Laboratory and field experiments were conducted on the island of Hawaii from 1977—1980 in an effort to determine the impact of avian malaria on the forest birds. At 16 study sites from sea level to tree line in mesic and xeric habitat, birds were captured and bled to determine the host and altitudinal distribution of blood parasites. In the laboratory, six bird species were challenged with malarial parasites to measure host susceptibility. Distributions, activity cycles, and transmission potentials of malarial parasite vectors were also analyzed. One species of Plasmodium was present from sea level to tree line, concentrated in the mid—elevational ranges in the ecotonal area where vectors and native birds had the greatest overlap. Native forest birds were: (a) more susceptible to malaria than were introduced species; (b) most likely to have malaria during the nonbreeding, wet season; (c) found ranging lower in xeric than in mesic forests; and (d) found to have a lower prevalence of malaria in xeric forests. Temporal as well as elevational differences in prevalence and parasitemia levels of wild birds were apparent throughout the annual cycle, a result of differing host and parasite responses to biotic and abiotic factors. Avian malaria probably did not reach epizootic proportions on Hawaii until after ≈1920. However, since that time it has had a negative impact on the population dynamics of the native forest birds and is today a major limiting factor, restricting both abundance and distribution of these species on the island. In response, a number of native bird species have developed immunogenetic and behavioral responses that reduce the impact of the parasite on host populations.

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Of 1142 fish (68 species) examined, 140 (21 species) yielded blood parasites. Overall incidence was much higher at St. Andrews, N.B., than at Woods Hole, Mass., as was the variety of fish harbouring haematozoa — 15 species (46.9%) in the former case, but only 4 (9.3%) in the latter.Trypanosoma rajae Laveran and Mesnil and Cryptobia bullocki Strout are new records for Canada, Haemogregarina delagei Laveran and Mesnil has not previously been reported from the western side of the Atlantic, and the present finding of an undesignated species of Haemohormidium Henry (a babesioid genus with which Babesiosoma Jakowska and Nigrelli is now synonymized) is the first from North American marine fish. New hosts and localities are listed for Haemogregarina bigemina Laveran and Mesnil, H. platessae Lebailly, H. aeglefini Henry, H. myoxocephali Fantham et al., and certain unidentified haemogregarines. Haemogregarina urophysis Fantham et al. is relegated to synonymy with H. aeglefini; and H. gadi pollachii Henry and H. pollachii Henry are discarded as nomina nuda. Myxosporidians of the genus Kudoa are reported (presumably as contaminants derived from slit muscle) in blood films from six hosts.Haemogregarina mavori n.sp., from Passamaquoddy Bay Macrozoarces americanus, averages 6.4 × 2.9 μ. Broadly oval to reniform and with a large, subterminal nucleus, it is found in erythrocytes that are shorter and broader than normal and exhibit marked nuclear displacement.Piscine erythrocytic necrosis (PEN) is a degenerative infection responsible for massive red blood cell destruction in Gadus morhua (Passamaquoddy Bay) and also found in Liparis atlanticus (Kent Island, N.B.) and Myoxocephalus octodecemspinosus (Portsmouth Harbor, N.H.). A distinctive inclusion body formed in the cytoplasm of infected red cells recalls similar bodies associated with Pirhemocyton Chatton and Blanc and Toddia França. Erythrocyte nuclei disintegrate with the liberation of viruslike particles formed in vesicles within them.

Thirty-six immature examples of the serranid Epinephelus 71ierrc~ Bloch were collected from coral pools a t Aneityum (New Hebrides) and Maliuluva Islet (Fiji), on four occasions from 1952 to 1951. The gills of all of them were infected \\,it11 Diplectnwr~rt~ 71zelnnesie~~sis 11. sp., the closest Icnown relatives of which parasitize allied hosts in Japan (D. epirtepheli Yanlaguti) and Celebes (D. serrar~i Yamaguti). The South Pacific species resembles D. serrnni but differs from D. epinephe!i in lacking a conspicuous ejaculatory bulb and in having a transversely positioned ovary thc elongate terminal portion of which enfolds thc right caecum. I t is distinguisherl from both these species by its markedly s~iialler size (217 to 500 p by 66 to 117 p , a v . , 366 by 92 p) and the structure of the squamodiscs, \vhich ha1.c nine concentric ro\\-s of rodlets, the four innermost ones forming complete circlets. Can. J. 2001. 36 (19.58) Can. J. Zool. Downloaded from www.nrcresearchpress.com by DUKE UNIV BOX 90187 on 10/01/12For personal use only. *Termination of specific name enlended by Sproston (6). Originally Lepidoles fluvialilzcs Johnston and Tiegs, then Dipleclanzrnzflzr.~ialzlis (J. and T.) Pr~ce.

Trichodina elizabethae n. sp. (which is commonly hyperparasitized by the suctorian Endosphaera engelmanni Entz), T. galyae n. sp., and T. domerguei (Wallengren) saintjohnsi n. subsp. are described from Newfoundland waters; the first two from the radiated shanny and lumpfish respectively, and the last from the mailed sculpin, lumpfish, and shorthorn sculpin. T. jarmilae n. sp. parasitizes the sea raven in the Bay of Fundy, New Brunswick. In both provinces, T. cottidarum Dogiel, sensu lato, occurs on shorthorn and longhorn sculpins. Two species of fish from brackish pools (the threespine stickleback in both areas; the mummichog in the Bay of Fundy) are often heavily parasitized by T. tenuidens Fauré-Fremiet. All the ciliates referred to were collected from the gills of their hosts, only two of which bore peritrichs other than trichodinids. One of these, Caliperia brevipes Laird, is found on the little skate in the Bay of Fundy and has been described elsewhere. The other, Scyphidia arctica Zhukov, is now reported from the longhorn sculpin in Newfoundland. Only five (16%) of 31 species of marine fish from Newfoundland bore trichodinids, as compared with nine (35%) of 26 from New Brunswick. However, four of the latter group had extremely light or sporadic infestations. Three of the rest, showing high incidence and heavy to extremely heavy infestations, were sculpins (Cottidae), as were three of the five Newfoundland hosts. Thus, while information is accumulating to suggest that marine fish trichodinids find optimum environmental conditions where mean seawater temperatures are not extreme (neither very warm nor very cold), certain fish are evidently more prone to infestation than others. This may well be due to varying ecological vulnerability to parasitization rather than to the operation of host specificity, an important question which, like that of environmental tolerances, merits early experimental attention. The paper includes a list of 61 species of Trichodina and the closely related Tripartiella and Trichodinella now known from marine and euryhaline fish, their validity being assessed on the basis of technique and the taxonomic criteria used.