Multilocus species delimitation in Mesoamerican Scaptotrigona stingless bees (Apidae: Meliponini) supports the existence of cryptic species

Accelerating taxonomic knowledge and making accurate species identifications are critically important given the current biodiversity crisis, particularly in biodiversity hotspots such as Mesoamerica. Objective species delimitation that reduces investigator‐driven bias is fundamental to the establishment of appropriate conservation strategies, above all in managed species. Previous morphological and molecular studies on three managed stingless bee species of the genus Scaptotrigona distributed in Mexico (S. mexicana, S. pectoralis and S. hellwegeri) suggested that both S. mexicana and S. hellwegeri are cryptic species complexes. Herein we tested species delimitation by analysing sequence information of five markers (two mitochondrial: cox1 and 16S, and three nuclear: ITS1, EF1‐α, ArgK) within a Bayesian coalescent framework to test the putative species. We obtained two different hypotheses using a Generalized Mixed Yule Coalescent (GMYC) model: four (cox1) and six (16S) species. After the species validation step with the Bayesian species‐delimitation analysis (BPP), we suggest that only S. mexicana is a complex of two species with different distribution (along the Pacific and the Atlantic coasts, respectively). We highly recommend avoiding colony exchange between geographical regions in order to conserve the genetic integrity of both taxa.     

Habitat heterogeneity and mammalian predator–prey interactions

• 1 In predator–prey theory, habitat heterogeneity can affect the relationship between kill rates and prey or predator density through its effect on the predator's ability to search for, encounter, kill and consume its prey. Many studies of predator–prey interactions include the effect of spatial heterogeneity, but these are mostly based on species with restricted mobility or conducted in experimental settings.
• 2 Here, we aim to identify the patterns through which spatial heterogeneity affects predator–prey dynamics and to review the literature on the effect of spatial heterogeneity on predator–prey interactions in terrestrial mammalian systems, i.e. in freely moving species with high mobility, in non‐experimental settings. We also review current methodologies that allow the study of the predation process within a spatial context.
• 3 When the functional response includes the effect of spatial heterogeneity, it usually takes the form of predator‐dependent or ratio‐dependent models and has wide applicability.
• 4 The analysis of the predation process through its different stages may further contribute towards identifying the spatial scale of interest and the specific spatial mechanism affecting predator–prey interactions.
• 5 Analyzing the predation process based on the functional response theory, but separating the stages of predation and applying a multiscale approach, is likely to increase our insight into how spatial heterogeneity affects predator–prey dynamics. This may increase our ability to forecast the consequences of landscape transformations on predator–prey dynamics.

     

Long-term variation in algal intertidal floras

A long-term study (1973-9) was made of the intertidal floras of two headlands, one exposed to the ocean, the other in a bay. Many algal species varied erratically in frequency or occurrence from year to year, apparently due to local chance causes, but in some years many species showed reductions in frequency. In these years the changes in the flora appear to be associated with sand movements, which are possibly due to locally damaging storms. Recovery of the floras follows these depressions, but it is stressed that this recovery depends on the existence of a reservoir of spore-producing plants which in turn depends on the maintenance of good water quality in the sea. The naturally occurring variations in floras are greater than are any induced by a low volume well-treated sewerage outfall, except in the immediate area of the outfall.     

A subtidal transect in Jervis Bay,New South Wales

Long-term variations in the intertidal algal flora of the entire rock platform at Plantation Point, Jervis Bay, are described by May (1981). The study now reported presents similar long-term changes in the flora of a subtidal region of the same headland, observed within the same period of time. This first detailed report of subtidal macroalgal communities in New South Wales describes a several-year study of the benthic communities along a transect in the upper sublittoral region of a rocky headland at Plantation Point, Jervis Bay. Eighty-nine species of algae were recorded, five of which were previously unrecorded for New South Wales. The area studied is dominated by the large brown algae Ecklonia radiata and Phyllospora comosa, large areas of which were cleared periodically by storms. Turf, shade and crustose coralline algal communities also were present. Storms, seasonal variation and longer term changes all affected the abundance and distribution of the algal species growing along the transect and hence the floristic composition of the area.     

Characterization of microsatellite loci for five members of the minnow family Cyprinidae found in the Sacramento–San Joaquin Delta and its tributaries

Two microsatellite‐enriched libraries [(CAGA)_n, (TAGA)_n] were constructed using pooled DNA from three cyprinid species native to the Sacramento–San Joaquin Delta of California: Sacramento splittail (Pogonichthys macrolepidotus); Sacramento pikeminnow (Ptychocheilus grandis); and tui chub (Siphateles bicolor). Primers were designed for 105 loci and tested for levels of polymorphism in five cyprinid species found in the Delta: Sacramento splittail, Sacramento pikeminnow, tui chub, hitch (Lavinia exilicauda), and Sacramento blackfish (Orthodon microlepidotus). Fifty‐one loci were polymorphic for at least one species and 31 loci were polymorphic for multiple species. The number of polymorphic loci per species ranged from 16 to 26.