Phylogeography of the mottled spinefoot Siganus fuscescens: Pleistocene divergence and limited genetic connectivity across the Philippine archipelago

Historical isolation during Pleistocene low sea level periods is thought to have contributed to divergence among marine basin populations across the Coral Triangle. In the Philippine archipelago, populations in the South China Sea, Sulu Sea–inland seas, and Philippine Sea‐Celebes Sea basins might have been partially isolated. Meanwhile, present‐day broadscale oceanographic circulation patterns suggest connectivity between these basins. To evaluate hypotheses regarding the influence of historical and contemporary factors on genetic structure, phylogeographic patterns based on mitochondrial control region sequences for a reef‐associated fish, Siganus fuscescens, were analysed. Three distinct lineages were recovered. One lineage was identified as the morphologically similar species Siganus canaliculatus, while two lineages are monophyletic with S. fuscescens. Clade divergence and demographic expansion in S. fuscescens occurred during the Pleistocene. A strong signal of latitudinal structure was detected (Φ_CT = 0.188), driven by marked differences in clade distribution: one clade is widely distributed (clade A), while a second clade (clade B) has a restricted northern distribution. Regional structure of clade A is consistent with the basin isolation hypothesis (Φ_CT = 0.040) and suggests isolation of the South China Sea (Φ_CT = 0.091). Fine‐scale structure was observed in the South China Sea and south Philippine Sea, while Sulu Sea and inland seas were unstructured. Genetic structure across multiple spatial scales (archipelagic, regional, and fine‐scale within basins) suggests the influence of vicariant barriers and contemporary limits to gene flow in S. fuscescens that may be influenced by oceanographic circulation, geographical distance between available habitats, and latitudinal temperature differences.     

Serum Malondialdehyde Correlates with Therapeutic Efficiency of High Activity Antiretroviral Therapies (HAART) in HIV-1 Infected Children

Serum malondialdehyde (MDA) levels are increased in human immunodeficiency virus (HIV)-infected children, as it happens also in infected adult individuals. Introduction of high activity antiretroviral therapy (HAART) has promoted an intense decline in morbidity and mortality of these patients. Here we present data on the effect of HAART on serum MDA of HIV+ children and compare them with levels prior to HAART. MDA levels reflect, as other markers do, the HAART-induced clinical improvement and probably also the pro-oxidant/antioxidant side effects of the different drugs used. The results herein allow the proposal of including serum MDA levels as an additional parameter for the clinical management of HIV+ children.     

Plasticity and limitations of extended egg retention in oviparous Zootoca vivipara (Reptilia: Lacertidae)

The transition between oviparity and viviparity in reptiles is generally accepted to be a gradual process, the result of selection for increasingly prolonged egg retention within the oviduct. We examined egg retention plasticity in an oviparous strain of the lacertid lizard Zootoca vivipara, a species having both oviparous and viviparous populations. We forced a group of female Z. vivipara to retain their clutch in utero by keeping them in dry substrata, and assessed the effect on embryonic development and hatching success, along with offspring phenotype and locomotor performance. Forced egg retention for one additional week affected the developmental stage of embryos at oviposition, as well as hatchling robustness and locomotor performance. However, embryos from forced clutch retention treatment reached one stage unit more than control embryos at oviposition time. Embryos from control eggs were more developed than embryos from experimental eggs after approximately the same period of external incubation, showing that embryonic development is retarded during the period of extended egg retention, despite the high temperature inside the mother's body. Significant differences in external incubation time were only found in one of the two years of study. Hatching success was much lower in the experimental group with forced egg retention (21.1%) than in the control group (95.4%). Therefore, we conclude that there are limitations that hinder the advance of intrauterine embryonic development beyond the normal time of oviposition, and that extended egg retention does not represent clear advantages in this population of Z. vivipara. Nevertheless, the fact that some eggs are successful after forced egg retention could be advantageous for the females that are able to retain their clutch under unfavourable climatic conditions. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102 , 75–82.     

Identifying biases at different spatial and temporal scales of diversification: a case study in the Neotropical parrotlet genus Forpus

The temporal origins of the extraordinary biodiversity of the Neotropical region are highly debated. Recent empirical work has found support for alternative models on the tempo of speciation in Neotropical species further fuelling the debate. However, relationships within many Neotropical lineages are poorly understood, and it is unclear how this uncertainty impacts inferences on the evolution of taxa in the region. We examined the robustness of diversification patterns in the avian genus Forpus by testing whether the use of different units of biodiversity (i.e. biological species and statistically inferred species) impacted diversification rates and inferences regarding important biogeographic breaks in the genus. We found that the best‐fit model of diversification for the biological species data set was a declining rate of diversification; whereas a model of constant diversification was the best‐fit model for statistically inferred species or subspecies. Moreover, the relative importance of different landscape features in delimiting genetic structure across the landscape varied across data sets with differing units of biodiversity. Patterns based on divergence times among biological species indicated old speciation events across major geographic and river barriers. In contrast, data sets more inclusive of the diversity in Forpus illustrate the role of both old divergence across major landscape features and more recent divergences that are possibly attributed to Pleistocene climatic changes. Overall, these results indicate that conflicting models on the temporal origins of Neotropical birds may be attributable to sampling biases.     

Does allometry of a sexually selected ornamental trait vary with sexual selection intensity? A multi‐species test in damselflies

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The Straits of Gibraltar: barrier or bridge to Ibero‐Moroccan bat diversity?

Genetic divergence in bat communities was assessed on both sides of the Straits of Gibraltar and cryptic diversity was examined. Screening was carried out using partial sequences of the mitochondrial (mt)DNA cytochrome b gene on 399 individual bats belonging to the 18 species found on both sides of the Straits of Gibraltar. For those bats that showed important genetic discontinuities, molecular markers (ND1 and nuclear RAG2 genes) were added to expand the sampling process. Phylogenetic reconstructions were obtained using maximum parsinomy, genetic distances, maximum likelihood, and Bayesian criteria. As an estimate of bats' flight performance, we measured for each species the wing aspect ratio and wing loading indexes, and correlated them with the maximum pairwise genetic distances obtained between southern Iberian and northern Moroccan populations. Genetic mtDNA distances between populations on both continents exceed 5% in seven out of 18 bat species analysed and unknown lineages were uncovered within the species complexes Myotis nattereri and Myotis mystacinus . We did not find a general pattern in the degree of permeability of the Straits of Gibraltar for bats. Genetic distances were not correlated with the ability to cross the Straits. Our study shows that the cryptic diversity uncovered among bats continues to increase as more regions are studied.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 96 , 434–450.     

The genetic basis of early‐life morphological traits and their relation to alternative male reproductive tactics in Atlantic salmon

Although heritability estimates for traits potentially under natural selection are increasingly being reported, their estimation remains a challenge if we are to understand the patterns of adaptive phenotypic change in nature. Given the potentially important role of selection on the early life phenotype, and thereby on future life history events in many fish species, we conducted a common garden experiment, using the Atlantic salmon (Salmo salar L.), with two major aims. The first objective is to determine how the site of origin, the paternal sexual tactic and additive genetic effects influence phenotypic variation of several morphological traits at hatching and emergence. The second aim is to test whether a link exists between phenotypic characteristics early in life and the incidence of male alternative tactics later in life. We found no evidence of a site or paternal effect on any morphological trait at hatching or emergence, suggesting that the spatial phenotypic differences observed in the natural river system from which these fish originated are mainly environmentally driven. However, we do find significant heritabilities and maternal effects for several traits, including body size. No direct evidence was found correlating the incidence of precocious maturation with early life characteristics. We suggest that under good growing conditions, body size and other traits at early developmental stages are not reliable cues for the surpassing of the threshold values associated with male sexual development.     

Morphology and DNA barcoding reveal three species in one: description of Culicoides cryptipulicaris sp. nov. and Culicoides quasipulicaris sp. nov. in the subgenus Culicoides

Species of the genus Culicoides (Diptera: Ceratopogonidae) are well known for their importance in the field of medical and veterinary entomology. Culicoides spp. transmit a wide variety of pathogens, primarily viruses that affect animals and humans. In Europe, the most economically important disease transmitted by Culicoides is bluetongue (BT). Culicoides spp. have been recently involved as primary vectors for Schmallenberg disease. The taxonomy within the subgenus Culicoides has been historically difficult and reorganizations have been proposed regularly. The subgenus Culicoides includes species that are considered to be potential vectors for BT. High morphological intraspecific variability has been attributed to these species. This highlights the apparent presence of previously undetected cryptic species diversity in the subgenus. In the present study, a detailed morphological and molecular study of specimens belonging to Culicoides pulicaris s.l. and specimens resembling a cross between C. pulicaris and Culicoides punctatus revealed the presence of two new species: Culicoides cryptipulicaris and Culicoides quasipulicaris. Females of C. quasipulicaris and males of both species were morphologically distinguished from C. pulicaris (Linnaeus, 1758), whereas females of C. cryptipulicaris were identified using molecular techniques exclusively.