Marine benthic algae of Namibia

Abstract

SUMMARY: The first comprehensive study of the marine algal flora of Namibia including descriptions and illustrations of most species is presented. The main objective of this work is to report a flora that, until now, has scarcely been studied. The work compiles all the available information on the marine benthic flora of Namibia and provides new data about it composition and biogeography, as well as detailed descriptions and remarks of most of its species. The samples on which this study is based were collected between 1986 and 1989 in the eulittoral and the upper sublittoral zones of the north half of the Namibian coast. According to the present data, the marine benthic flora of Namibia comprises 196 taxa (147 Rhodophyceae, 20 Phaeophyceae, 15 Ulvophyceae, 6 Cladophorophyceae and 8 Bryopsidophyceae), 21 of which has not been recorded from this coasts. This temperate flora is mainly characterized by a low number of species, a low proportion of Phaeophyceae and a high degree of endemism. Concerning the species number, the flora is quite poor due to both the scarce availability of colonizable substratum and the low diversity of habitats. On the other hand, the low proportion of Phaeophyceae is the reason for which the R/P and (R+C)/P ratios take disproportionately high values and so they are not useful in this geographical area. As regards the degree of endemism, the marine benthic flora of Namibia includes quite a high number of taxa endemic to southern Africa (55 taxa; 28.1% of the flora); 25 of these 55 taxa (12.8% of the flora) are endemic to the biogeographic Benguela Marine Province and only Acrosorium cincinnatum is endemic to the Namibian coasts.Key words: Namibia, marine algae, morphology and anatomy, distribution, biogeography, taxonomy, check-list. RESUMEN: ALGAS BENTÓNICAS MARINAS DE NAMIBIA. -Este trabajo recoge toda la información existente hasta el momento sobre la flora bentónica marina de Namibia y proporciona nuevos datos sobre su composición y biogeografía, además de descripciones detalladas y valoraciones críticas de muchas de sus especies. El trabajo se ha realizado a partir de muestras florísticas recolectadas entre los años 1986 y 1989 en las zonas eulitoral y sublitoral superior de la costa de la mitad norte del país, entre Walvis Bay y la desembocadura del río Kunene. Según los datos actuales, la flora bentónica marina de Namibia está representada por 196 táxones (147 Rhodophyceae, 20 Phaeophyceae, 15 Ulvophyceae, 6 Cladophorophyceae y 8 Bryopsidophyceae), 21 de los cuales no habían sido citados hasta el momento de las costas de este país. Se trata de una flora de carácter templado que se caracteriza principalmente por el bajo número de especies, la escasa proporción de feofíceas y el elevado grado de endemismo. En cuanto al número de especies, la flora de Namibia es relativamente pobre, debido a la escasa disponibilidad de substrato colonizable y a la baja diversidad de hábitats. Por otra parte, la baja proporción de feofí-ceas hace que los índices R/P y (R+C)/P adopten valores desproporc...

Morphology and molecular study of Pterosiphonia arenosa sp. nov. (Rhodomelaceae, Rhodophyta) from Jeju Island, Korea

“…The distant relationships of P. arenosa and P. pennata from the putative relatives raise questions about divergence pathways, which will be reinvestigated through additional taxon sampling within the genus. Moreover our results also clarify the distinction between P. cloiophylla from South Africa and P. complanata from Europe (2.2% of sequence divergence), for which the synonymy have been previously suggested (Rull Lluch 2002). Differences between Pterosiphonia and Symphyocladia have been said to be slight and insubstantial (Kraft and Wynne 1992).…”

“…Molecular techniques also allow us to answer questions on determining the species without clear-cut morphological diagnostic criteria. This is the case of the genus Pterosiphonia where several synonymies have been suggested due to the species are distinguished solely based on a few vegetative characters, which overlapping in some species (Rull Lluch 2002, Díaz Tapia and Bárbara 2004, 2011, Gabrielson et al 2004.…”

Morphology and systematics of Calliblepharis hypneoides, sp. nov. (Cystocloniaceae, Rhodophyta) from the Atlantic Iberian Peninsula

“…Another collection similar to both H. arbuscula and C. hypneoides was described from Namibia as 'Hypnea sp.' (Rull Lluch, 2002). We have examined these Namibian specimens (BCF-A 1167) and observed that, in addition to the morphological features described by Rull Lluch (2002), they also have refractive inclusions in the outer cortical cells, as in C. hypneoides.…”

Proposal of the Name Chaetomorpha vieillardii (Kütz.), n. Comb., for a Large-Celled Tropical Chaetomorpha (Chlorophyta)

“…are large-celled, attached filaments, the distal cells becoming almost spherical and up to about 2 mm in diameter (Simons 1976) and basal cells 5-12 mm long. This species is restricted to South Africa (Stegenga et al 1997) and Namibia (Rull Lluch 2002). Chaetomorpha moniligera Kjellm., with a distribution restricted to Japan and Korea, is also a species with attached, large-celled filaments.…”