been shown above. Concerning the mastax of "C. coenobasis" Ahlstrom does not mention how many individuals he has studied. The same is true of Myers' material of C. dossuarius reported in Ahlstrom's paper. What the asymmetrical conditions in C. dossuarius actually suggest is the existence of individual variation in this respect. A suspicion further strengthened by the drawing (of "C. dossuarius") in Rudescu (1960), where both unci possess three teeth, the hindmost of which is divided into three branches. It is thus evident that neither the ventral antennae nor the mastax justify a holding apart of the two species concerned. (ref. ID; 3231)

Conochiloides dossuarius var. astosus Arora, 1962 (ref. ID; 3050 original paper)

Descriptions

The form in may collection resembles C. dossuarius so far as its mastax is concerned but differs from it in its antennae, one of the two being bifid at its tip. There is also a complete absence of setae on the extremities of the antennae. Because of this difference I think that the form in my collection represent a new variety. (ref. ID; 3050)

Measurements

Maximum length of body 160; maximum breadth of the body 86 µm. (ref. ID; 3050)

Conochiloides natans (Seligo, 1900) (ref. ID; 1345, 1346, 1804, 1923, 2207, 2317, 2715, 3591, 3688) reported year? (ref. ID; 3029, 3046)

See

Conochilus natans (Seligo, 1900) (ref. ID; 2757)

Synonym

Conochiloides natans Hlava, 1904 (ref. ID; 1345, 3688); Conochilus natans Voigt, 1902 (ref. ID; 3688) or 1904 (ref. ID; 1346); Tubicolaria natans Seligo, 1900 (ref. ID; 1345, 2317, 3688)

Descriptions

Forms not colonical. Body vase-shaped; foot stalk like, surrounded by a gelatinous sheath. Ventral antennae free from their proximal end. (ref. ID; 1804)

Contracted specimens looks more or less like C. dossuarius. Ventral antennae are not fused and are free from proximal end. Cilia present terminally. Not colonial. (ref. ID; 2715)

Measurements

Total length 320; maximum width 120 µm. (ref. ID; 1804)

Total length about 300 µm. (ref. ID; 2317)