Cetacean interactions with fishing gear are reported regularly and most frequently involve incidental capture. However, limited records exist related to depredation resulting in fishing gear ingestion. Here, we present cases of depredation resulting from ingestion of gill-net parts and larynx strangulation documented for the first time in a cetacean species. The bottlenose dolphin (Tursiops truncatus) is the only 392 -DURAS GOMERČIĆ ET AL.: LARYNX STRANGULATION IN TURSIOPS 393 resident species in the Adriatic Sea, where small-scale commercial and private fisheries use gill nets throughout the year. A total of 120 dead-stranded bottlenose dolphins found along the Croatian coast of the Adriatic Sea were examined from 1990 to March 2008; 12 of them (10%) were affected by larynx strangulation with gill-net parts. The larynx of all affected animals showed at least one of the following pathological changes: edema, mucosal injury, and hypergranulation. In the majority of cases, it was a chronic condition. Larynx strangulations were found only in adult animals and appeared more often in animals with reduced ability to catch free-swimming prey.

Summary The structure of the adrenal gland was studied in 11 bottlenose dolphins (Tursiops truncatus), and five striped dolphins (Stenella coeruleoalba). These species are legally protected in Croatia. All examined animals died of natural causes and were found stranded along eastern Adriatic coast. In both species the adrenal gland consists of a cortex and a medulla; the cortex is divided into three zones. Whereas in the bottlenose dolphin, there is a zona arcuata which contains columnar cells arranged in the form of arches; in the striped dolphin this zone is replaced by zona glomerulosa containing rounded clusters of polygonal cells. In both species, the zona fasciculata consists of radially oriented cords of polygonal cells, whereas in zona reticularis cells are arranged in branching and anastomosing cords. The adrenal medulla in both species contains dark, epinephrine‐secreting cells and light norepinephrine‐secreting cells. Epinephrine‐secreting cells are localized in the outer part of the medulla, whereas norepinephrine‐secreting cells are found in the inner part, arranged in clusters and surrounded by septa of thin connective tissue. The gland is surrounded by a thick connective‐tissue capsule, from where thick trabeculae extend towards the interior. In the bottlenose dolphin, group of cells resembling both medullar and cortical cells can be seen within the capsule; whereas only groups of cells resembling cortical cells are found within the capsule of the striped dolphin. In the bottlenose dolphin invagination of the adrenal cortex into the medulla is obvious as well as medullary protrusions extending through cortex to the connective tissue capsule.

The aim of the study was to assess the effect of litter type and environmental enrichment on the occurrence of footpad dermatitis and hock burns in broilers housed at low and high stocking densities. Chopped straw and sand were used as litter, and perches as environmental enrichment. Low and high stocking density implied 12 chickens/m 2 and 20 chickens/m 2 , respectively. The study sample was divided into four groups of 50 birds, which were observed during a six-week fattening period. A significantly higher rate of severe footpad dermatitis was recorded in the group of chickens raised on sand at high stocking density, compared with low stocking density, whereas no significant difference was found between the groups of chickens raised on straw at different stocking densities. The rate of footpad dermatitis was also significantly higher in the group of chickens raised on sand at high stocking density, compared with chickens raised on straw at the same stocking density. There were no group differences in the occurrences of hock burns and perching. However, a significant negative correlation was recorded between perching and the occurrence of footpad dermatitis and hock burns. According to the occurrence of footpad dermatitis and hock burns, the study results suggested that chopped straw and sand were equally acceptable as litter for broilers, yet sand should be avoided at high stocking densities. There was no effect of stocking density and litter type on perching, but perches as a form of environmental enrichment proved efficient in reducing the rate of footpad dermatitis and hock burns.

Morphology of the lymph nodes was examined in six bottlenose dolphins (Tursiops truncatus) and three striped dolphins (Stenella coeruleoalba) from the Adriatic Sea. All animals had been found dead in nature. One group of the nodes was taken from the tracheal branching area and was marked as bifurcational lymph node, and the other group was taken from the mesenteric root and was marked as mesenteric lymph node. Microscopic analysis showed that the lymph nodes in both dolphin species were surrounded by a connective tissue capsule comprising smooth muscle cells. The parenchyma of the mesenteric and bifurcational lymph nodes in bottlenose dolphin was divided into the peripherally situated cortex with the lymphatic nodules and diffuse lymphatic tissue, and the centrally situated medulla structured of the medullary cords separated by the medullary sinuses. These lymph nodes structurally correspond to the lymph nodes in the majority of terrestrial mammals. The mesenteric lymph node of striped dolphin also had a peripherally situated cortex and a centrally positioned medulla as the majority of terrestrial mammals. In the bifurcational lymph nodes of striped dolphin, there was a central dense lymphatic tissue with the lymphatic nodules and a peripheral less dense lymphatic tissue structured of the cell cords and sinuses. The bifurcational lymph node in striped dolphin resembled porcine lymph nodes and belonged to the inverse lymph nodes.