Potential environmental and host gender influences on prevalence of Haemogregarina platessae (Adeleorina: Haemogregarinidae) and suspected Haemohormidium terraenovae (incertae sedis) in Brazilian flounder from the Patos Lagoon Estuary, Southern Brazil

Abstract

Abstract. Flounder, Paralichthys orbignyanus (Valenciennes), were captured in polluted and non-polluted sites within the Patos Lagoon Estuary, southern Brazil, over four seasons. Blood films showed a high prevalence of infection with a haemogregarine, or mixed parasitaemias of this and an organism resembling Haemohormidium terraenovae So, 1972. Haemogregarine gamont stages conformed to existing descriptions of Desseria platessae (Lebailly, 1904) Siddall, 1995 from flatfishes, but intraerythrocytic division of meronts was observed, leading to the recommendation for nomenclatural correction, placing the haemogregarine in the genus Haemogregarina (sensu lato) Danilewsky, 1885. Statistical analyses suggested that although sample sizes were small, infections with meront stages, immature and mature gamonts were all influenced by site, and possibly therefore, by pollution. Season also appeared to determine likelihood of infection with meronts and immature gamonts, but not mature gamonts, while adult fish gender apparently affected infection with immature and mature gamonts, but not meronts. The H. terraenovaelike organism exhibited unusual extracellular forms and did not match closely with the type description of H. terraenovae; precise identification was therefore difficult. Data analyses suggested that parasitism by this organism was influenced by site and fish gender, since females and males from non-polluted water were infected, but only females from the polluted site. Season was also important and significantly more adult fish of both sexes were infected with this parasite in the Brazilian summer and autumn, compared with winter and spring. Finally, these appeared to be the first observations of Haemogregarina platessae, and possibly H. terraenovae, from the southern hemisphere.

Developing an Apicomplexan DNA Barcoding System to Detect Blood Parasites of Small Coral Reef Fishes

“…The parasites described by Davies et al (2008) were also rounded or oval, measuring 3.3 x 2.9 µm, comparable in size to those described in this study. It would appear that this parasite has a cosmopolitan distribution, having been described by So (1972) from a number of fishes from Newfoundland, the author noting that Laird and Bullock (1969) likely also recorded this species from fishes from New Brunswick, with further reports of this species infecting fishes from the east of Canada and the USA (see Davies et al 2008). Davies et al (2008) also mentioned the resemblance in morphology and size of H. terraenovae to H. cotti as well as to Haemohormidium scombri Henry, 1910.…”

“…The Haemohormidium-like organism discovered in the Selar crumenophthalmus (Carangidae) from St Thomas, was comparable to that identified as perhaps Haemohormidium terraenovae So, 1972 by Davies et al (2008) from the blood of estuarine Brazilian flounder Paralichthys orbigynyanus (Paralichthyidae) from southern Brazil. Similarly, parasitaemias were very low and leucocytes were not affected.…”

“…It would appear that this parasite has a cosmopolitan distribution, having been described by So (1972) from a number of fishes from Newfoundland, the author noting that Laird and Bullock (1969) likely also recorded this species from fishes from New Brunswick, with further reports of this species infecting fishes from the east of Canada and the USA (see Davies et al 2008). Davies et al (2008) also mentioned the resemblance in morphology and size of H. terraenovae to H. cotti as well as to Haemohormidium scombri Henry, 1910. Khan et al (1980 suggested that H. terraenovae species could represent a composite or number of cryptic species (see Davies et al 2008).…”

Protozoan infections in farmed fish from Brazil: diagnosis and pathogenesis

“…this stage is not found (DAVIES et al, 2004). In Brazil, Haemogregarina was found parasitizing lungfish piramboia Lepidosiren paradoxa, mullet Mugil liza and sole Paralichthys orbignyanus (JEPPS, 1927;EIRAS et al, 1995;DAVIES et al, 2008), while Cyrilia lignieresi Laveran, 1906 was found in the blood of marbled swamp eel Synbranchus marmoratus (LAINSON 1981(LAINSON , 1992DINIZ et al 2002).…”

“…They are commonly found in both erythrocytes and leukocytes of marine fishes (DAVIES, 1995), except for Cyrilia spp., which parasitize only the erythrocytes of freshwater fish. According to Davies et al (2008), although most fish haemogregarine life cycles are unknown, fishes are likely to act as intermediate hosts, while leeches or gnathiid isopods are probably the definitive ones.…”