A paradise for parasites? Seven new haemogregarine species infecting lizards from the Canary Islands

Abstract

Oceanic islands are hotspots of biodiversity due to their high levels of endemism, with the Canary Islands being a notable example. A previous molecular study on the biogeography and host associations of haemogregarines (Apicomplexa: Adeleorina) infecting lizards from this archipelago detected seven parasite haplogroups. These haplogroups exhibited high host-specificity and geographical structure, suggesting that they might correspond to distinct biological identities. In this study, along with sequencing a longer fragment of the 18S rRNA, we further explore the distinctiveness of these parasites by analysing their morphology, effects on host erythrocytes and parasitaemia levels. These lines of evidence together with their genetics, host associations, frequency of occurrence and geographical distribution support them as different biological entities. As such, we describe seven new species: Karyolysus canariensis sp. nov., Karyolysus galloti sp. nov., Karyolysus stehlini sp. nov., Karyolysus gomerensis sp. nov., Karyolysus atlanticus sp. nov., Karyolysus tinerfensis sp. nov. and Karyolysus makariogeckonis sp. nov. These new taxa are further examples of endemic diversity in the Canarian archipelago. They also contribute to clarify the taxonomy within the Apicomplexa, a phylum estimated to have one of the lowest percentages of described species.

Diversity ofKaryolysusandSchellackiafrom the Iberian lizardLacerta schreiberiwith sequence data from engorged ticks

“…The effect on host cells is not always uniform among species. For example, various levels of erythrocyte distortion were observed between seven Canarian species of Karyolysus (Tomé et al ., 2019). The recently redescribed K. paradoxa (Cook et al ., 2016) shows specific effects on host cells such as the shrinkage of erythrocytes and vacuolization of its nucleus, different from the effects of other species of Karyolysus.…”

“…They have been considered to be parasites of Palearctic lizards, mainly reported from European countries such as Poland, Hungary, Romania, Slovakia and Spain (Álvarez-Calvo, 1975; Haklová-Kočíková et al ., 2014), but also from Scandinavia (Svahn, 1974, 1975) and Russia (Beyer and Sidorenko, 1984). Newly, seven species have been found in the Canary Islands (Tomé et al ., 2019). Nevertheless, reports from India (de Mello and de Meyrelles, 1937), Kenya (Mutinga and Dipeolu, 1989) and recently also from South Africa (Cook et al ., 2016) are changing this view.…”

“…The prevailing vertebrate hosts are lacertid lizards of the genera Gallotia , Lacerta , Podarcis and Zootoca . However, records of Karyolysus from varanid, scincid and geckonid lizards (Mutinga and Dipeolu, 1989; Cook et al ., 2016; Tomé et al ., 2019) have broadened its known host range. Furthermore, based on molecular surveys, there are many probably incorrectly assigned Hepatozoon isolates from lizards and snakes, which might resemble species of Karyolysus (Maia et al ., 2011; Tomé et al ., 2012, 2013; Karadjian et al ., 2015).…”

Where are we in the host-parasite relationships of native land vertebrates in Macaronesia?

“…Las hemogregarinas de reptiles tienen un ciclo de vida con dos hospedadores: un vertebrado (reptil) y un artrópodo hematófago (ácaro o garrapata); y en donde la transmisión tiene lugar por depredación. En las islas Canarias, estos invertebrados son extremadamente abundantes habiéndose descrito algunas especies endémica (Fain y Bannert 2000, circunstancia que ha propiciado una significativa diferenciación morfológica y genética de sus hemogregarinas parásitas (Tomé et al 2019). Estos resultados parecen desalinearse con las predicciones relativas a la menor riqueza de parásitos en islas en relación con el continente.…”

“…Uno de los resultados más llamativos es la marcada estructura geográfica encontrada en estos parásitos, que simultáneamente concuerda con la distribución de sus hospedadores vertebrados (Tomé et al 2018(Tomé et al , 2019; esta circunstancia refleja, en general, la historia evolutiva de la colonización de los reptiles de Canarias. Un resultado interesante es que no parece existir una presencia equitativa de parásitos en los tres grupos de reptiles canarios.…”