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Order Cladophorales

Family Cladophoraceae

Cladophora Kützing

Thalli uniseriate, filamentous, sparsely to profusely branched. Growth apical and /or intercalary. Cells multinucleate, chloroplasts parietal, either united in a network or discoid and densely packed. Life history with isomorphic generations: biflagellate gametes and quadriflagellate zoospores produced in little-modified cells, usually terminal on branches.

Cladophora is a large, cosmopolitan genus with species occurring in marine, brackish and freshwater habitats. Morphological characters used to distinguish species include thallus organisation and branching patterns, and cell sizes. Because some of these characters are affected by environment, identification of species can be difficult. Some 195 species of Cladophora are currently recognised worldwide (Guiry, M.D. in Guiry & Guiry 2017), and we have records of 9 species from the South Coast, as well as a further 3 uncertain records (noted but not described here).

Note on Willeella ordinata (ex. Cladophora ordinata). A recent molecular and morphological study of the Cladophoraceae (Boedeker et al. 2016) resurrected several genera, including Willeella, which includes W. ordinata, a species formerly placed in Cladophora and found on the south coast. W. ordinata differs from our Cladophora species by having a distinct oppositely pinnate branching pattern that imparts a feather- or fan-like appearance, especially to the distal part of the thallus.

Uncertain records:

Cladophora feredayi Harvey

Not recorded by Leliaert & Coppejans (2003) or Silva et al (1996) and our specimens (EC 439 East London , T 171 Hluleka) do not match Harvey’s type illustration (which shows a markedly fastigiate thallus) or the description and illustrations in Womersley (1984). One of our specimens is similar to Cladophora sp 1 indet of Leliaert & Coppejans (2003), but without more material, we cannot be sure.

Cladophora subsimplex Kützing

Our only tentative records for this species are microscope slides: one “cf” from Three Sisters (near Port Alfred) and one from Tsitsikamma. It is not recorded by Leliaert & Coppejans (2003), or by Silva et al. (1996) for South Africa, or for Africa by Guiry & Guiry (2012, AlgaeBase). Without more material, we cannot confirm its occurrence on our coast. 

Cladophora afra Kützing

Note: This species, recorded from the “Mouth of Knysna River” and described by Kützing , appears not to have been recorded or recognised since. Without illustrations, a more detailed description or examination of the type, it is not possible to relate it to some of the unidentified specimens available. Based on the information in Kützing (1849) and Barton (1893), Leliaert & Coppejans (2003; Table 1) note only that the habit is “free erect, flaccid filaments”, “filaments often curved”, “branching spreading, pseudodichotomous” and the apical cells are 20-30 µm wide and basal cells 70-90 µm wide.

Key to species of Cladophora 

1a. Cells, at least in proximate parts of thallus, longer than 10 mm

2

1b. Cells shorter than 5 mm

3

2a. Proximal end of basal cell and proximal cells of main axes with annular constrictions

C. rugulosa

2b. Basal cells of erect axes much longer than cells above, proximal cells of erect axes usually thickened distally

C. radiosa

3a. Apical cells more than 90 µm in diameter

C. lehmanniana

3b. Apical cells less than 80 µm in diameter

4

4a. End branches of axes with short secund branchlets

C. sericea

4b. Branching not secund, or if secund branches present, branches not short

5

5a. Branching restricted to proximal parts of thallus

C. flagelliformis

5b. Branching not restricted to proximal parts of thallus

6

6a. Thalli forming mats of interwoven filaments with stoloniferous bases, uprights branched or unbranched

C. coelothrix

6b. Thalli forming tufts or cushions but without stoloniferous bases

7

7a. Apical cells tapering, young branchlets straight or almost straight

C. sp II

7b. Apical cells not tapering, young branchlets usually curved

8

8a. Plants forming dense flaccid tufts up to 5 cm tall, lateral usually shorter than main axes, 1-2 (-3) laterals per parent cell

C. albida

8b. Plants forming dark green cushions up to 5 mm tall, laterals frequently same length as main axes, usually a maximum of one branch per parent cell

C. sp I

 

References Cladophora:

Barton, E.S. 1893. A provisional list of the marine algae of the Cape of Good Hope. Journal of Botany, London, 31: 53-56,81-84, 110-114, 138-144, 171-177, 202-210.

Boedeker, C., Leliaert, F & G.C. Zuccarello. 2016. Molecular phylogeny of the Cladophoraceae (Cladophorales, Ulvophyceae), with the resurrection of Acrocladus Näegeli and Willeella Børgesen, and the description of Lurbica gen.nov. and Pseudorhizoclonium gen.nov. Journal of Phycology 52: 905-928.

Kützing, F.T. 1849. Species algarum. pp. [i]-vi, [1]-922. Lipsiae [Leipzig]: F.A. Brockhaus.

Leliaert, F. and E.Coppejans. 2003. The marine species of Cladophora (Chlorophyta) from the South African east coast. Nova Hedwigia 76: 48-52.

Guiry, M.D. in Guiry, M.D. & Guiry, G.M. 2017. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 17 May 2017.

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.

Stegenga, H., Bolton, J.J. and R. J. Anderson. 1997. Seaweeds of the South African west coast. Contributions from the Bolus Herbarium 18: 655 pp.

Womersley, H.B.S. 1984. The marine benthic flora of southern Australia. Part I. pp. 329, 102 figs, 16 plates. Adelaide: Government Printer, South Australia.

 

Cite this record as:

Anderson RJ, Stegenga H, Bolton JJ. 2016. Seaweeds of the South African South Coast.
World Wide Web electronic publication, University of Cape Town, http://southafrseaweeds.uct.ac.za; Accessed on 21 November 2018.