The helminth parasites from more than 300 cetaceans stranded on the coast of England and Wales during the period 1990±1994 were identi®ed, this being the largest organized survey of cetacean parasites yet undertaken. Thirteen species of cetaceans were examined, although the majority were common (harbour) porpoises Phocoena phocoena (n = 173) and common dolphins Delphinus delphis (n = 101). The parasites found included 11 species of nematode () and two acanthocephalans (Bolbosoma capitatum, B. physeteris). The results of this survey are tabulated and each helminth species is discussed in terms of its biology and pathogenicity.

The helminth parasites from more than 300 cetaceans stranded on the coast of England and Wales during the period 1990±1994 were identi®ed, this being the largest organized survey of cetacean parasites yet undertaken. Thirteen species of cetaceans were examined, although the majority were common (harbour) porpoises Phocoena phocoena (n = 173) and common dolphins Delphinus delphis (n = 101). The parasites found included 11 species of nematode () and two acanthocephalans (Bolbosoma capitatum, B. physeteris). The results of this survey are tabulated and each helminth species is discussed in terms of its biology and pathogenicity.

Summary1. Parasites are considered to be a key driver of evolutionary processes in wild animal populations. However, assessing host-endoparasite burdens non-destructively is problematic. Collection of faecal samples can be difficult, and faecal egg counts may not always be a reliable indicator of infection intensity. 2. Here we report on endoscopy as a method for assessing natural burdens of nematode parasites Contracaecum rudolphii Hartwich, 1964, in a wild seabird, the European shag (Phalacrocorax aristotelis, L.). We aimed to measure natural individual parasite burdens and repeatability of burdens over time, and to verify that treatment with ivermectin removed parasites. 3. Endoscopy was rapid, averaging 6 min (n = 157), with no obvious adverse effects on behaviour or breeding success compared to non-endoscoped birds. 4. Nematode burdens in the oesophagus and proventriculus of conscious shags were counted and classified as absent, low, medium or high using a flexible gastroscope with a camera attachment that recorded video footage. 5. Re-assessment of worm burdens was highly accurate, with 94% of randomly selected videos (n = 50) giving identical categorical scores, and 70% of worm counts (n = 40) giving the same total or differing by only one worm. 6. All birds were parasitised by C. rudolphii. Natural burdens were significantly higher in males and in late breeders. 7. Individuals had highly repeatable categorical parasite scores over time with 65% of control birds sampled more than once (n = 17; mean interval between assessments= 10Á8 days) showing no change in scores. However, although the rank ordering of birds based on categorical scores remained constant, more finely resolved quantification indicated a slight seasonal decline in worm counts within individuals. 8. Treatment with ivermectin (4 mg kg À1 of bird weight) resulted in complete removal of parasites. There was some evidence of temporal declines in worm counts with lower doses of ivermectin, including a dose (0Á7 mg kg À1) previously shown to impact chick survival and growth. 9. Endoscopy has considerable potential for investigating individual variation and temporal changes in endoparasite burdens and drug efficacy. Applicability and limitations of this method for other host-parasite systems are discussed.

The helminth communities from ten species of lizard on seven islands in the Caribbean were sampled by collecting one hundred specimens of each species. Nine genera of parasites were identified; these included six nematodes, two digeneans and an acanthocephalan. No relationship was discernible between parasite density or abundance and island area or altitude, although dry islands tend to have fewer species of parasites. Anolis lizards of the bimaculatus and wattsi series share similar parasites with four out of nine species common to both series. The parasite community of lizards on these islands is depauperate with respect to similar surveys on the larger islands of the Greater Antilles.On three of the islands lizards were sub-sampled by collecting from moist woodland and more xeric habitats. These data suggest that differences between habitats are as significant as differences between islands in determining parasite burdens. Worm burdens of the commonest parasite species, T. cubensis, increased monotonically with host body size and no evidence was found to suggest that these parasites affect either host survival or fecundity. The sex-ratio of this species correlated with mean abundance of the parasite, with females the dominant sex on islands or in habitats where the parasite was common. This pattern may reflect haplodiploid sexual determination in this species.

Between 1 January 1992 and 31 December 1995, 73 of 487 (15%) juvenile northern elephant seals (Mirounga angustirostris) that stranded along the central California coastline and were transported to a rehabilitation center had similar clinical signs. These signs included anorexia, depression, dehydration, and epistaxis, and were accompanied by a neutrophilia. Coagulation assays on five of these animals indicated all five were in a state of disseminated intra‐vascular coagulation. Sixty‐five of the 73 animals died, and post‐mortem examination revealed heavy burdens of Otostrongylus circumlitas in the right ventricle and atrium of the hearts and pulmonary arteries, with occasional nem‐atodes in the bronchi and bronchioles. Histologic examination of 33 of these seals showed multiple pulmonary thromboses associated with a suppurative arteritis and occasionally intravascular nematodes, suggesting disseminated intravascular coagulation triggered by an arteritis may be important in causing mortality of elephant seals infested with O. circumlitus. This pathology, combined with the observation that death of juvenile northern elephant seals infected with O. circumlitus usually occurs prior to the parasite reaching reproductive maturity, suggests this is a relatively recent host‐parasite association.