Search results for "cetacea"
showing 10 items of 77 documents
Status of Corynosoma (Acanthocephala: Polymorphidae) based on anatomical, ecological, and phylogenetic evidence, with the erection of Pseudocorynosom…
2006
The possession of genital spines has been considered as a key taxonomic trait to differentiate Corynosoma from other genera of the Polymorphidae. However, Corynosoma currently consists of 2 groups of species with clear ecological and morphological divergences: the "marine" group (with ca. 30 species) infects mammals and piscivorous birds in the marine realm, whereas the "freshwater" group (with ca. 7 species) infects waterfowl in continental waters. Species from these groups differ in shape of body and neck, trunk spination, lemnisci length and shape, testes arrangement, and number and shape of cement glands. We tested whether species from these 2 groups formed a monophyletic assemblage bas…
Presence of genital spines in a male Corynosoma cetaceum Johnston and Best, 1942 (Acanthocephala).
2002
We collected 83 females and 80 males of Corynosoma cetaceum from 2 common dolphins, Delphinus delphis, collected in northern Patagonia (Argentina). Worms were most similar to specimens collected in other South American localities. However, 1 male had 2 spines adjacent to the genital pore and isolated from the rest of body spines. This finding confirms the recent reassignment of C. cetaceum to Corynosoma. Absence of genital spines is suggested to be avoided as the sole criterion to exclude specimens from Corynosoma or Andracantha.
Epidemiological pattern of tattoo skin disease: a potential general health indicator for cetaceans
2009
The presence of tattoo skin disease (TSD) was examined in 1392 free-ranging and dead odontocetes comprising 17 species from the Americas, Europe, South Africa, New Zealand and Greenland. We investigated whether TSD prevalence varied with sex, age and health status. TSD was encountered in cetaceans from the Pacific and Atlantic Oceans as well as in those from the North, Mediterranean and Tasman Seas. No clear patterns related to geography and host phylogeny were detected, except that prevalence of TSD in juveniles and, in 2 species (dusky dolphin Lagenorhynchus obscurus and Burmeister’s porpoise Phocoena spinipinnis), in adults was remarkably high in samples from Peru. Environmental factors …
Monitoring the habitat use of common Bottlenose Dolphins (Tursiops truncatus) using passive acoustics in a Mediterranean marine protected area
2014
The Mediterranean Tursiops truncatus subpopulation has been classified as Vulnerable on the IUCN Red List because of its decline. This species in coastal areas is exposed to a wide variety of threats: directed kills, bycatch, reduced prey availability caused by environmental degradation and overfishing, habitat degradation including disturbances from boat traffic and noise. Despite the increase in boat traffic in the Mediterranean Sea, the effect on T. truncatus’ habitat use has been studied in little detail and few data have been published. This study represents the first attempt to characterise spatial and temporal habitat use by T. truncatus and its relation to boat traffic in the Isole …
Sometimes Sperm Whales (Physeter macrocephalus) Cannot Find Their Way Back to the High Seas: A Multidisciplinary Study on a Mass Stranding
2011
BackgroundMass strandings of sperm whales (Physeter macrocephalus) remain peculiar and rather unexplained events, which rarely occur in the Mediterranean Sea. Solar cycles and related changes in the geomagnetic field, variations in water temperature and weather conditions, coast geographical features and human activities have been proposed as possible causes. In December 2009, a pod of seven male sperm whales stranded along the Adriatic coast of Southern Italy. This is the sixth instance from 1555 in this basin.Methodology/principal findingsComplete necropsies were performed on three whales whose bodies were in good condition, carrying out on sampled tissues histopathology, virology, bacter…
Influence of environmental factors on small cetacean distribution in the Spanish Mediterranean
2008
Habitat distribution models are one of the most up to date methods to study the habitat usage of wildlife populations. They allow animal distribution to be related to environmental features and also the prediction of the distribution of animals based on this relationship. Seasonal aerial surveys were conducted in central Spanish Mediterranean waters from June 2000 to March 2003 to obtain information on the distribution of cetacean species. Data from the three most common cetacean species (striped dolphin,Stenella coeruleoalba, bottlenose dolphin,Tursiops truncatus, and Risso's dolphin,Grampus griseus) were related, using generalized linear models, to local environmental features: depth, slo…
An insight into the status of the striped dolphins, Stenella coeruleoalba, of the southern Tyrrenian Sea
2007
Drift-nets are known to result in high incidental catches of some cetacean species. Despite a UN moratorium on their use in the high seas and a ban in the Mediterranean by all European Union countries, including Italy (EC Reg. 1239/98), some fisheries continue to operate illegally. In 2002 and 2003 three line-transect surveys were conducted in the southern Tyrrhenian Sea around the Aeolian archipelago. These transects were designed to assess the presence, distribution and population size of cetacean species likely to be affected by accidental captures in this area. Data were only sufficient to estimate abundance for the striped dolphin. The best estimate (and first such estimate for this ar…
Hadwenius tursionis (Marchi, 1873) n. comb. (Digenea, Campulidae) from the bottlenose dolphin Tursiops truncatus (Montagu, 1821) in the western Medit…
1994
The taxonomic position of Synthesium tursionis (Marchi, 1873) (Digenea, Campulidae) is revised, based on material from 147 worms from four bottlenose dolphins Tursiops truncatus stranded off the Comunidad Valenciana (Spanish western Mediterranean). The species is transferred to Hadwenius, as H. tursionis n. comb., and characterised by a high length/width ratio of the body, spinose cirrus and unarmed metraterm. Synthesium, a monotypic genus, becomes a synonym of Hadwenius. The intraspecific variation of some morphological traits is briefly discussed.
A new species of the genusCrassicaudaLeiper et Atkinson, 1914 (Nematoda: Spiruroidea) from the penis ofGlobicephala melas(Traill, 1809) (Cetacea: Glo…
1990
The examination of a male long-finned pilot whale (Globicephala melas) stranded at Cullera (Spanish Mediterranean coast) resulted in the finding of nematodes of the genus Crassicauda parasitising the penis. Pathologies associated with these worms were observed and are described here. The morphometric and morphological study of these helminths revealed that they represent a new species, Crassicauda carbonelli n. sp., which differs from other species of the genus Crassicauda in body size, cephalic morphology and spicule size in the males. Crassicauda sp. described by Dollfus (1968) must be ascribed to C. carbonelli n. sp. The taxonomy, morphometric variability of the eggs, site in the hosts, …
Dolphin morbillivirus epizootic resurgence, Mediterranean Sea
2008
In July 2007, > 100 striped dolphins, Stenella coeruleoalba, were found dead along the coast of the Spanish Mediterranean. Of 10 dolphins tested, 7 were positive for a virus strain closely related to the dolphin morbillivirus that was isolated during a previous epizootic in 1990.