The presence of lateral photophores correlates with increased speciation in deep-sea bioluminescent sharks

The vast majority of species within the lanternshark genus Etmopterus harbour complex luminescent markings on their flanks, whose functional significance has long remained obscure. Recent studies, however, suggest these enigmatic photophore aggregations to play a role in intraspecific communication. Using visual modelling based on in vivo luminescence measurements from a common lanternshark species, we show that etmopterid flank markings can potentially work as a medium range signal for intraspecific detection/recognition. In addition, using molecular phylogenetic analyses, we demonstrate that the Etmopterus clade exhibits a greater than expected species richness given its age. This is not the case for other bioluminescent shark clades with no (or only few) species with flank markings. Our results therefore suggest that etmopterid flank markings may provide a way for reproductive isolation and hence may have facilitated speciation in the deep-sea.

Lizards from central Jatapú River, Amazonas, Brazil

The present study reports an inventory of lizard species from a region at the central Jatapú River located in the state of Amazonas, Brazil. The lizard fauna was surveyed using three sampling methods: diurnal and nocturnal visual search, pitfall traps with drift fences, and incidental collections. We recorded 24 lizard species belonging to 18 genera and eight families. Non-parametric estimators of richness (Bootstrap, Chao 2, Jackknife 1, Ace) were used to estimate the percentage of total richness sampled. Expected species richness varied from 27 species estimated via Bootstrap to 30 species with Jackknife 1. The composition of the lizard fauna encountered in the rio Jatapú plot was compared with seven other published surveys carried out in the region of the Brazilian Guiana Shield. The composition of the Jatapú lizard fauna was most similar to FLOTA Faro (84%) and least similar to ESEC Grão-Pará Center (66%). There was no association between faunal similarity and geographic distance. The present species list contributes to our knowledge of lizards of the southern portion of the Guiana Shield in Brazil.

Faunistic analysis of the species of Anastrepha Schiner (Diptera: Tephritidae) in three municipalities of the state of Roraima, Brazil

The purpose of this work was to describe the population patterns of Anastrepha in three municipalities of the state of Roraima, Brazil, via faunistic analysis. Weekly collections were performed from January through December 2008, using McPhail traps containing 5% hydrolysed protein, in domestic orchards in the municipalities of Boa Vista, Bonfim and Pacaraima. We captured 301 females of Anastrepha in Boa Vista, 212 in Bonfim, and 167 in Pacaraima. Boa Vista presented the highest species richness (S = 10) and Pacaraima the lowest (S = 4). Anastrepha striata was the predominant species in Boa Vista (47.18%) and Pacaraima (65.87%), whereas A. obliqua predominated in Bonfim (46.23%). Boa Vista presented the highest Shannon-Wiener diversity index (H' = 1.19) and Margalef index (α = 1.58), and Bonfim presented the highest Pielou's evenness index (J' = 0.69). In Pacaraima the cumulative curves reached stability, confirming that the observed and expected species richness were the same. In the other two municipalities, the curves showed a moderate growth, suggesting that the sampling effort was not sufficient to produce an accurate depiction of species richness. In this study, Anastrepha zernyi is reported for the first time in Roraima.

Distribution of moss-inhabiting diatoms along an altitudinal gradient at sub-Antarctic Îles Kerguelen

Altitudinal gradients provide excellent opportunities to study relationships between species distribution and climatic variables. We studied the species composition of 39 samples of moss-inhabiting diatoms, collected at 50 m intervals from 100–650 m above sea level. The samples contained a total of 130 diatom species, of which 51 occurred in 10 or more samples. Altitude appeared to be the most important variable explaining variation in species composition. Of the 51 common species, 33 showed a significant relationship with altitude. Although the majority of the latter declined with increasing altitude, for nine species the probability of occurrence first increased with increasing elevation, but decreased again at higher altitudes, and four species increased systematically with elevation. As a result, expected species richness per sample decreased from an estimated 43 at 100 m to 25 species per sample at 650 m. Diatom distribution patterns proved to be suitable predictors of the altitudinal position of sample sites. Cross-validation yielded a strong relationship between predicted and observed altitudes.