A Transient Developmental Background Finding in the Retina Observed in Neonatal Dogs in Juvenile Toxicology Studies

In a juvenile toxicology program, an unexpected finding of vacuolation of inner nuclear, ganglion cell, and nerve fiber layers of the retina was observed microscopically in routine Davidson’s fixed and hematoxylin and eosin–stained tissue sections of eyes in beagle dogs at approximately 5 weeks of age. There was no necrosis or degeneration of the affected cells and no associated inflammation. Fluorescein angiography revealed no vascular leakage. Optical coherence tomography (OCT) indicated swollen cells in the same layers of the retina as observed at light microscopic examination. Transmission electron microscopy revealed that the retinal vacuolation likely was consistent with intracellular swelling of amacrine, horizontal, and/or bipolar cells of the inner nuclear layer as affected cells had an expanded cytoplasm but contained normal nucleus and organelles. As assessed by animal behavior and full-field electroretinography, the retinal vacuolation appeared to have no impact on visual function. Retinal vacuolation was seen in approximately 40% of dogs at 5 weeks of age using OCT and/or light microscopic examination. Because the change was transient and age related, did not result in degenerative retinal changes, and was not present in dogs older than 5 weeks of age, it was considered a background developmental observation in beagle dogs.

Morphology, molecular and systematic analyses of Bychowskyella (Monogenea: Dactylogyridae) in siluriform fish from India

Three species of genus Bychowskyella Akhmerov (1952), i.e. B. fossilisi Majumdar & Agarwal, 1989, B. tchangi Gusev, 1976 and B. wallagonia (Jain, 1959a) Gusev, 1961, were found to parasitize the gill filaments of siluriform fish in India. This redescription based on light microscopic examination of B. fossilisi, B. tchangi and B. wallagonia provides detailed taxonomic data for these species. We also amplified the 18S ribosomal RNA gene to evaluate the phylogenetic relationships of these three species. The morphological and genetic profiles confirmed the validation and taxonomical relationships of the above-mentioned species belonging to the genus Bychowskyella.

Kinorhyncha from the Iberian Peninsula: new data from the first intensive sampling campaigns

Data are presented from the first intensive sampling of Kinorhyncha around the Iberian Peninsula over a 21-year periodfrom 1990 to 2011, from 81 sites mostly in less than 100 m water depth. Light-microscopic examination of approximately2000 specimens yielded 11 genera and 29 species, only 11 of which were previously recorded from peninsular waters. Thebalance comprises ten new species records for the peninsula and eight new species that are yet to be described. The mostspeciose genus is Echinoderes, with ten species, two of them new, followed by Pycnophyes (nine species, three new).There are two species of Antygomonas (one new), and one each for the genera Campyloderes, Centroderes, Condyloderes(one new), Dracoderes, Meristoderes, Semnoderes, Kinorhynchus (one new), and Paracentrophyes. The most ubiquitousspecies in the samples, appearing at nearly all localities was Pycnophyes dentatus, newly recorded for the Iberian Penin-sula and found at nearly all sampled localities and in high numbers. Echinoderes cantabricus, E. hispanicus and E. dujar-dinii also have a wide distribution along both Atlantic and Mediterranean coasts. Known information on diversity, biogeography and ecology (depth, sediment and abundance) is discussed.