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The article informs that the current issue of the journal is comprised of papers presented in the "Crossing boundaries and building bridges: integrative zoology" symposium held in Montréal, Quebec from May 25-29, 2015 along with information on its editors Angela L. Shamchuk and Heath A. MacMillan.

Stable-isotope ratios are increasingly being used to examine ecological questions pertaining to dietary choices, physiological status, and animal migration. It has been shown that animal tissues reflect the isotopic signature present in food, altered by a small reproducible fractionation value. The average diet–tissue discrimination for δ13C and δ15N is approximately 1‰and 3‰, respectively, although the degree of diet–tissue discrimination may be affected by a range of factors and vary between organisms and tissue types. Although the average δ34S is approximately zero, the sulfur diet–tissue discrimination values have only been determined for a few organisms. It is necessary to determine accurate diet–tissue discrimination values between tissue and dietary components to have confidence in any food-web study or determination of diet quality. In this paper, we determine carbon, nitrogen, and sulfur diet–tissue discrimination values for whole blood, liver, skeletal muscle, heart, brain, and fat (carbon only) from adult mice (Mus musculus L., 1758) equilibrated on three diets with unique isotopic signatures for carbohydrate carbon and for protein carbon, nitrogen, and sulfur. These data will aid researchers in choosing tissues to be used to examine food-web changes over time. [ABSTRACT FROM AUTHOR]

Four chordate characters — dorsal hollow nerve cord, notochord, gill slits, and endostyle — are compared morphologically, molecularly, and functionally with similar structures in hemichordates to assess their putative homologies. The dorsal hollow nerve cord and enteropneust neurocord are probably homoplasies. The neurocord (= collar cord) may be an autapomorphy of Enteropneusta that innervates a unique pair of muscles, the perihemal coelomic muscles. Despite the apparent lack of organ-level homology, chordates and enteropneusts share a common pattern of neurulation that preserves a "contact innervation" between neuro- and myo-epithelia, which may be the primitive deuterostome pattern of neuromuscular innervation. The chordate notochord and hemichordate stomochord are probably homoplasies. Other potential notochord antecedents in hemichordates are examined, but no clear homolog is identified. The comparative morphology of notochords suggests that the "stack-of-coins" developmental stage, retained into adulthood only by cephalochordates, is the plesiomorphic notochord form. Hemichordate and chordate gill slits are probably homologs, but only at the level of simple ciliated circular or oval pores, lacking a skeleton, as occur in adults of Cephalodiscus spp., developmentally in some enteropneusts, and in many urochordates. Functional morphology, I125-binding experiments, and genetic data suggest that endostylar function may reside in the entire pharyngeal lining of Enteropneusta and is not restricted to a specialized midline structure as in chordates. A cladistic analysis of Deuterostomia, based partly on homologs discussed in this paper, indicates a sister-taxon relationship between Urochordata and Vertebrata, with Cephalochordata as the plesiomorphic clade. [ABSTRACT FROM AUTHOR]

The last comprehensive reviews of ecology and natural history of ascidians were included in the excellent 1971 publication by Millar on the biology of ascidians and the 1991 treatise on New Caledonia ascidians by Monniot, Monniot, and Laboute. Several hundred papers have been published since that time, greatly expanding our knowledge of environmental tolerances and responses to increasing levels of anthropogenically derived toxins in marine waters, energetics and feeding strategies, predator–prey relationships, competition both intra- and inter-specific that include many studies of self–nonself recognition in colonial species, modes and environmental regulation of reproduction and development, symbionts, natural-product chemistry as antifouling and antipredator defenses, and dispersal mechanisms. The relatively new field of molecular genetics is revealing the presence of cryptic species and is helping to determine the origin of anthropogenically transported individuals, an important and growing problem that affects natural ecological relationships in marine communities worldwide. We are learning more about the difficult-to-study abyssal and Antarctic species. There have been great advances in our understanding of the importance in open-ocean food webs of the planktonic Appendicularia and Thaliacea. Also included in this review is a brief discussion of recent work on the Cephalochordata and Hemichordata. [ABSTRACT FROM AUTHOR]

Our paper on spiders provides an early demonstration of the power of DNA barcoding; we believe that its conclusions will prove scalable to all eukaryotes. We further anticipate that the "Barcode of Life" movement will soon lead to automated systems for species identification and discovery. However, we emphasize that these systems will operate within a Linnaean framework and that collaborations between molecular and morphological taxonomists are critical. [ABSTRACT FROM AUTHOR]