Intraspecific Abundance–Occupancy–Patchiness Relations in the Intertidal Benthic Macrofauna of a Cool-Temperate North Sea Mudflat

The macroecological variable of patchiness (Lloyd’s Ip index of patchiness, P) has recently been shown to be related inter- and intraspecifically to those of abundance (numbers m−2, A), and occupancy (% occurrence in samples, O) in lower latitude seagrass macrofaunas. For the first time in higher latitudes, intraspecific relationships between three spatial variables were investigated in the intertidal mudflat macrobenthos of the Scolt Head barrier island, southern North Sea (53° N, 01° E). Sampling was conducted between early July and late September 2009–2013 using 710-µm mesh for sample processing. Strong positive interspecific A-O and negative interspecific P-O and P-A relationships were present. Two of the most numerous and widespread assemblage components, however, occurred with effectively constant occupancy (Peringia ulvae, 100%, and Tubificoides benedii, 93%) across the whole 20-ha locality and therefore could not show intraspecific relationships of occupancy with other macroecological metrics. These two apart, only one other dominant species failed to show a significant positive intraspecific A-O relationship; no species showed significant P-A relations of any form; and only two showed the negative P-O ones that have been described elsewhere. The intraspecific A-O patterns appear to contrast with those of an earlier study at another North Sea locality (the Dutch Wadden Sea), although differences are more apparent than real, but the Scolt Head fauna showed fewer intraspecific P-O and P-A relations than those characterising similar circumstances in the two lower-latitude localities previously investigated. Neither developmental mode nor variation in local abundance appears to influence these patterns. A-O-P relations therefore seem widespread but may be subject to latitudinal modification.

Within-species relationship of patchiness to both abundance and occupancy, as exemplified by seagrass macrobenthos

For the first time, intraspecific relationships between the macroecological metrics patchiness (P) and both abundance (A) and occupancy (O) were investigated in a faunal assemblage. As a companion study to recent work on interspecific P, A and O patterns at the same localities, intraspecific patterns were documented within each of the more dominant invertebrates forming the seagrass macrobenthos of warm–temperate Knysna estuarine bay (South Africa) and of sub-tropical Moreton Bay (Australia). As displayed interspecifically, individual species showed strong A–O patterns (mean scaling coefficient − 0.76 and mean R2 > 0.8). All P–O relations were negative and most (67%) were statistically significant, although weaker (mean R2 0.5) than A–O ones; most P–A ones were also negative but fewer (43%) achieved significance, and were even weaker (mean R2 0.4); 33% of species showed no significant interrelations of either O or A with P. No species showed only a significant P–A relationship. Compared with interspecific P–A–O data from the same assemblages, power–law scaling exponents were equivalent, but R2 values were larger. Larviparous species comprised 70% of the total studied, but 94% of those displaying significant patchiness interrelationships; 5 of the 9 showing no P–A or P–O relationships, however, were also larviparous. At Knysna, though not in Moreton Bay, larviparous species also showed higher levels of occupancy than non-larviparous ones, whilst non-larviparous species showed higher levels of patchiness. Dominant Moreton Bay species, but not those at Knysna, exhibited homogeneously sloped P–O relationships.

Origins and chromosome differentiation of Thinopyrum elongatum revealed by PepC, Pgk1 genes and ND-FISH

<i>Thinopyrum elongatum</i> is an important gene pool for wheat genetic improvement. However, the origins of the <i>Thinopyrum</i> genomes and the nature of the genus’ intraspecific relationships are still controversial. In this study, we used single-copy nuclear genes and non-denaturing fluorescence <i>in situ</i> hybridization (ND-FISH) to characterize genome constitution and chromosome differentiation in <i>Th. elongatum</i>. According to phylogenetic analyses based on <i>PepC</i> and <i>Pgk1</i> genes, there was an E genome with three versions (E^e, E^b, E^x) and St genomes in the polyploid <i>Th. elongatum</i>. The ND-FISH results of pSc119.2 and pAs1 revealed that the karyotypes of diploid <i>Th. elongatum</i> and <i>Th. bessarabicum</i> were different and the chromosome differentiation occurred among accessions of the diploid <i>Th. elongatum</i>. In addition, the tetraploid <i>Th. elongatum</i> has two groups of ND-FISH karyotype, indicating that the tetraploid <i>Th. elongatum</i> might be a segmental allotetraploid. In summary, our results suggested that the diploid <i>Th. elongatum</i>, <i>Th. bessarabicum</i> and <i>Pseudoroegneria</i> were the donors of the E^e, E^b and St genome to polyploid <i>Th. elongatum</i> species, respectively.

Evaluation of Genetic Diversity of Seven Species of Solanum in Nigeria Using SDS-PAGE

Seed protein profile of 12 accessions belonging to 7 species of the genus Solanum of the family solanaceae were investigated through poly acrylamide gel electrophoresis. The accessions were selected based on their overlapping morphological associations observed on the field. Occurrence of two protein bands of molecular weights 100 kda and 20 kda in all accession showed interspecific relationships and could be used as generic bands among the genus Solanum. All morphologically similar accessions manifested similarities in their protein bands except S. melongena. Dendrogram based on upgma also revealed the generic status and intraspecific relationships of the accession of S. aethiopicum and S. macrocarpon.

Intraspecific Energetic Trade-Offs and Costs of Encephalization Vary from Interspecific Relationships in Three Species of Mormyrid Electric Fishes

The evolution of increased encephalization comes with an energetic cost. Across species, this cost may be paid for by an increase in metabolic rate or by energetic trade-offs between the brain and other energy-expensive tissues. However, it remains unclear whether these solutions to deal with the energetic requirements of an enlarged brain are related to direct physiological constraints or other evolved co-adaptations. We studied the highly encephalized mormyrid fishes, which have extensive species diversity in relative brain size. We previously found a correlation between resting metabolic rate and relative brain size across species; however, it is unknown how this interspecific relationship evolved. To address this issue, we measured intraspecific variation in relative brain size, the sizes of other organs, metabolic rate, and hypoxia tolerance to determine if intraspecific relationships between brain size and organismal energetics are similar to interspecific relationships. We found that 3 species of mormyrids with varying degrees of encephalization had no intraspecific relationships between relative brain size and relative metabolic rate or relative sizes of other organs, and only 1 species had a relationship between relative brain size and hypoxia tolerance. These species-specific differences suggest that the interspecific relationship between metabolic rate and relative brain size is not the result of direct physiological constraints or strong stabilizing selection, but is instead due to other species level co-adaptations. We conclude that variation within species must be considered when determining the energetic costs and trade-offs underlying the evolution of extreme encephalization.

Linear alkanes as a tool to evaluate intraspecific differences in social wasps

Cuticular hydrocarbons are found in the epicuticle of insects and act during interactions between nestmates in social insects. Among the classes of these compounds, branched alkanes stand out acting as flags during intracolonial interactions, therefore, varying significantly intraspecificaly. However, there is evidence that linear alkanes can also act as signals in these interactions and therefore would also be important to assess intraspecific differences in colonies of social insects. Thus, the hypothesis of this study is that linear alkanes can be used as a tool to establish intraspecific relationships in a species of social wasp. Linear alkanes of all developmental stages were evaluated from colonies of the species Mischocyttarus consimilis Zikán (Hymenoptera, Vespidae). 21 linear alkanes were detected, with the majority ranging from n-C26 to n-C33. There is significant variation between the compounds of all developmental stages, both from samples of different colonies and populations. Therefore, the results validate the hypothesis that variation in composition of linear alkanes can be useful to assess intraspecific differences in social wasps.

Distribution of Eurasian minnows (Phoxinus: Cypriniformes) in the Western Balkans

The Eurasian minnows of the genus Phoxinus are small cyprinid species, widely distributed across Europe and Asia. Currently, there are at least 15 species in Phoxinus, with preliminary data suggesting more to be described. Despite the discernible increase in research integrating molecular phylogenetic approaches with traditional taxonomy and systematics, inter- and intraspecific relationships in the genus Phoxinus are still poorly known. The aims of this research were to: (i) compile data on the distribution of Phoxinus species in Croatia and Bosnia and Herzegovina from the sampling conducted by authors from 2006 to 2016 and from literature sources, and (ii) provide a detailed insight on distribution ranges of genetic clades and species of Phoxinus in the western Balkans. Additional 118 localities in Croatia and 8 locations in Bosnia and Herzegovina were added to already known 160 localities from the literature data. Molecular analyses of mitochondrial DNA indicate: (i) the presence of Phoxinus marsilii in Croatia (Drava drainage, the Papuk Mountain), around 260 km south of its known distribution range in Hungary, and (ii) an exceptional genetic variability of P. lumaireul in the Western Balkans.