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Class:

Florideophyceae

Genus:

Schizymenia J. Agardh

Species:

Schizymenia dubyi

Authority:

(Chauv. ex Duby) J.Agardh

Description:

Erect leaf-like flat fronds, brow-red (liver-coloured), trasnlucent, gradually widening from the base, simple or irregularly split or lobed, then at a narrow angle, overlapping; often noticeably sickle-shaped, with smooth margin, not proliferating texture soft-slippery; cystocarps very small and sunken; very short stunted stipe, small discoid holdfast (Braune & Guiry, 2011).

Original publication: Agardh, J.G. (1851). Species genera et ordines algarum, seu descriptiones succinctae specierum, generum et ordinum, quibus algarum regnum constituitur. Volumen secundum: algas florideas complectens. Part 1. pp. [ii*-iii*], [i]-xii, [1]-336 + 337-351 [Addenda and Indices]. Lundae [Lund]: C.W.K. Gleerup.

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Key characteristics: Fleshy frond, lack of lobing and, generally, marginal proliferations; when dried onto paper the fertile fronds feel like fine sandpaper to the the touch.

Similar species: Dilsea carnosa is much thicker, commoner, and more cartilaginous, has rounded-spathulate blades, and several blades arise from a relatively large basal disk; Halarachnion ligulatum is thin and filmy, never fleshy;Kallymenia reniformis is commoner in the subtidal generally lobed and the lobes are frequently kidney-shaped.

Biogeography

NE Atlantic (Iceland to Marocoo); Mediterranean; NW Pacific (Japan, China, Korea); Australia.

Life Cycle

Gametophytes: soft and fleshy, brownish-red fronds, 500 mm long, 250 mm broad, irregularly split or lobed, rarely proliferous, with a very short (2-3 mm) stipe from a minute attachment disc. Tetrasporophyte (Haematocelis-phase): thick fleshy crust; difficult to identify and rarely reported.

References

Ardré, F. (1980). Observations sur le cycle de développement du Schizymenia dubyi (Rhodophycée, Gigartinale) en culture, et remarques sur certains genres de Némastomacées. Cryptogamie, Algologie 1: 111-140.

Braune, W. (2008). Meeresalgen. Ein Farbbildführer zu den verbreiteten benthischen Grün- Braun- und Rotalgen der Weltmeere. pp. [1]-596, 266 pls. Ruggell: A.R.G. Gantner Verlag.

Silva, P.C., Basson, P.W. & Moe, R.L. (1996). Catalogue of the benthic marine algae of the Indian Ocean. University of California Publications in Botany 79: 1-1259.

Womersley, H.B.S. & Kraft, G.T. (1994). Family Nemastomataceae Schmitz 1892:2, nom. cons.. In: The marine benthic flora of southern Australia. Part IIIA. Bangiophyceae and Florideophyceae (Acrochaetiales, Nemaliales, Gelidiales, Hildenbrandiales and Gigartinales sensu lato). (Womersley, H.B.S. Eds), pp. 270-285. Canberra: Australian Biological Resources Study.

Bourgougnon N, Roussakis C, Kornprobst JM, Lahaye M (1994). Effects in vitro of sulphated polysaccharide from Schizymenia dubyi (Rhodophyta, Gigartinales) on a non-small-cell bronchopulmonary carcinoma line (NSCLC-N6). Cancer Lett. 85: 87-92.

Bourgougnon N, Lahaye M, Chermann JC, Kornprobst JM (1993). Composition and antiviral activities of a sulphated polysaccharide from Schizymenia dubyi (Rhodophyta, Gigartinales). Bioorgan. Med. Chem. Lett. 3: 1141-1146.

Habitat:

Pools and on rock mid lower intertidal zone.

Type information:

Type species: This is the type species (holotype) of the genus Schizymenia.

Basionym: Halymenia dubyi Chauvin ex Duby

Type locality: Cherbourg, Manche, France (Silva, Basson & Moe 1996: 323). Lectotype: STR (Womersley & Kraft 1994: 280).