Geometric morphometrics of the mite Laelaps mazzai associated with diferent species of the sigmodontine rodent Calomys in Argentina

ESPINOZA-CARNIGLIA, MARIO; ULYSES F.J. PARDIÑAS; LARESCHI MARCELA

Congreso; II Virtual Meeting of Systematics, Biogeography, and Evolution; 2021

Calomys (Rodentia, Cricetidae) is one of the most widespread genera of Neotropical rodent fauna. Pelage coloration, length, and appearance vary greatly among species and sometimes among populations of the same species. In Argentina, they are represented by 7 species, some of them well distributed and with zoonotic importance. Previous records associate Calomys laucha, Calomys musculinus and Calomys callosus with Laelaps mazzai (Mesostigmata, Laelapidae) in Argentina, a mite with a hypertrichous dorsal shield. Since its description, Laelaps mazzai has been poorly studied. Although, other laelapids have been proposed as specific, it hasn?t been studied if there are specific relationships with its hosts for Laelaps mazzai. Here we explore the morphologic variation of dorsal and ventral shields of females of Laelaps mazzai in Calomys rodents from Argentina to evaluate if they are associated with their different host species. For this we take photographies of 48 Laelaps mazzai from Calomys callosus (n = 21), Calomys callidus (n = 12), Calomys laucha (n = 8), Calomys venustus (n = 5) and Calomys musculinus (n = 2). We positioned 64 landmarks in setae insertions and pores from dorsal shield (DS) and 16 landmarks in ventral shields [sternal (SS), metaesternal (MS) and genitoventral (GS)] with the tpsDig2 software. Shape variations were analyzed with a Canonical Variate Analysis in MorphoJ. Differences were showed with Procrustes distances and p-values are calculated with 100000 permutations. Results show that there are five different morphotypes of Laelaps mazzai that belong to their respective host species. These morphotypes are also different on the sclerotization level of the shields. Here we found different morphotypes of Laelaps mazzai related to their host species, these differences may be related with the species identity of each host, but further studies are needed to clarify the morphological variation of Laelaps mazzai.