The genus Ephydatia (Spongillina: Spongillidae) in Africa: a case of Mediterranean vs. southern Africa disjunct distribution

Abstract

Biogeographia vol. XXIX — 2008 (Pubb/icato i/ 30 dicembre 2008) The Mediterranean—southern African disjunct distribution pattern The genus Ep/vydtztzkz (Spongillina: Spongillidae) in Africa: a case of Mediterranean VS. southern Africa disjunct distribution RENATA MAN CONI Dz'])zzrz‘z'mmz‘o (Ii Zoologirz e Gmeriaz Evoluzionisticzz, Unit/ersitiz di Srlssrzri, via Muroni 25, 07100 Samzri, Italy; 6‘-mzzils r. mrz72mm'@um'5:. it Key words: biodiversity, biogeography, Africa, Mediterranean vs. Southern Africa disjunct distribution SUMMARY A synthesis on the taxonomy, geographic distribution and ecology of the genus Ep/Jydzztizz in Africa is reported and discussed. This genus is characterised, in the context of the present biogeographic patterns ofAfrican freshwater sponges, by a peculiar clisjunct distribution in the Pztlaearctic Africa and Southern Africa with a large gap from Sahara to Namibia, South Africa and southern Mozambique. The bipolar pattern is consistent with a model of Mediterra.nean—southern African disjunction with intermediate isolated enclaves in highlands of eastern Africa. SPONGE DIVERSITY IN AFRICAN INLAND WATER The highest taxonomic richness of Spongillina (Porifera: Demospongiae: Haplosclerida) at the biogeographic scale is recorded from the Neotropical (63 species), Palaearctic (59 species) and Afrotropical (49 species) regions, while lower values are known in the Oriental (37 species), Australasian (33 species), Nearctic (32 species) and Oceanic Pacific Islands (5 species) (Manconi and Pronzato, 2002, 2005, 2008ab; Pronzato and Manconi, 2002). At the continental scale the African Spongillina comprises 17 genera and 57 species belonging to 4 families, namely Malawispongiidae (2 genera, 2 spe— cies), Metaniidae (1 genus, 1 species), Potamolepidae (4 genera, 17 species), Spongillidae (9 genera, 10 species) and 1 incertae Jedi; genus (1 species) (Weltner, 1913; Arndt, 1936; Penney and Racek, 1968; Benerescu, 1995; de Silva and Volkmer-Ribeiro, 1998, 2001; Manconi et al., 1999, 2008; Manconi and Pronzato, 2002, 2004, 2008ab, 2009). Most species (75.8 %) are exclu- sive to this continent and a notable value ofendemicity 5.5. at the species (39.6 %) and genus level (35 %) characterises the Afrotropical region, even though