Aim To understand why and when areas of endemism (provinces) of the tropical Atlantic Ocean were formed, how they relate to each other, and what processes have contributed to faunal enrichment.Location Atlantic Ocean.Methods The distributions of 2605 species of reef fishes were compiled for 25 areas of the Atlantic and southern Africa. Maximum-parsimony and distance analyses were employed to investigate biogeographical relationships among those areas. A collection of 26 phylogenies of various Atlantic reef fish taxa was used to assess patterns of origin and diversification relative to evolutionary scenarios based on spatio-temporal sequences of species splitting produced by geological and palaeoceanographic events. We present data on faunal (species and genera) richness, endemism patterns, diversity buildup (i.e. speciation processes), and evaluate the operation of the main biogeographical barriers and/or filters.Results Phylogenetic (proportion of sister species) and distributional (number of shared species) patterns are generally concordant with recognized biogeographical provinces in the Atlantic. The highly uneven distribution of species in certain genera appears to be related to their origin, with highest species richness in areas with the greatest phylogenetic depth. Diversity buildup in Atlantic reef fishes involved (1) diversification within each province, (2) isolation as a result of biogeographical barriers, and (3) stochastic accretion by means of dispersal between provinces. The timing of divergence events is not concordant among taxonomic groups. The three soft (non-terrestrial) inter-regional barriers (mid-Atlantic, Amazon, and Benguela) clearly act as 'filters' by restricting dispersal but at the same time allowing occasional crossings that apparently lead to the establishment of new populations and species. Fluctuations in the effectiveness of the filters, combined with ecological differences among provinces, apparently provide a mechanism for much of the recent diversification of reef fishes in the Atlantic.Main conclusions Our data set indicates that both historical events (e.g. Tethys closure) and relatively recent dispersal (with or without further speciation) have had a strong influence on Atlantic tropical marine biodiversity and have contributed to the biogeographical patterns we observe today; however, examples of the latter process outnumber those of the former.

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How do biogeographically different provinces arise in response to oceanic barriers to dispersal? Here, we analyse how traits related to the pelagic dispersal and adult biology of 985 tropical reef fish species correlate with their establishing populations on both sides of two Atlantic marine barriers: the Mid-Atlantic Barrier (MAB) and the Amazon -Orinoco Plume (AOP). Generalized linear mixed-effects models indicate that predictors for successful barrier crossing are the ability to raft with flotsam for the deep-water MAB, non-reef habitat usage for the freshwater and sediment-rich AOP, and large adult-size and large latitudinal-range for both barriers. Variation in larval-development mode, often thought to be broadly related to larval-dispersal potential, is not a significant predictor in either case. Many more species of greater taxonomic diversity cross the AOP than the MAB. Rafters readily cross both barriers but represent a much smaller proportion of AOP crossers than MAB crossers. Successful establishment after crossing both barriers may be facilitated by broad environmental tolerance associated with large body size and wide latitudinal-range. These results highlight the need to look beyond larval-dispersal potential and assess adult-biology traits when assessing determinants of successful movements across marine barriers.

Many tropical reef fishes are divided into Atlantic and East Pacific taxa, placing similar species in two very different biogeographic regimes. The tropical Atlantic is a closed ocean basin with relatively stable currents, whereas the East Pacific is an open basin with unstable oceanic circulation. To assess how evolutionary processes are influenced by these differences in oceanography and geography, we analyze a 630-bp region of mitochondrial cyto-chrome b from 171 individuals in the blenniid genus Ophioblennius. Our results demonstrate deep genetic structuring in the Atlantic species, O. atlanticus, corresponding to recognized biogeographic provinces, with divergences of d 5.2-12.7% among the Caribbean, Brazilian, St. Helena/Ascension Island, Gulf of Guinea, and Azores/Cape Verde regions. The Atlantic phylogeny is consistent with Pliocene dispersal from the western to eastern Atlantic, and the depth of these separations (along with prior morphological comparisons) may indicate previously unrecognized species. The eastern Pacific species, O. steindachneri, is characterized by markedly less structure than O. atlanticus, with shallow mitochondrial DNA lineages (d max 2.7%) and haplotype frequency shifts between locations in the Sea of Cortez, Pacific Panama, Clipperton Island, and the Galapagos Islands. No concordance between genetic structure and biogeographic provinces was found for O. steindachneri. We attribute the phylogeographic pattern in O. atlanticus to dispersal during the reorganization of Atlantic circulation patterns that accompanied the shoaling of the Isthmus of Panama. The low degree of structure in the eastern Pacific is probably due to unstable circulation and linkage to the larger Pacific Ocean basin. The contrast in genetic signatures between Atlantic and eastern Pacific blennies demonstrates how differences in geology and oceanography have influenced evolutionary radiations within each region.

The temperate, gonochoristic wrasse Symphodus ocellatus was studied in the field (Corsica). The largest males defend an area within which an average of 3-5 successive nests are built from algae. These brightly coloured, paternal, territorial males (T-males) spend between one and two thirds of their time during the 10-day nest cycle building the nest and fanning. They eat very little at this time, although they consume eggs and invertebrates in the nest, including egg predators. T-males occasionally take over neighbouring nests. Nest acquisition has two functions: nourishment (2/3 of all take-overs) and reproduction (1/3). T-males practising the latter save over 1/3 of the time of a complete nest cycle. Most take-over males that acquire nests solely for nourishment fan it, as do their reproducing counterparts. Small males with inconspicuous female colouration roam about and try to fertilize eggs parasitically when females spawn in T-males' nests. There are usually several of these "sneakers" around successful nests. Medium sized males (smaller than T-males and differently coloured) also cuckold T-males, but often display submissively to them. They participate in nest defence against conspecifics and in interactions with females, with an average effort that even exceeds that of the nest owners. Males displaying this "satellite behaviour" feed much less than sneakers and remain at one nest during most of its spawning phase. They are more tolerated by T-males than are sneakers, although they are on average only half as far away from the nest and thus much more frequently encountered by the T-male. The proportion of time a male spends as a satellite depends on its size. Usually only the largest accessory male at a nest behaves in this manner, though smaller males occasionally perform elements of satellite behaviour. Satellites never participate in nest building, courtship, direct broodcare or interspecific defence, nor do they take over abandoned nests. A fourth type of male, similar in size and appearance to sneakers and satellites, refrains from reproduction in a specific year. These males are perhaps future T-males. All females seem to participate in reproduction every year. They spawn repeatedly in the same nest over one day, but often change nests and T-males on successive days. Male tactics are roughly determined by size, but there are still choices to be made, such as when to give up a nest which has little spawning success, whether to build a nest or to attempt a take-over, or when to reproduce and whether to adopt the sneaker or satellite roles. The simultaneous occurrence of T-males, satellites and sneakers within a species is compared to a few other examples of diverse taxa.

The Azores, Madeira, Selvagens, Canary Islands and Cabo Verde are commonly united under the term “Macaronesia”. This study investigates the coherency and validity of Macaronesia as a biogeographic unit using six marine groups with very different dispersal abilities: coastal fishes, echinoderms, gastropod molluscs, brachyuran decapod crustaceans, polychaete annelids, and macroalgae. We found no support for the current concept of Macaronesia as a coherent marine biogeographic unit. All marine groups studied suggest the exclusion of Cabo Verde from the remaining Macaronesian archipelagos and thus, Cabo Verde should be given the status of a biogeographic subprovince within the West African Transition province. We propose to redefine the Lusitanian biogeographical province, in which we include four ecoregions: the South European Atlantic Shelf, the Saharan Upwelling, the Azores, and a new ecoregion herein named Webbnesia, which comprises the archipelagos of Madeira, Selvagens and the Canary Islands.

A check-list of the coastal fishes of Madeira Island is presented. The species Rhincodon typus, Megalops atlanticus, Apterichtus caecus, Apterichtus sp., Chelidonichthys lucernus, Caranx crysos, Lutjanus goreensis, Crystallogobius linearis, and Canthidermis sufflamen are recorded for the first time from Madeira waters. We have recognized 13 previous records as identification errors or registration errors and indicate 14 other records as doubtful. Including the nine new records, we list 226 species from the coastal waters of Madeira Island.

This paper presents an analysis of the distributional patterns of blenniids (Pisces: Blenniidae) in the north-eastern Atlantic. Two peaks of species diversity were found, both in terms of number of species and number of endemics: one in the tropical African coast and another in the Mediterranean Sea. A cluster analysis of similarity values (Jaccard coefficient) among the eastern Atlantic zoogeographical areas, revealed the following groups: a north temperate group, a tropical group formed by the tropical African coast and Mauritania, another group formed by the islands of Cape Verde, a south temperate group (South Africa), and a southern Atlantic group formed by the islands of Ascension and St Helena. Within the north temperate group, the subgroups with higher similarities were: Azores and Madeira, Canary Islands and Morocco, and the Mediterranean and the Atlantic coast of the Iberian Peninsula. Based on affinity indices, the probable directions of faunal flows were inferred. The tropical coast of Africa and the Mediterranean emerged from this analysis as probable speciation centres of the north-eastern Atlantic blenniid fauna. The Mediterranean may have also acted as a refuge during glacial periods.