Euendolithic shell-boring cyanobacteria and chlorophytes from the saline lagoon Ahivadolimni on Milos Island, Greece

Abstract

Samples of typical estuarine mollusc shells (Cerastoderma glauca, Abra ovata and Hydrobia acuta), differing in appearance, size and age, were collected from littoral habitats of a saline water lagoon (Ahivadolimni on Milos Island, Greece). Each shell sample was examined for the distribution, frequency and taxonomy of its shell-boring cyanobacteria and chlorophytes, and the associated attached (epizoic) diatoms. The euendolithic microflora was extracted using Pereny's solution and observed by light microscopy (LM). The results of microbial penetration (traces of euendoliths) were examined by scanning electron microscopy (SEM) after a hypochlorite treatment. The three-dimensional patterns of microbial penetration (boring patterns) were investigated under SEM by applying the resin-casting technique for modern euendoliths. Of the five euendolithic cyanobacteria found, one (Cyanosaccus atticus) was established from Greek marine biotopes, three (Hyella caespitosa var. arbuscula, H. inconstans and H. reptans) are second records and new for Europe, whereas one cyanobacterium (Leptolyngbya terebrans ¼ Plectonema terebrans) and the three euendolithic chlorophytes found (Phaeophila dendroides, Ostreobium quekettii and Gomontia polyriza) show a cosmopolitan distribution. A survey of the diatoms found as epizoic on the mollusc shells (30 taxa) shows that most of them are typical representatives of marine to brackish water of coasts and estuarine areas. A systematic account of all euendoliths found in the mollusc shells is given. The morphological variability of the cyanobacterium Hyella inconstans, and of the chlorophytes Ostreobium quekettii and Gomontia polyriza is presented, with extended taxonomic comments for the latter species. The susceptibility of molluscs to infestation, as well as the morphological variability, world distribution and penetration patterns of the euendoliths within the host mollusc shells are also discussed.

New insights into Lithocodium aggregatum Elliott 1956 and Bacinella irregularis Radoičić 1959 (Late Jurassic–Lower Cretaceous): two ulvophycean green algae (?Order Ulotrichales) with a heteromorphic life cycle (epilithic/euendolithic)

“…A Gomontia stage may be present in species of several euendolithic genera such as Collinsiella Setchell and Gardner, Eugomontia Kornmann, Gomontia Bornet, and Flahault and Monostroma Thuret (e.g., Gardner 1903, 1920;O'Kelly et al 2004), but also in non-euendolithic taxa such as Urospora Areschuog or Acrosiphonia Agardh (Kornmann 1959(Kornmann , 1961(Kornmann , 1962Sussmann and DeWreede 2001) and all of the order Ulotrichales (e.g., Guiry and Guiy 2009). The Gomontia stages of these genera are diYcult to distinguish from each other in the Weld, which has created a lot of confusion in the pastas well as taxonomic problems (e.g., Fan 1959;Wilkinson and Burrows 1972;GolubiT et al 1975;Pantazidou et al 2006;Round 1981, p. 241). In some taxa (e.g., Acrosiphonia grandis), the Gomontia stage grows directly into a Wlamentous alga without formation of zoospores (Kornmann 1970).…”

Life-history trait of the Mediterranean keystone species Patella rustica: growth and microbial bioerosion

“…Occurrence of shell-penetrating marine cyanobacteria has been widely reported since the end of the 19th century (Pantazidou et al, 2006;Radtke & Golubić, 2011). In limpets, the high degrees of shell erosion have been reported for Scutellastra granularis and Cellana toreuma (Richardson & Liu, 1994;Vat, 2000).…”

Erratum to: New insights into Lithocodium aggregatum Elliott 1956 and Bacinella irregularis Radoičić 1959 (Late Jurassic–Lower Cretaceous): two ulvophycean green algae (?Order Ulotrichales) with a heteromorphic life cycle (epilithic/euendolithic)

“…A Gomontia stage may be present in spe-cies of several euendolithic genera such as Collinsiella Setchell and Gardner, Eugomontia Kornmann, Gomontia Bornet, and Flahault and Monostroma Thuret (e.g., Gardner 1903, 1920;O'Kelly et al 2004), but also in non-euendolithic taxa such as Urospora Areschuog or Acrosiphonia Agardh (Kornmann 1959(Kornmann , 1961(Kornmann , 1962Sussmann and DeWreede 2001) and all of the order Ulotrichales (e.g., Guiry and Guiy 2009). The Gomontia stages of these genera are diYcult to distinguish from each other in the Weld, which has created a lot of confusion in the past as well as taxonomic problems (e.g., Fan 1959;Wilkinson and Burrows 1972;GolubiT et al 1975;Pantazidou et al 2006;Round 1981, p. 241). In some taxa (e.g., Acrosiphonia grandis), the Gomontia stage grows directly into a Wlamentous alga without formation of zoospores (Kornmann 1970).…”