juanpabloavendano's Favorites

Cothurnia species found attached to filamentous algae at the shoreline of marine estuary Gardiner's Bay. Imaged in Nomarski DIC on Olympus BH2 using SPlan 40x objective plus variably phone cropping on Samsung Galaxy S9+. Lorica rotund and tapering basally, 47 um long x 30 um wide. Aperture wide, no neck. Aperture border without cleft or collar. External stalk short and slender with no striations; mesostyle short and broad with longitudinal striae; endostyle short without striations. Zooid cylindrical, 56 um long X 25um wide, extending up to one sixth of its length beyond aperture. Diameter of peristomial lip slightly greater than maximum body width. Macronucleus not well visualized but thought to be short sausage-shaped and lying longitudinally in anterior center of body. CV situated near center of infundibulum which is about one third zooid length. Habitat. Marine found attached to filamentous algae. I could find no matching species in Warren and Paynter 1991.

Cothurnia is a genus of freshwater and marine peritrichs in the family Vaginicolidae. It is characterised by living in a transparent tubular lorica. During the feeding or vegetative phase of its life cycle, Cothurnia attaches to submerged surfaces through a short stalk — mostly on the surfaces of fishes, crustaceans and aquatic plants. It is commonly studied for its epibiotic relationship with the host that it is attached to. The etymology of the genus name Cothurnia derives from the ancient Greek word κόθορνος (kóthornos), and from the Latin word cothurnus, meaning "buskin, or high boot". Cothurnia has been noted for its correlation with water quality (especially in water treatment plants). It has been observed a decrease in the prevalence of Cothurnia on prawns as the water quality deteriorates, making it a good indicator of the quality of water in the environment. Cothurnia is often confused with Vaginicola due to their similar morphologies. Vaginicola lacks a stalk and the zooid is attached directly to the lorica.

Cothurnia is mostly sessile, particularly when feeding or asexual reproduction. However, it can be motile when its habitat is disturbed or to search for a habitat with a higher abundance of food. Its mobile stage is called a telotroch and is often mouthless. The cilia of the organism are located on the peristomal disc of the zooid. When feeding, the zooid slowly extends out of its lorica and rhythmically beats its oral cilia to generate a vortex to draw its prey towards its peristomal lip. A typical species of Cothurnia forms a cylindrical lorica to protect the trumpet-shaped zooid. The lorica may be compressed or elongated along the longitudinal axis, resulting in oblate or prolate forms respectively, or it may be compressed along the transverse axis, resulting in dorso-ventrally compressed forms. The shape of these loricae have traditionally been used to distinguish between species, but since they can vary drastically in size and shape, there has been debates regarding the usefulness of the lorica shape as a taxonomic character. When disturbed, the zooid rapidly retracts into the lorica. There is no specific mechanism of aperture closing of the lorica. Towards the posterior end of the lorica, there is a short and slender endostyle that attaches the zooid to the septum of the lorica and a mesostyle that connects the endostyle to the base of the lorica. The scopula produces a short, non-contractile stalk that protrudes through an aperture at the aboral end of its lorica to affix the organism to surfaces. Some species possess smooth and featureless stalks, while others have transverse folds on the surface of their stalks. The stalk forms a basal disc to attach itself like a suction cup.

A revision of Cothurnia (Ciliophora: Peritrichida) and its morphological relatives. ALAN WARREN & JAN PAYNTER. Bull. Br. Mus. nat. Hist. Zool. 57(1): 17-59 Issued 30 May 1991

Marine Litonotus consistent with Litonotus lamella var. uninucleolata Schewiakoff, 1896 from the intertidal benthos of marine estuary Acabonac Harbor at the Louse Point launching site. This cell measures 103 um in length and has a typical Litonotus-like lanceolate body with a curved beak-like anterior with a subtle neck region and a pointed posterior end. The oral bulge extends to 50% of the cell length accompanied by an indistinct mane-like cilia at the ventral anterior. Extrusomes with a spindle shape in a small group at the anterior ventral surface are present and are scattered throughout the cell including particularly the posterior end of the cell. There is a single central ovoid macronucleus. Green algal food vacuoles accumulate in the posterior half of the cell and there is a subterminal contractile vacuole.

Wilbert and Kahan 1981 describe a population in a hypersaline lake:
"Length 30 to 50 um. The body is flattened in such a way as to produce a convex ventral outline and a sigmoid dorsal outline. The left side is bare and bulges outward; the right side bears 6 rows of cilia. The anterior end is narrowed like a neck, and there is a flattened tail at the caudal end. A distinguishing feature is the radial array of trichocysts in the tail region. The mouth slit is also provided with sturdy trichocysts, and others are scattered in the cytoplasm. A contractile vacuole occupies the posterior end of the rounded part. L. lamella has degeneration forms. Small forms, 40 um in length, sometimes have 3 kineties, whereas individuals as large as 200 um have 10-15 (Kahl 1930-1935). The L. lamella population in Solar Lake uniformly had only one macronucleus. This is unusual, for the macronucleus normally consists of 2 oval parts. But the conjugants observed also had one macronucleus, so that it can be assumed that the single nucleus is not an interphase nucleus. The specimens studied by Penard (1922) also included forms with a single macronucleus. Apart from the nucleus, the ciliate has all the characteristics of L. lamella. For this reason Wilbert & Kahan regard the Solar Lake population as a variety. L. lamella var. uninucleaolata feeds on ciliates" (1). "According to Bick & Kunze (1971), the optimal range is in fresh water. The animals can also tolerate salinity as high as 35 0/00 in thalassogenic brackish water, and up to 3.5 0/00 in althlassogenic water". (1)

Penard 1922, in describing the species, also notes that uninucleate and binucleate forms exist. Translated from Penard 1922 "Body lanceolate, relatively slightly elongated, rounded or pointed behind, partly anterior extended into a very short and indistinct neck, curved on the dorsal side, and provided on the ventral side with a broad and very distinct ciliated crest, but delicate and covered fine eyelashes. The flattened ventral side of the body is traversed along its length by four or five longitudinal furrows, at the bottom of which the cilia originate. Cytoplasm containing here and there trichocysts in fine rods, more numerous and regularly distributed at the extremity posterior. Nucleus either simple and ellipsoidal, or double and represented by two joined spherical masses. A contractile vacuole a little anterior to the posterior end. Very variable length, 35 to 100 um " (2).

1. https://www.nies.go.jp/chiiki1/protoz/morpho/ciliopho/litonotu.htm#Litonotus%20lamella%20var.%20uninucleolata
2. ÉTUDES SUR LES INFUSOIRES D’EAU DOUCE. B. PENARD. GEORG & Cie, éditeurs — GENÈVE — 1922. p.65.