Intestinal helminth fauna of bottlenose dolphin Tursiops truncatus and common dolphin Delphinus delphis from the western Mediterranean.

We report on the intestinal helminth fauna of 15 bottlenose dolphins Tursiops truncatus and 6 short-beaked common dolphins Delphinus delphis from the western Mediterranean. Eight helminth species were found in bottlenose dolphin, i.e., the digeneans Synthesium tursionis, Brachycladium atlanticum, and Pholeter gastrophilus, the nematode Anisakis sp., and the cestodes Tetrabothrius forsteri, Diphyllobothrium sp., Strobilocephalus triangularis, and tetraphyllidean plerocercoids. Brachycladium atlanticum, S. triangularis , and tetraphyllidean plerocercoids are new host records. No T. forsteri had previously been reported in Mediterranean bottlenose dolphins. Three species of helminths were recorded in the common dolphin, i.e., the digenean Synthesium delamurei (which was a new host record), and the cestodes T. forsteri and tetraphyllidean plerocercoids. The intestinal helminth communities of bottlenose and common dolphins are depauperate, similar to that of other cetacean species, but those from bottlenose dolphins harbored a higher number of helminth species. This study supports the notion that oceanic cetaceans, such as common dolphins, have a comparatively poorer helminth fauna than that of neritic species, such as bottlenose dolphins, because the likelihood of parasite recruitment is decreased.

Cestodes from Hector's beaked whale ( Mesoplodon hectori ) and spectacled porpoise ( Phocoena dioptrica ) from Argentinean waters.

Single individuals of 2 little-known cetacean species, Mesoplodon hectori and Phocoena dioptrica , stranded and died on the coast of Argentina (Buenos Aires and Chubut provinces, respectively) and were studied for the presence of helminths. The cestodes found were described and illustrated using light microscopy. The following cestode taxa were recovered: Tetrabothrius ( Tetrabothrius ) hobergi n. sp. (several fragmented specimens, at least 1 gravid) and Tetrabothrius ( s.l. ) sp. 1 (several fragmented immature specimens) from M. hectori , and Tetrabothrius ( s.l. ) sp. 2 (single fragmented immature specimen) and 2 morphotypes of tetraphyllidean larvae from P. dioptrica. Tetrabothrius ( T. ) hobergi n. sp. can be distinguished from Tetrabothrius ( T. ) forsteri by the greater number of testes and larger eggs and oncospheres, from Tetrabothrius ( T. ) curilensis by the smaller testes and vitellarium, the shape and size of the ovary, and the larger oncospheres and longer embryonic hooks, and from Tetrabothrius ( T. ) sp. from Ziphius cavirostris by the narrower strobila, smaller scolex, and smaller number of testes. The generic designations of Tetrabothrius ( s.l. ) sp. 1 and Tetrabothrius ( s.l. ) sp. 2 were based on the scolex morphology. Tetrabothrius ( s.l. ) sp. 1 is closest to Tetrabothrius ( T. ) forsteri and Tetrabothrius ( Biamniculus ) innominatus based on the number of testes, while the scolex size of Tetrabothrius ( Tetrabothrius ) sp. 2 is within the variability range reported for Tetrabothrius ( T. ) forsteri . More definite identification of the 2 species was not possible due to the condition of the available material. The present study provides the first descriptions of cestodes from M. hectori and P. dioptrica , thus enriching the knowledge regarding the helminths of insufficiently studied marine mammals.

Balaenophilus manatorum (Ortíz, Lalana and Torres, 1992) (Copepoda: Harpacticoida) from loggerhead sea turtles, Caretta caretta, from Japan and the western Mediterranean: amended description and geographical comparison.

The ectoparasitic harpacticoid copepod, Balaenophilus manatorum (Ortíz, Lalana and Torres, 1992) (syn. Balaenophilus umigamecolus Ogawa, Matsuzaki and Misaki, 1997), has been reported on 3 species of marine turtles from the Pacific and the Mediterranean and from the West Indian manatee off Cuba in the Caribbean. The 3 available descriptions of this species were made using light microscopy. In this paper, we provide an amended description of B. manatorum using scanning electronic microscopy (SEM) for specimens in the collection from which B. umigamecolus was originally described. This material was collected from 1 loggerhead sea turtle, Caretta caretta, from Japan. The use of SEM allowed us to add several new microcharacters to the original description but, more importantly, allowed us to correct a number of the traits originally described. Some of the corrections could affect the interpretation of putative homology and variability of characters among populations of B. manatorum. A SEM comparison of specimens of B. manatorum from loggerheads from Japan and the western Mediterranean suggested the existence of morphological stasis between these populations. However, there were apparent meristic differences with a recently published description of this species from olive ridleys, Lepidochelys olivacea, in Mexico. Although B. manatorum is currently considered as a single, widespread taxon, the possibility that it actually represents a species complex deserves further attention.

Comparison of a manual and an automated method to estimate the number of uterine eggs in anisakid nematodes: to Coulter or not to Coulter. Is that the question?

Studies reporting numbers of eggs in vagina and utero in nematodes often give little information of the technique used for the estimations. This situation hampers comparison among studies, because, so far, differences in estimations provided by different techniques have not been assessed. This note examines whether a manual method based on visual counts in aliquots and an automated method using a Coulter counter yield equivalent estimations of egg numbers in vagina and utero of 3 anisakid nematode species (Anisakis simplex, Pseudoterranova decipiens, and Contracaecum osculatum). The number of eggs from 50 females per nematode species was estimated using both techniques. The automated and manual methods yielded similar egg counts (correlation coefficients >0.9 in the 3 species), but the methods were not always statistically equivalent. The automated method was more precise and seemed less dependent on egg density, whereas the manual method was less time-consuming (contrary to previous perceptions) and less expensive. Despite the higher precision of automated counts, the manual technique seemed to produce similar estimates; thus, it may be particularly useful in developing countries where nematode parasitism is prevalent in humans and domestic animals, but scientific resources are limited.

Gastrointestinal helminths of Risso's dolphin Grampus griseus from the Western Mediterranean.

The gastrointestinal helminth fauna of 17 Risso's dolphins Grampus griseus (Cuvier, 1812) from the Western Mediterranean was analysed. Five helminth species were found. Adults and juveniles of Hadwenius delamurei were collected from the duodenum of 7 animals. Adults were located significantly more anteriorly than juveniles, which is compatible with a previous hypothesis that species of Hadwenius undergo an ontogenetic migration towards the anterior duodenum. Eggs from Pholeter gastrophilus appeared in 1 small cyst in the main stomach. Adults of Tetrabothrius forsteri and Trigonocotyle globicephalae were collected from the duodenum of 1 and 4 individuals, respectively. Metacestodes, Scolex pleuronectis, were found in the liver, pancreas, pyloric stomach and intestine of 13 individuals. The most favored locations were in the mucosa of the terminal colon and in anal crypts. It is likely that worms select these locations to reach the mesenteries and blubber of the anogenital area, where S. pleuronectis might become Monorygma and/or Phyllobothrium. Two individuals of Stenurus globicephalae occurred in the intestine of 1 individual, and were probably swallowed accidentally. The intestinal helminth communities of Risso's dolphin are depauperate. The parasite species found also occur in other oceanic cetaceans from the Western Mediterranean. However, H. delamurei and T. globicephalae are only shared with pilot whales Globicephala spp., which are phylogenetically closely related to Risso's dolphins.