Morphologic and Morphometric Analysis of Hepatozoon spp. (Apicomplexa, Hepatozoidae) of Snakes
Tatiana Cristina Moço, Lucia Helena O'Dwyer/+, Fabiana Custódio Vilela*, Thomaz Henrique Barrella*, Reinaldo José da Silva
Departamento de Parasitologia, Instituto de Biociências, Unesp, Distrito de Rubião Júnior s/nº, 18618-000 Botucatu, SP, Brasil *Centro de Estudos de Venenos e Animais Peçonhentos, Unesp, SP, Brasil
An Open Access article from Mem. Inst. Oswaldo Cruz vol.97 no.8 Rio de Janeiro Dec. 2002 Vol. 97(8): 1169-1176, December 200.
are the most abundant hemoparasites of snakes. Its identification has
been based mainly on the morphologic characterization of the gamonts in
the peripheral blood of the vertebrate host and also of the cysts found
in the internal organs of the vertebrate and invertebrate hosts. Using
a computerized image analysis system, we studied five species of Hepatozoon from
recently captured snakes in Botucatu, State of São Paulo, Brazil, to
evaluate the importance of the morphology and morphometry of the
gamonts for the characterization of Hepatozoon species and to analyze the morphologic changes induced in the erythrocytes by the parasite. The studied species were H. terzii of Boa constrictor amarali, Hepatozoon sp. of Crotalus durissusterrificus, H. philodryasi of Philodryas patagoniensis, and H. migonei and H. cyclagrasi of Hydrodynastes gigas. We observed three different groups, one of them including the species H. terzii, H. philodryasi and Hepatozoon sp. of C. durissus terrificus; and the other two consisting of H. migonei and H. cyclagrasi. Degree of alterations in the erythrocytes was variable and it may be useful for characterization of Hepatozoon species.
Key words: Hepatozoon - parasites - snakes - morphometry - morphology - erythrocytes
Hepatozoon species are the most abundant hemoparasites of snakes (Wozniak et al. 1994). Many Hepatozoon species have been described among Brazilian snakes: H. juxtanuclearis (Carini 1947, Pessoa 1967), H. fusifex (Ball et al. 1969) and H. terzii (Sambon 1909) parasites of Boa constrictor, H. romani and H. capsulata (Phisalix 1931) parasites of Crotalus durissus terrificus, H. philodryasi (Carini 1910) parasite of Philodryas patagoniensis, H. migonei (Arantes 1934, Schouten 1934, Pessoa et al. 1970) and H. cyclagrasi (Pessoa et al. 1970) parasites of Hydrodynastes gigas.
Identification of Hepatozoon species
has been based mainly on the morphologic characterization of the
gamonts in the peripheral blood of the vertebrate host and also of the
cysts found in the internal organs of the vertebrate and invertebrate
hosts. However, these stages are very similar for the different species
of Hepatozoon, and so the identification based only on these
characteristics may be incorrect (Pessoa & De Biasi 1973, Pessoa et
The main reports of Brazilian snake Hepatozoon
give information on the morphology of the gamonts (shape, stain, and
capsule presence) and also provide morphometric data usually consisting
of the description of the length and width of the gamonts and cysts. In
recent works, using computerized image analysis systems, measurements
of the parasite and nucleus areas have been also reported (Silva et al.
1999). Morphometric analysis allows a more detailed evaluation of
cellular morphology, including linear and area measurements.
Morphological descriptions of most Hepatozoon
species of Brazilian snakes are of fundamental importance to contribute
to the knowledge of this group of parasites. A complete morphological
description of a Hepatozoon species should include
morphological and morphometric features of all stages of the parasite,
including the sporogonic stages in the arthropod vector.
The objective of the present investigation was to study species of Hepatozoon
in recently captured snakes from Botucatu, State São Paulo, Brazil, to
evaluate the importance of morphology and morphometry for the
characterization of the species, and to analyze the morphologic
alterations induced in the erythrocytes by the presence of the