Operculigera haswelli, Clamp & Kane, 2003

Clamp, John C. & Kane, John R., 2003, Redescription of Four Species of Lagenophryid Peritrichs (Ciliophora) from Australia and New Guinea, With Descriptions of Two New Species, Records of the Australian Museum 55 (2), pp. 153-168 : 157-158

Operculigera haswelli n.sp.

Figs. 3–7 , 12 ; Tables 3, 6

Description. Lorica hemispheroidal, suboval in dorsal view, moderately wider than long. Lorica more or less symmetrical in dorsal view; width of right half from midline to edge not noticeably greater than width of left half from midline to edge. Rim of lorica not thickened. Dorsal surface of lorica without curved ridge. Posterior part of vallum reduced to slightly thickened ridge. Anterior and lateral parts of vallum moderately tall; posterior edges of lateral parts sloping abruptly to posterior part of vallum and flaring outward. Free edge of vallum smooth, even, usually with spine on left margin. Spine varying from absent to as long as width of body of vallum. Long strip near base of inner wall of each anterolateral part of vallum moderately thickened and projecting inward to form prominent, protruding fold. Rim of lorica aperture heavily thickened. Operculum subcuneate in dorsal view. Anterior edge of operculum moderately thickened to form narrow, ventral shelf; ventral shelf smooth, lacking processes. Macronucleus elongate, cylindroid, usually folded to make compact mass. Macronucleus located in left half of body. Micronucleus ovoid, almost always located near centre of macronucleus rather than near either end.

Etymology. This species is named in honour of William A. Haswell, who published the first mention of lagenophryid peritrichs on Australian crustaceans in 1901.

Type material. HOLOTYPE, AUSTRALIA, Tasmania, Great Lake ; 1914, W.M. Tattersall; on Mesacanthotelson tasmaniae (Thomson, 1894) , pleopods ( NMNH-CC USNM 60658 ) . Holotype slide with holotype organism marked by inscribed circle (Heidenhain’s hematoxylin), AM P62814 .

PARATYPE slides (Heidenhain’s hematoxylin), AM P62815 and IPTC USNM 1004288 .

Remarks. The spine on the left margin of the vallum of O. haswelli is unique within the genus. Operculigera taura Clamp, 1991 has a long, slender spine on each side of the anterior part of the vallum, but they project anteriad at a very different angle ( Clamp, 1991) to the laterally projecting spine of O. haswelli , the tip of which curves toward the posterior in maximally developed examples ( Fig. 4 ). Operculigera velata Jankowski, 1986 has a single, long, pointed process on the left margin of the vallum, but it is broad and bladelike rather than being a slender spine.

The spine on the vallum was extremely variable in its development among individual ciliates in the single sample of O. haswelli that was examined. Most individuals had a spine of some sort ( Figs. 3–6 , 12 ), but the spine was completely absent in some ( Fig. 7 ). When present, the spine varied from extremely long and acuminate ( Figs. 3, 4 , 12 ) to short, barely visible, blunt processes ( Figs. 5, 6 ).

Figures

Figs.3–7. Operculigera haswelli n.sp. from the type locality and host; Heidenhain’s hematoxylin preparations,AM P62814 and P62815. (3) Dorsal view of holotype individual with maximally developed spine. (4) Vallum with maximally developed spine curving posteriad. (5) Vallum with partially developed spine. (6) Vallum with minimally developed spine reduced to blunt process. (7) Vallum lacking spine.

Figs. 8–13. (8–11) Operculigera montanea from the type locality and host; Erlich’s hematoxylin preparations, AM P62810. (8) Heavily infested pleopod of host at low magnification. Arrow, lateral view showing triangular profile of lorica. (9) Dorsal view of single individual. See Fig. 1 for explanation of symbols. (10) Dorsal view of individual with intracellular parasite (arrow). (11) Dorsal view of individual with empty, ruptured cyst of intracellular parasite (arrow). (12) Dorsal view of Operculigera haswelli n.sp. from the type locality and host; Heidenhain’s hematoxylin preparation, AM P62814. Arrow, spine on left margin of vallum. (13) Dorsal view of two individuals of Operculigera inornata n.sp. from Great Lake, Tasmania; Heidenhain’s hematoxylin preparation, IPTC USNM 1004291. Arrow, intracellular parasite.