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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Lacinularia

Lacinularia Schweigger, 1820

Synonym Megalotrocha Bory de St. Vincent, 1826 in part. (ref. ID; 2978, 3688); Strophosphaera Poggenpol, 1872 (ref. ID; 3688)

ref. ID; 1663

Adults in spherical, sessile colonies attached to aquatic plants. Colonies with adhering gelatinous tubes. Trunk without protuberances. Corona heart-shaped and with the sinus ventral. (ref. ID; 1663)

ref. ID; 1923

Easily distinguishable from Conochilus by the position of antennae, and from Sinantherina by presence of gelatinous matrix. Frequent in hard water. (ref. ID; 1923)

ref. ID; 2737

Colonial Floscularidae forming spherical or ellipsoidal colonies ordinarily of many individuals embedded in a gelatinous matrix. Corona heart- shaped, kidney-shaped or wide egg-shaped. Oviferon or egg-carrier is absent. (ref. ID; 2737)
  1. Lacinularia alboflavicans Cubitt, 1872
    See; Sinantherina socialis (ref. ID; 3688)
  2. Lacinularia elliptica Shephard, 1897 (ref. ID; 2796, 3591, 7846)
  3. Lacinularia elongata Shephard, 1897 (ref. ID; 2757)
  4. Lacinularia flosculosa (O.F. Muller, 1758) (ref. ID; 1345, 1821, 1923, 2737, 2757, 2833, 3688) or 1773 (ref. ID; 3591) reported year? (ref. ID; 3396)
    Syn; Brachionus socialis Pallas, 1766 (ref. ID; 3688); Hydra stentoria Linne, 1758 (ref. ID; 3688); Lacinularia flosculosa Harring, 1913 (ref. ID; 1345, 3688); Lacinularia fluviatilis Carus, 1831 (ref. ID; 1345, 2737, 3688); Lacinularia socialis Ehrenberg, 1830 (ref. ID; 1345, 2737, 2757, 3688); Linza flosculosa Schrank, 1803 (ref. ID; 3688); Megalotrocha socialis Bory de St. Vincent, 1826 (ref. ID; 1345, 2737, 3688); Vorticella flosculosa O.F. Muller, 1773 (ref. ID; 1345, 2737, 3688)
  5. Lacinularia fluviatilis Carus, 1831
    See; Lacinularia flosculosa (ref. ID; 1345, 2737, 3688)
  6. Lacinularia ismaeloviensis (Poggenpol, 1872) (ref. ID; 2757) reported author and year? (ref. ID; 1923), ismailoviensis misspelling? (Poggenpol, 1872) (ref. ID; 3591)
    Syn; Lacinularia natans Western, 1891 (ref. ID; 2757)
  7. Lacinularia ismailoviensis (ref. ID; 1923)
  8. Lacinularia melicerta Ehrenberg, 1832
    See; Floscularia melicerta (ref. ID; 1345, 2810, 3688)
  9. Lacinularia natans Western, 1891
    See; Lacinularia ismaeloviensis (ref. ID; 2757)
  10. Lacinularia pedunculata Hudson, 1889 (ref. ID; 2757)
  11. Lacinularia racemovata Thorpe, 1892 (ref. ID; 2757)
  12. Lacinularia reticulata Anderson & Shephard, 1892 (ref. ID; 2757)
  13. Lacinularia socialis (ref. ID; 1519)
  14. Lacinularia socialis Ehrenberg, 1830
    See; Lacinularia flosculosa (ref. ID; 1345, 2737, 2757, 3688)
  15. Lacinularia striolata Shephard, 1899 (ref. ID; 2757)
  16. Lacinularia volvox Schoch, 1868
    See; Conochilus hippocrepis (ref. ID; 1345, 3688)

Lacinularia flosculosa (O.F. Muller, 1758) (ref. ID; 1345, 1821, 1923, 2737, 2757, 2833, 3688) or 1773 (ref. ID; 3591) reported year? (ref. ID; 3396)

Synonym

Brachionus socialis Pallas, 1766 (ref. ID; 3688); Hydra stentoria Linne, 1758 (ref. ID; 3688); Lacinularia flosculosa Harring, 1913 (ref. ID; 1345, 3688); Lacinularia fluviatilis Carus, 1831 (ref. ID; 1345, 2737, 3688); Lacinularia socialis Ehrenberg, 1830 (ref. ID; 1345, 2737, 2757, 3688); Linza flosculosa Schrank, 1803 (ref. ID; 3688); Megalotrocha socialis Bory de St. Vincent, 1826 (ref. ID; 1345, 2737, 3688); Vorticella flosculosa O.F. Muller, 1773 (ref. ID; 1345, 2737, 3688)

Descriptions

  • Egg: Newly deposited amictic eggs are dark, but they lighten during maturation. Before hatching, red eyespots as well as the ciliated corona and mastax may be distinguished. (ref. ID; 1821)
  • Larvae: Larvae have a long, worm-like body, divided into three regions: head, trunk, and foot. And they possess a circular wreath of relatively short cilia at the terminus of the head and of the foot. At the anterior end are two red eyespots set widely apart. The head is slightly broader than the trunk. Ganglion, a muscular mastax with well-developed trophi, two stomach glands, and a voluminous intestine are easily seen. These forms also possess red eyespots in the head region, but the lobes or arms of the adult animal are already present inserted inside of the head. Also visible is a large infundibulum, a vestibulum, a large mastax, and an intestine. An anus is usually visible, located in the middle part of the trunk. Larvae possess longitudinal hypodermal glands in the trunk. All internal organs usually obscured by abundant glandular inclusions. A dark oval formation which begins to brighten with the development of the larva is present. This body, which is probably identical to the anisotrophic (birefringent) crystalline structure (ACS) described by Wallace (1993), may function as an energy reserve for swimming and metamorphosis until the young animal begins feed. The foot is usually about 1/3 the total length of the body and contains two very prominent cement glands; the terminal part also contains small bladder-like glands. After nearly synchronic hatching of the amictic eggs, the larvae congregate, and after 1.5-2 hours leave the parent colony together as a young colony of up to 60 individuals. This synchronization is not reflected, however, in larval swimming movements which appears to be chaotic. After the larvae attach to a substratum, the corona of the young females develops further, becoming more like that of the adult, except they are slightly smaller. As the foot elongates the gland content of the body decreases. (ref. ID; 1821)
  • Adult: Jelly tubes of each individual flow together into a common matrix. (ref. ID; 1821)

    This species form sessile colonies. It occasionally is found as solitary individual and may be confused with Ptygura. It may also be briefly confused with Octotrocha. (ref. ID; 1923)

    Colonies were observed attached to dead floating twigs and submerged weeds. The individuals, unlike those of a Sinantherinid colony are embedded in a gelatinous matrix. 100-200 individuals constitute a colony. Corona is heart-shaped with pouch-like structure at the inner margin and they are connected with one another by delicate thread-like connections. There is no oviferon present. The specimens in my collection are very smaller. Voigt (1957) mentions that L. flosculosa is 1,500-2,000 µm in length, but the specimens in my collection measure 403-676 µm in length and 117-139 µm in breadth. But I have noticed that many species of Rotifera collected in India otherwise similar to those described from other countries and hence not representing new species, are smaller in size. (ref. ID; 2737)

    Measurements

    Total length 950-1140; egg size 128x98; larval length 270-290 µm. (ref. ID; 1821)