First record of a hagfish anchored to a living bottlenose dolphin in the Mediterranean Sea

An unusual observation of a hagfish ( Myxine glutinosa ) anchored to a living bottlenose dolphin ( Tursiops truncatus ) was documented in an encounter with a group of about 80 dolphins during an ongoing long-term research program on cetaceans in the central Mediterranean Sea, Italy. The body of the hagfish was observed extruding from the blowhole of the bottlenose dolphin showing a stereotypical surfacing–breathing pattern. The observation lasted 2h; photo-identification, acoustic, and behavioral data were collected. Succorant behaviors (i.e., "standing by") from conspecifics and overlapping vocalizations during social phases were recorded. The dolphin was encountered again after 1 month in the same area without the hagfish, apparently in healthy conditions

Occurrence and spatio-temporal distribution of sperm whale (Physeter macrocephalus) in the submarine canyon of Cuma (Tyrrhenian Sea, Italy)

1. Boat surveys aimed at studying sperm whales in the Tyrrhenian Sea were conducted between 2002 and 2011. During 768 daily surveys, a total effort of 32 602km was achieved within an area of 8800km2 resulting in 92 encounters with 229 sperm whale individuals. 2. Average encounter rates of sperm whales was 0.5 groups per 100km2, with a higher concentration in the vicinity of the submarine canyon of Cuma, confirming the importance for the species of this small hotspot in the Mediterranean Sea. 3. Encounter rates increased with increasing distance from the coast. It is possible that the intense boat traffic and anthropogenic disturbance in the area may be moving animals away from the coast leading to habitat loss. 4. The species–habitat relationship documented in this study has implications for conservation

Analysis of the natural markings of Risso’s dolphins (Grampus griseus) in the central Mediterranean Sea

Risso’s dolphins are known for the persistency of their natural markings, possibly due to the loss of pigment during the healing process of skin wounds. Nonetheless, the actual longevity and reliability of each mark type has never been assessed. In this paper, we used photographs to investigate the etiology of skin marks in the species, analyze their distribution and temporal variability, and discuss implications for photo identification. Nineteen mark types were described on the dorsal fin of Risso’s dolphin, including 2 new to the literature: the snakelike mark and the protruding fat. Longevity of skin marks ranged from 6 years for the protruding fat to several decades for scrapes and dots. Persistent and reliable marks were notch, tooth-rake, and thick single and parallel scrapes. Mark change was sufficiently low that all mark types could be used for photo identification, provided that backlit or underexposed images were discarded as photographs taken under suboptimal light conditions proved to be unreliable. Finally, mark distribution and variability were unequal between age classes; juveniles were less marked and showed a higher rate of mark change than older individuals so that, even if they possessed enough notches to be classified as reliably marked, they could be confidently matched over a time interval of up to 3 years