Ichthyodontum A.M.Scott & G.W.Prescott, 1956

Holotype species: Ichthyodontum sachlanii A.M.Scott & Prescott

Original publication and holotype designation: Scott, A.M. & Prescott, G.W. (1956). Notes on Indonesian freshwater algae, II. Ichthyodontum, a new desmid genus from Sumatra. Reinwardtia 4(1): 105-112, 7 figs.

Description: Cells medium sized (132-150 um long), solitary, elongate-cylindric, with length 6-7 times width. Semicells straight or curved, slightly broader at base, truncate at apex. Morphology of semicell apices commonly differs on same cell, although two different types of cells, each having similar apical morphology on the two semicells, known to occur. One apical form ( fishtail ) with prominent median notch and short, axially directed spine on each apical angle; other apical form with shallow median depression and short, laterally directed spine on each apical angle. Semicells with fishtail apex strongly curved, whereas semicells with second apical type almost straight. A pair of large, horizontally disposed mucilage pores present just below apical notch or depression. Semicell base slightly oval in transverse section with 10 poorly developed, longitudinally oriented folds, each of which extends over isthmus constriction as a broad, blunt, thick-walled tooth. These basal teeth interdigitate (but do not interlock) with similar teeth on base of other semicell. Chloroplast morphology uncertain, but probably a plate or ribbon with axial row of 5-6 pyrenoids. Asexual reproduction not studied but cell division and new semicell morphogenesis typical of Cosmarium-type desmids assumed (see Cosmarium). At type locality, 88 % of cells were dichotypical (semicells dissimilar); this predominance of asymmetric cells must result from differing morphogenetic pattern following cytokinesis. Sexual reproduction unknown. Ichthyodontium occurs in Sumatra and Northern Australia. Type locality a swamp in southern Sumatra, pH ca. 6.0; in plankton sample and among periphyton squeezed from aquatic vascular plants.

Information contributed by: J.F. Gerrath. The most recent alteration to this page was made on 2013-09-12 by M.D. Guiry.

Taxonomic status: This name is of an entity that is currently accepted taxonomically.

Most recent taxonomic treatment adopted: Guiry, M.D. (2013). Taxonomy and nomenclature of the Conjugatophyceae (=Zygnematophyceae). Algae. An International Journal of Algal Research 28: 1-29.

Verification of Data
Users are responsible for verifying the accuracy of information before use, as noted on the website Content page.

Contributors
Some of the descriptions included in AlgaeBase were originally from the unpublished Encyclopedia of Algal Genera, organised in the 1990s by Dr Bruce Parker on behalf of the Phycological Society of America (PSA) and intended to be published in CD format. These AlgaeBase descriptions are now being continually updated, and each current contributor is identified above. The PSA and AlgaeBase warmly acknowledge the generosity of all past and present contributors and particularly the work of Dr Parker.

Descriptions of chrysophyte genera were subsequently published in J. Kristiansen & H.R. Preisig (eds.). 2001. Encyclopedia of Chrysophyte Genera. Bibliotheca Phycologica 110: 1-260.

Linking to this page: https://www.algaebase.org/search/genus/detail/?genus_id=43535

Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 12 September 2013. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 23 April 2024