PROTOZOA: EUCOCCIDIIDA & MICROSPORIDIA

The taxonomic ranks (family, genus, and subgenus) that were created for some of the species are not listed in table 1 and are as follows: the haemosporidian genus Saurocytozoon Lainson & Shaw, 1969² ; the haemosporidian family Garnidae Lainson, Landau & Shaw, 1971³ containing the genera Garnia Lainson, Landau & Shaw, 1971, Fallisia Lainson, Landau & Shaw, 1974⁴, and Progarnia Lainson, 1995⁵; two hemogregarine genera Cyrilia Lainson, 1981⁶ and Hemolivia Petit, Landau, Baccam & Lainson, 1990⁷; and the microsporidian genus Alloglugea Paperna & Lainson, 1995⁸. A simple question is why were they found? All are from cold-blooded vertebrates and the majority is from lizards. While searching for lizard Leishmania that to this date have never been found in the Americas, a wealth of parasites was discovered in different blood cells, opening new research areas. However, besides this, it was obvious that an enormous number of parasites was waiting to be discovered. Thus, any available animal was examined for parasites, irrespective of it being a potential reservoir of a human disease.

Their discoveries stimulated others to look for them around the world. Garnia is only known in the Western Hemisphere; Fallisia species have been recorded in the Americas, South East Asia, and Australasia; and Saurocytozoon occurs in both North and South America and in Asia⁹. Molecular methods are now showing possible evolutionary pathways that reflect the above distributions. The 60 Eimeridae species listed in table 1 were found in either warm or cold blooded vertebrates. A recent paper¹⁰ showed that species of Cyclospora, Eimeria, and Isospora from warm blooded vertebrates form a well-supported clade, but organisms identified as Eimeria or Isospora species from cold-blooded vertebrates and marsupials do not fall within this group, suggesting that these are polyphyletic genera. For example, based on 18S rRNA sequences¹⁰, two Eimeria species, one from a snake and the other from an anuran, were phylogenetically closer to European Schellackia species within the family Schellackiidae. These observations clearly indicate that future revisions will be required to resolve the polyphyletic genera.

Six species of Sarcocystis were described based on distinctive cyst wall morphology. Except for one, their definitive hosts are unknown. The sexual cycle of Sarcocystis ameivamastigodryasi Lainson & Paperna, 2000¹¹ of the teiid lizard, Ameiva ameiva occurs in the intestine of the colubrid snake, Mastigodryas bifossatus. The oocysts are like those of Isospora species having two sporocysts that contain four sporozoites. In the case of the teiid parasite, the oocyst wall ruptures inside the snake's intestine so mature sporocysts are liberated in the faeces. The cystic stage normally occurs in herbivores and the sexual stage in carnivores ranging from canids, corvid birds to snakes. It is possible that some Isospora species could in fact be Sarcocystis species.

PROTOZOA: KINETOPLASTIDA

Given the medical importance of Leishmania species, it is not surprising that the most well-known taxa and taxonomic rank, established in Belém, Pará State, under Wellcome Trust funding, belong to this genus. The creation of the subgenus Leishmania (Viannia) Lainson & Shaw, 1987¹² was a fundamental step forward in understanding the disease known as leishmaniasis and its phylogeny. Parasites belonging to this subgenus are only found in the Americas, while those of the subgenus Leishmania (Leishmania) are found in the Old World and the Americas. Three previously named organisms, L. braziliensis, L. guyanensis, and L. peruviana were assigned to this subgenus and eight other species were described (Table 1). All but two of these belong to the subgenus L. (Viannia). One of these, L. (L.) amazonensis Lainson & Shaw, 1972¹³, grows profusely in culture and readily infects a range of laboratory animals, producing in hamsters a pathology like diffuse cutaneous leishmaniasis. Because of these attributes this parasite is used extensively in immunological and chemotherapeutic studies. Molecular methods¹⁴ have shown that the subgenus L. (Viannia) separated from the basal stock some 80 MYA while the subgenus L. (Leishmania) separation was later being around 50 MYA. There are distinct differences between the immunological response and pathology of the two subgenera in man. Somewhere along the evolutionary line, the subgenus L. (Leishmania) seems to have opted to depress the cell mediated response, while the subgenus L. (Viannia) opted to stimulate it. Perhaps this was due to the very different mammalian hosts in which the two subgenera evolved, one possible being rodents and the other Xenarthra. Today we see this reflected in the extreme immunological differences between diffuse cutaneous leishmaniasis caused by L. (L.) amazonensis and mucocutaneous by L. (V.) braziliensis¹⁵.

Leishmania hertigi deanei Lainson & Shaw 1977¹⁶, later raised to specific status by Lainson and Shaw¹² in 1987, is very different from all other Leishmania. The amastigotes are very large and do not appear to be intracellular. Latterly studies have shown that it is phylogenetically outside the genus Leishmania being closer to Endotrypanum. This led to the creation of the genus Porcisia Shaw, Camargo & Teixeira 2016¹⁷ to accommodate it and the Panamanian porcupine parasite, P. hertigi.

Great advances in our understanding of the taxonomy of Trypanosoma (Schizotrypanum) cruzi were made by Miles et al.¹⁸ while working at the Instituto Evandro Chagas that confirmed three genetically distinct lineages that were denoted as Type I, II & III. In the opinion of the author these represent distinct species but have never been named so they do not appear in table 1. Subsequently these lineages have been shown to be distinct by with different molecular markers.

INSECTA: DIPTERA: PSYCHODIDAE: PHLEBOTOMINAE

Unravelling the epidemiologies of the different Leishmania species inevitable led to the discovery of new phlebotomine species. It also showed how the epidemiological importance of different groups varies in different biomes. The discovery of Psychodopygus wellcomei Fraiha, Shaw & Lainson 1971¹⁹ was the first indication of the vectorial importance of this genus for L. (Viannia) species in Amazonia. Six Psychodopygus species are associated with L. (V.) braziliensis and five with L. (V.) naiffi²⁰. It is the predominant genus in south of the Amazon River extending to virgin Atlantic rain forest. In north of the river, L. (V.) guyanensis, transmitted by N. umbratilis, is the dominant leishmania in man. The number of Nyssomyia sand flies is significantly greater in this biome, but there is no significant difference in the variety of species of Nyssomyia and Psychodopygus²¹.

Continuous environmental variations related to global warming and man's activities modulate the sand fly fauna. Understanding and documenting this is the challenge.