Bryozoa on disarticulated bivalve shells from Todos os Santos Bay, northeastern Brazil, with the description of two new species

As sessile organisms, bryozoans are among the commonest components of the encrusting communities on hard substrata. On unconsolidated bottoms, benthic animals and their carapaces, including mollusk shells, represent potential surfaces for encrustation. Here we describe the bryozoan fauna growing on disarticulated bivalve shells collected intertidally on Itaparica beach, Todos os Santos Bay, northeast Brazil. We examined a total of 382 valves representing seven species of bivalves, among which we found 82 valves of three bivalve species to be encrusted by bryozoans, with 109 bryozoan colonies detected overall. We identified 11 cheilostome bryozoan species, among which Phidoloporidae and Smittinidae were the most diverse, with four and two species, respectively. We redescribed two bryozoan species, Parasmittina loxoides and Rhynchozoon phrynoglossum, and describe another two, Pleurocodonellina marcusi n. sp. and Rhynchozoon itaparicaensis n. sp., as new. A new combination for Cribella triangulata Canu & Bassler, 1928 is proposed, including Calyptotheca tenuata Harmer, 1957 as a new junior subjective synonym of Calyptotheca triangulata n. comb. All but one of the 11 species have encrusting colonies; Licornia aff. diadema, forms erect branching colonies. For seven of the bryozoans, ours are the first records of these species growing on shells. Although the majority of bryozoans we studied have also been reported on other substrata, Rhynchozoon brasiliensis and Parasmittina loxoides were predominant in the fauna, comprising 79 (72%) of all colonies inventoried. Due to the lack of information on the distribution of these species in northeastern Brazil, further studies are needed to determine whether they show any substratum preference.

Revision of the Verrucaria elaeomelaena species complex and morphologically similar freshwater lichens (Verrucariaceae, Ascomycota)

The freshwater lichens Verrucaria elaeomelaena, V. alpicola, and V. funckii (Verrucariaceae/Ascomycota) have long been confused with V. margacea and V. placida and conclusions on the substratum preference and distribution have been obscured due to misidentifications. Independent phylogenetic analyses of a multigene dataset (RPB1, mtSSU, nuLSU) and an ITS-dataset combined with morphological and ecological characters confirm that the Verrucaria elaeomelaena agg. consists of several cryptic taxa. It includes V. elaeomelaena s.str. with mostly grey to mid-brown thalli and transparent exciple base which cannot be distinguished morphologically from several other unnamed clades from low elevations, the semi-cryptic V. humida spec. nov., which is characterised by smaller perithecia, shorter and more elongated spores compared to other species in this group and V. alpicola with specimens mostly from high elevations, dark brown to black thalli, a brown exciple base and large ascospores. While Verrucaria funckii is confirmed to be restricted to siliceous substrata, limestone and siliceous substrata are both colonised by V. elaeomelaena s.str. as well as by representatives of various other clades. The substratum type cannot be seen as a diagnostic character for taxa within this species group. The taxa included in Verrucaria elaeomelaena agg. are closely related to V. submersella and together with V. funckii they form a sister clade to the “Endocarpon-group” in the Verrucariaceae. Verrucaria margacea is superficially similar to some specimens of V. elaeomelaena agg. It is nested within an unresolved larger clade with Dermatocarpon, the subclades of the Endocarpon- and the V. elaeomelaena-group. Verrucaria margacea can be distinguished from most of the specimens in the V. elaeomelaena group by its generally non subgelatinous thallus, often with distinct cracks, narrowly ellipsoidal ascospores and the general absence of a black basal layer or dark pigments in the exciple base. The form and size of the ascospores distinguish V. placida from most specimens in the V. elaeomelaena complex, but there is overlap with some forms of V. alpicola. Epitypes are proposed for V. elaeomelaena, V. alpicola and V. margacea and a European key to the species of subgelatinous freshwater Verrucaria with spreading involucrellum and large ascospores is provided.

Molecular data support Ramalina ovalis as a distinct lineage (Ramalinaceae, Ascomycota)

Ramalina celastri is a highly variable, widely distributed pan-subtropical lichen species. In Australasia the species had been separated into two subspecies; R. celastri subsp. celastri and R. celastri subsp. ovalis. This study compares morphological variation, substratum preference and sequences of the internal transcribed spacer (ITS) and intergenic spacer (IGS) regions of ribosomal DNA from a range of specimens from New Zealand and one from Australia. Bayesian and ML trees generated using the sequence data form two well-supported clades corresponding to the two previously recognized subspecies. Molecular, morphological and geographical differences support the recognition of R. ovalis at the species rank.