Avian Haemoproteidae. 22. The haemoproteids of the New World flycatchers, the Tyrannidae

GORDON F. BENNETT, JENNIFER R. CAINES, AND MADONNA WHITEWAY Department of Biology and International Reference Centre for Avian Haematozou, Memorial University of Newfoundland,

St. John's, NJZd., Canada AIB 3x9

Received August 28, 1985

BENNETT, G. F., J . R. CAINES, and M. WHITEWAY. 1986. Avian Haemoproteidae. 22. The haemoproteids of the New World flycatchers, the Tyrannidae. Can. J . Zool . 64: 774-777.

The haemoproteids of the Tyrannidae are reviewed and three new species, Haemoproteus circumnuclearis, H . souzalopesi, and H . tyranni are described.

BENNFTT, G. F., J . R. CAINES, et M. WHITEWAY. 1986. Avian Haemopoteidae. 22. The haemoproteids of the New World flyciitchers, the Tyrannidae. Can. J. Zool. 64: 774-777.

On trouvera ici la revision des haemoproteides parasites de la famille Tyrannidae. Trois nouveau especes, Haemoproteus circumnuclearis, H. souzaloposi et H . tyranni, sont decrits .

[Traduit par la Revue]

Introduction The 377 species of the Tyrannidae represent a New World

assemblage of insectivorous birds, the great majority of which are confined to the Neotropical regions with a few species extending northwards through Central America to the Nearctic. Approximately one-third of the species (126) have been examined for blood parasites and haemoproteids have been reported in 39 (Bennett et al. 1982). However, these haemo- proteid infections have not been identified to the species level and despite the relative abundance of material, no species of Haemoproteus has been described from the Tyrannidae. Over the past 15 years, a collection of tyrannid blood films from the distributional range of the family has been assembled at the International Reference Centre for Avian Haematozoa. Exami- nation of this material has indicated the presence of three new and distinctive species of haemoproteids which are herein described as Haemoproteus circumnuclearis, H. souzalopesi, and H . tyranni.

Materials and methods Blood smears from tyrannids collected by collaborators in the

Neotropical and Nearctic regions and deposited in the International Reference Centre for Avian Haematozoa (IRCAH) were the basis of this study. The blood films were air dried, fixed in 100% methanol or ethanol, and stained with a variety of blood stains such as Wright's or Giemsa's. Blood films made or stained at the Centre were stained in Giemsa's stain at pH 7.2 and rinsed in slightly acidic water (pH 6.5). Morphological parameters (Bennett and Campbell 1972; Forrester et al. 1977) were obtained by drawing the appropriate cell with the aid of a camera lucida and determining the lengths and areas with a Zeiss

Macrogametocyte (Fig. 1, Table 1) Parasite large, completely filling host erythrocyte, surround-

ing erythrocyte nucleus which is not displaced; host erythrocyte hypertrophied in both length and width; parasite cytoplasm finely granular, staining deep blue with Giemsa's; parasite nucleus compact, broadly ovoid, median; pigment granules numerous and prominent.

-. Microgametocyte (Fig. 2 , Table 1 )

General configuration as in the macrogametocyte with the usual sexual differences (Garnham 1966); parasite nucleus stains poorly with Giemsa's and is hard to define.

Basis of description HAPANTOTYPE: Blood film No. 31 170 from Mionectes

olivaceous Lawrence, collected by Borrero, Rio Verde (1 120 m), Valle, Colombia, May 1972.

Comments Haemoproteus circumnuclearis is a typical haemoproteid

that surrounds the erythrocyte nucleus and completely occupies the host cell, causing hypertrophy. It is unique in that it represents the only described circumnuclear haemoproteid in a family of the Passeriformes. The remainder of the circum- nuclear haemoproteids occur in phylogenetically more primi- tive avian groups.

Haemoproteus souzalopesi n . sp.

TYPE HOST: FUSCOUS flycatcher, Cnemotriccus fuscatus (Wied.).

TYPE LOCALITY: Guaratuba, S5o Paulo State, Brazil. MOP-3 digital analyzer. A multivariate analysis of variance and Immature gametocyte subsequent univariate t-tests were performed. The measurements in the table or text are expressed as means followed (in parentheses) by the Youngest parasites seen initiate growth in a polar standard deviation. The number of specimens is indicated by N and the position, more lateral to the nuclear displacement ratio as the NDR.

All hapantotype and parahapantotype slides are deposited in the type collection of IRCAH .

Haemoproteus circumnuclearis n . sp. TYPE HOST: Olive-striped flycatcher, Mionectes olivaceous

Lawrence. TYPE LOCALITY: Rio Verde, Valle, Colombia.

Immature gametocyte Youngest forms seen initiate growth either lateral to the

erythrocyte nucleus or in a polar position.

Macrogametocyte (Figs. 3 , 4 ; Table 1 ) Parasite discoid, grossly displacing erythrocyte nucleus

laterally or to a pole, frequently rotating erythrocyte nucleus 90" to the normal axis; parasite cytoplasm finely granular, staining pale blue with Giemsa's; parasite nucleus compact, dense, round to ovoid, located from centre to periphery of parasite; pigment granules distinct, blackish brown, frequently aggre- gated in one or two clumps; host erythrocyte unchanged in length but grossly hypertrophied in width and area. Parasites enucleate 3-5% of host erythrocytes. Morphometric parameters of 10 enucleated erythrocytes and their parasites: erythrocytes

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FIGS. 1 and 2. Haemoproteus circumnuclearis. Fig. 1 . Two macrogarnetocytes. Fig. 2. Microgametocyte. FIGS. 3 and 4. Haemoproteus souzalopesi. Fig. 3 . Macro- and micro-gametocytes . Young macrogametocyte on left margin, mature macrogametocyte in upper right comer. Note lobate nuclei of microgametocytes. Fig. 4. Macrogametocytes. Note macrogametocyte in enucleated cell in upper left comer. FIGS. 5 and 6. Haemoproteus tyranni. Fig. 5 . Macro- and micro-gametocytes. Microgametocyte in slightly distorted erythrocyte. Fig. 6. Typical microgarnetocyte.

10.0 (0.9) pm in length (15% atrophy), 6.5 (0.3) pm in width identical with those in nucleated cells (Table 1) but erythrocyte (6% atrophy), 52.2 (6.9) pm2 in area (1 7% atrophy); parasites dimensions substantially smaller. 5.4 (0.7) pm in length, 4.9 (0.5) pm in width, 20.6 (4.2) pm2 in area; parasite nucleus 1.7 (0.2) pm in length, 1.5 (0.2) pm in Microgametocyte (Fig. 3; Table 1 ) width, 1.7 (0.4) pm2 in area, pigment granules average 13 (1.3) General configuration as for macrogametocyte with usual per parasite. Parasite dimensions in enucleated cells virtually sexual differences; parasite nucleus frequently highly lobate,

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CAN. J . ZOOL. VOL. 64, 1986

TABLE 1. Morphometric parameters of three species of haemoproteids

H . circumnuclearis H . souzalopesi H . tyranni

Unparasitized erythrocyte Erythrocyte

Length ( ~ m ) Width ( ~ m ) Area (Fm2)

Erythrocyte nucleus Length (Fm) Width ( ~ m ) Area (Fm2) % area of total

Erythrocyte parasitized by macrogametocyte

Erythrocyte Length ( ~ m ) Width ( ~ m ) Area (pm2) % hypertrophy or atrophy? Length Width Area

Erythrocyte nucleus Length ( ~ m ) Width ( ~ m ) Area (Fm2)

% area erythrocyte-parasite complex % hypertrophy or atrophy

Length Width Area

NDR Macrogametocyte

Length ( ~ m ) Width ( ~ m ) Area (Fm)

% erythrocyte-parasite complex Macrogametocyte nucleus

Length ( ~ m ) Width (km) Area (Fm) % area of parasite

No. of pigment granules

-6 no change

-4 1 .o

Erythrocyte parasitized by microgametocyte

Erythrocyte Length ( ~ m ) Width (km) Area (Fm)

% hypertrophy or atrophy Length Width Area

Erythrocyte nucleus Length ( ~ m ) Width (km) Area (Fm)

% area of erythrocyte-parasite complex % hypertrophy or atrophy

Length Width Area

NDR Microgametocyte

Length ( ~ m )

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BENNE'IT ET AL.

TABLE 1. (concluded)

H. circumnuclearis H. souzalopesi H. tyranni

Width (pm) (pm)

% area erythrocyte-parasite complex Microgametocyte nucleus

Length (pm) Width (pm) Area (pm) % area of parasite

No. of pigment granules

*Standard deviation.

staining bright pink with Giemsa's. Microgametocytes in Microgametocyte (Figs. 5 , 6; Table 1 ) enucleated erythrocytes virtually identical in all dimensions General configurations and dimensions as for the macro- with those in nucleated erythrocytes; enucleated erythrocyte gametocyte with the usual sexual differences. dimensions as for those containing macrogametocytes. Basis of description

Basis of description HAPANTOTYPE: Blood film No. 83024 from Cnemotriccus

fiscatus (Wied.) collected by Souza Lopes, Guaratuba (23'40' S; 45'55' W), Siio Paulo State, Brazil, 21 October 1969.

ADDITIONAL RECORDS: Empidonax euleri (Cabanis), Sao Paulo State, Brazil; Myarchis crinitus (L.), Maryland, U.S. A. ; Myiozetetes cayanensis (L. ) , Colombia.

Comments Haemoproteus souzalopesi is the second of the unique

discoid species seen in Neotropical birds. The other discoid species, H. ortalidum, occurs in the curassows (Cracidae) and is clearly separable from H. souzalopesi by its larger size (about 50% larger) and presence of the large, clear vacuole. In addition, H. ortalidum rarely enucleates the host erythrocyte and has an elongate sausage-shaped immature stage which is absent in H. souzalopesi.

The hapantotype blood film of H. souzalopesi represents an intense infection of 5- 10% erythrocyte involvement. Multiple infections of erythrocytes were common with as many as eight parasites seen in a single erythrocyte. Mature parasites were seen in double and triple infections but there was no evidence that parasites in multiple infections of four or more actually matured.

This parasite is named in honor of Dr. Oscar de Souza Lopes of the Instituto Oswaldo Cruz in recognition of his contribution to our knowledge of the haematozoa of Brazilian birds.

Haemoproteus tyranni n . sp. TYPE HOST: Eastern kingbird, Tyrannus tyrannus (L.). TYPE LOCALITY: Missaquash Marsh, New Brunswick,

Canada.

Immature gametocyte Smallest forms seen usually initiate growth lateral to the

erythrocyte nucleus; margins of parasite entire but extremities frequently ameboid.

Macrogametocyte (Fig. 5; Table 1) Parasite halteridial with slightly ameboid extremities, occupy-

ing more than 50% of the erythrocyte; cytoplasm coarsely granular; parasite nucleus round to broadly ovoid, dense, median or subterminal in location; erythrocyte nucleus usually atrophied and only slightly displaced laterally (but on occasion, to the periphery); pigment granules vary from prominent to barely discernible.

HAPANTOTYPE: Blood film No. 28613 from Tyrannus tyran- nus (L,) collected by Bennett, Missaquash Marsh, New Bruns- wick, Canada, July 3, 1972.

PARAHAPANTOTYPES: Blood film Nos. 38468 and 39289 from Empidonax trailii (Audubon) collected by Bennett, Jolicure, New Brunswick, Canada, June 1 1 and 13,1974; blood film No. 75772 from Tyrannus melancholicus Vieil., collected by Souza Lopes, Guaratuba, Siio Paulo State, Brazil, February 12, 197 1.

ADDITIONAL RECORDS: All additional records from the collec- tion of IRCAH: Capsiempsis flaveola (Licht .) , Panama; Empi- donax flaviventris (Baird & Baird), Newfoundland, Canada; Empidonax varius (Vieil.), Brazil; Myarchis crinitus (L .), Maryland, U. S .A. ; Phyllomyias fasciatus (Thunberg), Brazil; Platyrinchus mystaceus Vieil. , Brazil.

Comments Statistical analyses showed uninfected cell measurements

among different hosts to be similar. Differences observed between parasite measurements among different hosts were considered to be insufficient evidence for the presence of separate species. Rather, such differences presumably reflect variability due to a number of environmental factors. Haemo- proteus tyranni is a typical halteridial haemoproteid and is similar to others in the Passeriformes. It is here considered a distinct species on the assumption that it is host family specific; a specificity demonstrated experimentally for a number of other species of haemoproteids. The validity of this assumption awaits experimental confirmation.

Acknowledgement The financial support of the Natural Sciences and Engineer-

ing Research Council of Canada to the senior author made this study possible.

BENNETT, G. F., and A. G. CAMPBELL. 1972. Avian haemoproteidae. I. Description of Haemoproteus fallisi n. sp. and a review of the haernoproteids of the family Turdidae. Can. J. Zool. 50: 1269- 1275.

BENNETT, G. F., and A. G. CAMPBELL. 1972. Avian Haemo- proteidae. I. Description of Haemoproteus fallisi n. sp. and a review of the haemoproteids of the family Turdidae. Can. J. Zool. 50: 1269- 1275.

FORRESTER, D. J., E. C. GREINER, G. F. BENNETT, and M. K. KIGAYE. 1977. Avian Haemoproteidae. 7. A review of the haemo- proteids of the family Ciconiidae (storks) and descriptions of Haemoproteus brodkorbi sp. nov. and H. peircei sp. nov. Can. J. Zool. 55: 1268- 1274.

GARNHAM, P. C. C. 1966. Malaria parasites and other Haemosporidia. Blackwell Scientific Publications, Oxford.

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