Two new species of the liverwort genus Riccia L. from tropical Africa: R. somaliensis and R. erubescens

Abstract

Two new Riccia species, R. somaliensis and R. erubescens from Africa are described and illustrated. They are both classified in the subgenus Riccia, section Riccia. R. somaliensis has hyaline, somewhat frilly scales and apolar, wingless spores; R. erubescens has shiny dark, purple-red to bright cherry-red scales and polar, winged spores with numerous small areolae; its tissues are sometimes distorted by gelatinous globules that are gradually extruded on the dorsal surface.     

On the identity of Riccia teneriffae S.W.Arnell (Marchantiophyta: Ricciaceae) and a note on R. cavernosa Hoffm. in the Canary Islands

Abstract

We revised both the holotype and an isotype of Riccia teneriffae S.W.Arnell 1962 and additionally revised our own collections of Riccia cavernosa Hoffm. 1795 from the Canary Islands. Since the types of R. teneriffae represent R. cavernosa, and the latter name precedes the former, R. teneriffae should be treated as a synonym of R. cavernosa. In the Canary Islands, R. cavernosa appears to be rare. It has been found on La Gomera, Gran Canaria, Lanzarote, and Tenerife. We report it as new to Fuerteventura. R. cavernosa inhabits ephemeral, thin layers of mud. Very rarely it occurs on basaltic pyroclasts. SEM images of spores are presented. The local distribution is mapped.     

A new Indian species of Riccia L. with connections to northern Australia

Introduction. During a recent explorative field trip to the Western Ghats a new species of Riccia was discovered with possible links to the northern Australian species, Riccia caroliniana Na-Thalang.

Key Results. Morphological similarities between the new species, R. sahyadrica and R. caroliniana include the ventral positioning of the photosynthetic tissue in the ventral section of the thallus in specialised structures known as ventral lamellae. These form a v-shaped patterning along the ventral surface of the thallus and are unique to these two species. Both species also bear similar spores with differences in the micro-ornamentation. Differences between the two species also extend to sexual condition, whereby R. caroliniana is dioicous and R. sahyadrica is monoicous.

Conclusions. A new species, Riccia sahyadrica Manju & Cargill is described and illustrated and compared to the only other morphologically similar species, R. caroliniana endemic to northern Australia. Both species possess the unique characteristic of bearing ventral photosynthetic tissue in contrast to the dorsal position typically seen in all other Riccia species.     

Genetic Diversity of Frankia Microsymbionts from the Relict Species Myrica faya (Ait.) and Myrica rivas-martinezii (S.) in Canary Islands and Hawaii

In the Western Canary Islands, Myrica faya and Myrica rivas-martinezii (Myricaceae) are phylogenetically close, endemic, actinorhizal species presumed to be remnants either of the European or the African Tertiary floras. Unisolated Frankia strains from field-collected nodules on Tenerife, Gomera, and La Palma Islands were compared by their rrs gene and 16S–23S intergenic spacer (IGS) restriction patterns. To compare the genetic diversity of Frankia strains from within and outside the host’s native range, nodules of M. faya field plants were collected both in Canary Islands and in Hawaii, where this species is an exotic invasive. Myrica rivas-martinezii, endemic to the Canary Islands, was sparsely nodulated in the field. Frankia strains harbored in field-collected nodules of M. faya and M. rivas-martinezii belonged to the Elaeagnaceae strains’ genetic cluster and exhibited a high degree of diversity. Frankia genotypes were specific to each host species. In the Canary archipelago, we found no relationship between site of collection and Frankia genotype for M. faya. The only exceptions were strains from site 2 in Tenerife, a location with a geological history different from the other sites sampled. Hawaiian and Canarian M. faya strains had no genotypes in common, raising questions concerning the origin of M. faya-infective Frankia in Hawaii. Nodular strains of M. rivas-martinezii from nursery plants were genetically characterized and shown to be divergent from the strains of field-collected nodules and belong to the Alnus-Casuarina strains cluster. This suggests Myrica may have the potential to nodulate with a broader range of Frankia genotypes under artificial conditions than has been detected in field-collected nodules.     

Xenopsylla spp. (Siphonaptera: Pulicidae) in murid rodents from the Canary Islands: An update

The geographical and host distributions of Xenopsylla fleas parasitizing murid rodents on the Canary Islands have been reported. Three Xenopsylla species, X. cheopis, X. brasiliensis and X. guancha, have been detected on two rodents species, Mus musculus and Rattus rattus. X. guancha has been the most prevalent species detected, specifically on M. musculus, the most abundant rodent, but it has been detected only on three eastern islands, where the species is endemic. X. cheopis has been shown to be the most widely distributed species throughout the archipelago and the species most frequently found on R. rattus. X. brasiliensis has been shown to be the least prevalent Xenopsylla species, with the lowest geographical distribution on the Canary Islands and focused only on R. rattus. The detection of both X. cheopis and X. brasiliensis on the island of Lanzarote, and of X. guancha on the island of Fuerteventura and the islet of La Graciosa represents the first report of these species on those particular Canary Islands.     

Ecophysiology and distribution of the endemic leafless spurgeEuphorbia aphylla and the introducedE. tirucalli (Euphorbiaceae,Euphorbia sect.Tirucalli) in the Canary Islands

The leafless spurgeEuphorbia aphylla (Euphorbiaceae), an endemic species restricted to several of the Canary Islands where it inhabits coastal and arid localities, expresses Crassulacean Acid Metabolism (CAM) when it is subjected to summer drought. A flexible CAM is consistent with the general ecology of the species. It is the only member of sect.Tirucalli native to the Canary Islands and is at the north-western edge of the section's biogeographical range. The other members of the section have a paleotropic distribution and are found throughout Africa. Many of them are regarded as obligate CAM plants, includingE. tirucalli which was used as a comparison in ecophysiological experiments examining the response ofE. aphylla to drought and temperature.     

A Bryophyte Flora of Kent. IV. Addenda and Corrigenda

Abstract

Based on a revision of Andreaea from the Canary Islands, the occurence of two species is confirmed. A key is provided. A. crassifolia Luisier occurs on Gran Canaria, La Palma and Tenerife. A. heinemannii Hampe &; Müll.Hal. occurs on La Palma. Former records of A. heinemannii s.l. for Gran Canaria and Tenerife refer to A. crassifolia.     

Clitopilus canariensis (Basidiomycota, Entolomataceae), a new species in the C. nitellinus-complex (Clitopilus subg. Rhodophana) from the Canary Islands (Spain)

Clitopilus canariensis is described as a new species belonging to Clitopilus subgenus Rhodophana on the basis of a collection from La Palma, Canary Islands. The new species grows on humus of Cistus monspeliensis and is known from a single site. A photograph of fresh basidiomes of the type-collection and line drawings are provided.     

Reconciling gene trees with organism history: the mtDNA phylogeography of three Nesotes species (Coleoptera: Tenebrionidae) on the western Canary Islands

The processes of island colonization and speciation are investigated through mtDNA studies on Canary Island beetles. The genus Nesotes (Coleoptera: Tenebrionidae) is represented by 19 endemic species on the Canary Islands, the majority of which are single island endemics. Nesotes conformis is the most widespread, occurring on Gran Canaria, Tenerife, La Palma and El Hierro. Nesotes conformis forms a paraphyletic assemblage, with a split between Gran Canaria and the other three islands. Nesotes conformis of the western Canary Islands cluster with Nesotes altivagans and Nesotes elliptipennis from Tenerife. Fifty‐two individuals from this western islands species complex have been sequenced for 675 base pairs of the mtDNA cytochrome oxidase II gene, representing Tenerife, La Palma and El Hierro. A neighbour joining analysis of maximum likelihood distances resulted in three distinct mtDNA lineages for N. conformis, two of which also include mitotypes of N. altivagans and N. elliptipennis. Through application of parametric bootstrap tests, we are able to reject hypotheses of monophyly for both N. conformis and N. altivagans. Nesotes altivagans and N. elliptipennis are poorly separated morphologically and mtDNA sequence data adds support to this being one species with a highly variable morphology. We propose that N. altivagans/N. elliptipennis is recently derived from two ancestral mtDNA lineages within N. conformis from the Teno region of Tenerife. We further propose colonization of the younger islands of La Palma and El Hierro by N. conformis from a mitochondrial lineage within the Teno massif (colonization; diversification; mitochondrial DNA; Canary Islands; Coleoptera).     

A review on the impacts of feral cats (Felis silvestris catus) in the Canary Islands: implications for the conservation of its endangered fauna

Feral cats have been directly responsible for the extinction of numerous species on islands worldwide, including endemic species of mammals, birds and reptiles. The diet of feral cats in the main habitats of the Canary Islands, as generally occurred on oceanic islands, is mainly composed of introduced mammals, and native species of birds, reptiles and insects. The impact of feral cat upon the endangered species was assessed by evaluating their relative abundance in the cats’ diet and by considering their current conservation status. A total of 68 different preys were identified at species level in all studies carried out in the Canary Islands (5 mammals, 16 birds, 15 reptiles and 32 invertebrates). From all the species preyed by feral cats in the Canary Islands, only four of them are considered threatened by the IUCN Red List of Threatened Species: one endemic bird Saxicola dacotiae and three endemic giant lizards, Gallotia simonyi, Gallotia intermedia, and Gallotia gomerana. Although some efforts on management control have been carried out, it is necessary to enforce these conservation activities on those areas of Tenerife, La Gomera and El Hierro where giant lizards are still present. Furthermore some local areas where endangered bird species are highly predated should be protected. Nevertheless, it is important to take into account the presence of other introduced species such as rats, mice or rabbits in order to avoid problems derived from the hyperpredation process and mesopredator release effect.     

Genetic bottleneck in invasive species: the potato tuber moth adds to the list

The level of genetic diversity within populations of introduced species has received increasing attention as an important factor influencing their survival and adaptive potential. We examined this issue with the Guatemalan potato tuber moth Tecia solanivora, an agricultural pest which has successfully invaded South America and the Canary Islands within the last 20 years. To analyse changes in T. solanivora genetic diversity, the mitochondrial marker cytochrome b was sequenced from individuals collected across its known distribution area. High haplotypic diversity was observed in Guatemala, whereas only three haplotypes have been found in Venezuela and a single one in the remaining invaded South American countries and the Canary Islands. Invasive haplotypes were not observed in our samples from Guatemala but are closely related to Guatemalan haplotypes. These results are consistent with the hypotheses that (i) either a few individuals were introduced into Venezuela leading to a strong initial genetic bottleneck, or selection pressure may have lead to the disparition of all but a reduced number of introduced haplotypes, (ii) a second bottleneck occured between Venezuela and Colombia, and (iii) the invasion of the Canary Islands originated from South America. We further reviewed the recent literature to compare this change in genetic diversity with those reported for other invasive species. We quantified the changes in genetic diversity between native and introduced ranges for 57 biological invasions. We found that the genetic homogenization in T. solanivora was among the strongest reported and discuss factors that can explain the success of invasive populations with low genetic diversity.     

The Genus Obelus Hartmann, 1842 (Gastropoda, Pulmonata, Helicoidea) and its Phylogenetic Relationships

The genus Obelus, so far known from shells only, is re-described on the basis of the anatomy of its genital system. Its range is here restricted to north-western Africa and the Canary Islands. Four species are traditionally listed for the Canary Islands: Obelus despreauxii, O. moderatus, O. mirandae and O. cyclodon. The presence of the last species on the Canary Islands is doubtful, whereas the fossil/subfossil presence of O. pumilio is documented. The species Helix morata also belongs to the genus, as well as a new species, O. discogranulatus sp. nov. The genital systems of all confirmed extant Canarian species are shown. Obelus has a peculiar vaginal stimulator appendix (“appendicula”) which is homologous to the penial appendix of the Orthurethra and to the stimulatory organ of other Stylommatophora, with the exception that the A₃ portion is missing. The genus is diagnosed by characters of the vaginal stimulator appendix, such as a curved, finger-like A₂ portion of the appendicula ending proximally in a blind, well-developed muscular sac, and by the slender tubular A₄ portion arising laterally from the muscular sac duct. We conclude that Obelus belongs to the Cochlicella group because it shares an appendicula with the other genera of the group. However, it differs in anatomical details of this structure. The Cochlicella group should be recognized as a separate family Cochlicellidae Schileyko, 1972, with close relationships to the Helicellidae and the Hygromiidae. A new diagnosis for Cochlicellidae is proposed and its phylogenetic relationships are discussed.This is: Notes on the Malacofauna of the Canary Islands, No. 46.     

Octopods of the Canary Islands. New records and biogeographic relationships

Two octopod species are reported from the Canary Islands (eastern Atlantic Ocean) for the first time: the deep sea four-horn octopus, Pteroctopus tetracirrhus (Delle Chiaje, 1830) and the gelatinous giant octopus, Haliphron atlanticus Steenstrup, 1861. Both female specimens were caught in Tenerife. Haliphron atlanticus is described from fresh remains found floating close to the southwest coast and the second species, P. tetracirrhus, is described from a specimen captured in a shrimp trap at 200 m depth on the southeastern coast of Tenerife. With these two additions the revised and updated list of octopod species of the Canary Islands now comprises eight families and 18 species, all of them incirrate octopods. The zoogeographic relationships of octopod species from other Atlantic regions, including the Mediterranean Sea, were studied. The likely directions of faunal flows were inferred based on affinity indices, showing that Mauritania could be the most probable source of the octopod species of the Canary Islands and the rest of the Macaronesian archipelagos.     

Radiation of Atlantic goldcrests Regulus regulus spp.: evidence of a new taxon from the Canary Islands

Phylogenetic relationships between goldcrest populations from the Atlantic Islands (Azores and Canary Islands) were investigated by two molecular markers (mitochondrial control region and cytochrome b sequences), and partly by morphology and territorial song. The Azorean goldcrest populations are closely related to European nominate R. r. regulus. Most probably, the Azores were colonized by goldcrests in a single late‐pleistocene invasion, while colonization of the Canary Islands presumably occurred in two steps: An early invasion to Tenerife and La Gomera 1.9–2.3 million years (my) ago and a more recent one to El Hierro and La Palma 1.3–1.8 my ago. Distribution of haplotypes on the Azores suggests a division of R. r. azoricus on São Miguel into an eastern population with close affinities to R. r. sanctaemariae and a western population belonging to the lineage of R. r. inermis on the central and western island group. The Canarian populations are genetically substructured into a northeastern group embracing Tenerife and La Gomera and a second, southwestern group including El Hierro and La Palma. Genetic distances between members of the two Canarian clades range at 3.1–3.4% (TrN distance, control region and cytochrome b). Differentiation between the two groups is also supported by morphology and by territorial song. Substitution rate estimates for the both genes range at approximately the same values of 0.0031 and 0.0044 substitutions per site and lineage per my which roughly corresponds 0.61–0.83% divergence between Regulus lineages per my. Highest local rates occur in island clades of the Azorean and the Canarian population and in R. r. japonensis from the Russian Far East and Japan. However, a general acceleration of a molecular clock in island populations is not evident from the Regulus data set due to extremely low local rate estimates in the Canarian clade of Tenerife and La Gomera. As a taxonomic consequence of the marked differentiation of the two Canarian goldcrest clades the populations from El Hierro and La Palma are described as a taxon new to science and are named Regulus regulus ellenthalerae n. ssp.     

Delimiting species boundaries for endangered Canary Island grasshoppers based on DNA sequence data

Mitochondrial DNA cytochrome oxidase subunit I and nuclear ITS2 sequences were surveyed from Canary Islands threatened species of the genera Purpuraria and Acrostira (Orthoptera: Pamphagidae). Phylogenetic and population analyses show that the two previously recognized Purpuraria erna subspecies are not valid as conservation units, and that there is a new unrecognized species of Purpuraria, coincident with recently discovered morphological variation within the genus. In addition, mitochondrial introgression seems to occur between the two Purpuraria species in southwest Lanzarote. Species-delimitation based on the morphological taxonomy of Acrostira, which recognizes four single-island endemics, is only partially supported by the genetic data. It shows that currently admitted species from the central and western islands of Tenerife, La Gomera and La Palma are closely related, with evidence of recent gene flow between the Tenerife and La Gomera populations. MtDNA variation also showed that A. euphorbiae, currently considered as the most critically endangered grasshopper species in the Canaries, has lower population diversity than its close relatives.     

Complex population genetic structure in the endemic Canary Island pine revealed using chloroplast microsatellite markers

The Canary archipelago, located on the northwestern Atlantic coast of Africa, is comprised of seven islands aligned from east to west, plus seven minor islets. All the islands were formed by volcanic eruptions and their geological history is well documented providing a historical framework to study colonization events. The Canary Island pine (Pinus canariensis C. Sm.), nowadays restricted to the westernmost Canary Islands (Gran Canaria, Tenerife, La Gomera, La Palma and El Hierro), is considered an old (Lower Cretaceous) relic from an ancient Mediterranean evolutionary centre. Twenty seven chloroplast haplotypes were found in Canary Island pine but only one of them was common to all populations. The distribution of haplotypic variation in P. canariensis suggested the colonization of western Canary Islands from a single continental source located close to the Mediterranean Basin. Present-day populations of Canary Island pine retain levels of genetic diversity equivalent to those found in Mediterranean continental pine species, Pinus pinaster and Pinus halepensis. A hierarchical analysis of variance (AMOVA) showed high differentiation among populations within islands (approximately 19%) but no differentiation among islands. Simple differentiation models such as isolation by distance or stepping-stone colonization from older to younger islands were rejected based on product-moment correlations between pairwise genetic distances and both geographic distances and population-age divergences. However, the distribution of cpSSR diversity within the islands of Tenerife and Gran Canaria pointed towards the importance of the role played by regional Pliocene and Quaternary volcanic activity and long-distance gene flow in shaping the population genetic structure of the Canary Island pine. Therefore, conservation strategies at the population level are strongly recommended for this species.Communicated by D.B. NealeA. Gómez and S.C. González-Martínez as joint authors     

Evolution of an invasive rodent on an archipelago as revealed by molar shape analysis: the house mouse in the Canary Islands

Aim The aim of this paper is to identify the patterns in the morphological differentiation in Canary Island mice, based on fossil and modern samples. In order to achieve this, the mouse species present on the archipelago were first compared with a set of continental mice. The differences between the continental and Canary Island samples, and among the Canary Island samples, provide insights into the processes of colonization and the subsequent insular evolution. Location Canary archipelago. Methods An outline analysis based on Fourier transformation was used to quantify shape differences between lower molars. Together with the fossil and modern Canary Island samples, a reference set of genotyped continental populations of the commensal Mus musculus and the wild Mus spretus was used for comparison. Results The morphometric analysis showed that all the mouse specimens from the Canary Islands and Cape Verde belonged to Mus musculus domesticus. Lower molars of extant mice from La Gomera, El Hierro, Gran Canaria, Tenerife, and to a lesser degree from Lanzarote, were similar to those of genotyped M. m. domesticus from the continent, while teeth of extant mice from Fuerteventura were more divergent. Fossil mice from Fuerteventura were very similar to the extant representatives on this island, and similar to the fossil mice on the nearby islands of Lobos and La Graciosa. Main conclusions The mouse present on the Canary archipelago has been identified as the house mouse M. m. domesticus. Based on the shape of the lower molar, the Canary Island mice are divergent from the continental ones, but the degree of divergence varies with the geography of the archipelago. Overall, populations from eastern islands are more divergent from the continental mice than populations from western ones. Fossil populations indicate that this situation was established several centuries ago. Two main factors may have contributed to this pattern: the appearance of different types of environment on the islands since the successful settlement of the mouse, and/or the number of subsequent introductions of continental individuals via shipping.     

Chemotaxonomy of Gonospermum and related genera

Aerial parts of Gonospermum fruticosum collected at several locations in the Canary Islands afforded, in addition to known compounds, four sesquiterpene alcohols related to costol and a sesquiterpene lactone, whose structures were established on the basis of their spectroscopic data and chemical transformations. Except for Gonospermum species collected on the island of Tenerife, those collected on the island of El Hierro and, in a previous study those from La Gomera, contain sesquiterpene lactones that can be used as chemotaxonomic markers confirming the inclusion of Gonospermum, Lugoa, and species of Tanacetum endemic to the Canary Islands in a genus that does not support the monophyly of Gonosperminae.     

A genetic contribution to the taxonomy ofOenothera sect.Oenothera (including subsectionsEuoenothera,Emersonia, Raimannia andMunzia)

Based on an analysis of results from experimental hybridization, the plants assigned byMunz toOenothera subg.Oenothera and subg.Raimannia, now divided into approximately 76 species, are referred to a single section,Oenothera. This section is in turn divided into five subsections:Euoenothera, Munzia, Raimannia, Emersonia, and an undescribed group of three species related toOenothera pubescens. Euoenothera is maintained in the traditional sense, and includes about 14 species of North America, widely naturalized elsewhere.Munzia consists of 45 species, comprising three series, and native to South America.Raimannia is restricted to a group of approximately 11 North American species.Emersonia comprises four rather heterogenous species of northern Mexico and southern New Mexico, of whichOenothera macrosceles, O. maysillesii, andO. organensis have been described. Within these four subsections, interspecific hybrids can be made in general, although plastid differentiation often leads to incompatibilities. With varying degrees of difficulty, hybrids were produced in all intersectional combinations involvingEuoenothera, Emersonia, Munzia, andRaimannia, the most difficult being those betweenEmersonia andRaimannia. Based on their habit and distribution,Emersonia species, and especiallyOenothera maysillesii, appear to resemble most closely the common ancestor of the section,Euoenothera andMunzia to have been derived from it or its common ancestor, andRaimannia perhaps to be more closely related to the phylogenetic branch that leads toEuoenothera.