Assessing the genetic diversity of the metacercariae of Posthodiplostomum minimum (Trematoda: Diplostomidae) in Middle American freshwater fishes: one species or more?
Por:
Perez-Ponce de Leon, Gerardo, Sereno-Uribe, Ana L., Pinacho-Pinacho, Carlos D., Garcia-Varela, Martin
Publicada:
1 feb 2022
Resumen:
Trematode taxonomy is mainly based on the morphological traits of
adults. The identification of metacercariae is challenging because such
traits are not developed in larval forms, and they even may show some
level of morphological variability. Studies testing the potential
correspondence between morphological differences and genetic variation
of parasites are still lacking. The metacercariae of Posthodiplostomum
minimum are probably the diplostomids more widely distributed in North
and Middle American freshwater fish, and their intraspecific
morphological variability has been attributed to the effect exerted by
the host. Here, we tested the hypothesis whether they represent a single
species, or a species complex by assessing the genetic divergence and
phylogenetic relationships of metacercariae sampled from several host
species in a wide geographical range across Middle America. The internal
transcribed spacers (ITS1-5.8S-ITS2), and the mitochondrial COI gene
were sequenced for 124 and 55 metacercariae, respectively. Phylogenetic
analysis inferred from ITS sequences uncovered six well-supported
monophyletic lineages. The six lineages show no correspondence to any
Posthodiplostomum species for which sequences are available thus far in
GenBank. Lineages exhibit some degree of host specificity; Lineages I,
II, IV and V are primarily parasites of cyprinodontiforms of the
families Poeciliidae, Goodeidae, Profundulidae and Fundulidae. In
poeciliids there are at least four candidate species of
Posthodiplostomum, some of them occurring in sympatry; instead, Lineages
II and VI are exclusively parasites of cichlids. This study contributes
to our understanding of the diversity of larval forms of diplostomids
and provides an opportunity to further study their life cycles.
Filiaciones:
Perez-Ponce de Leon, Gerardo:
Univ Nacl Autonoma Mexico, Inst Biol, Dept Zool, Ap Postal 70-153, Ciudad De Mexico 04510, Mexico
Univ Nacl Autonoma Mexico, Escuela Nacl Estudios Super, Unidad Merida, Km 4-5 Carretera Merida Tetiz, Municipio De Ucu 97357, Yucatan, Mexico
Sereno-Uribe, Ana L.:
Univ Nacl Autonoma Mexico, Inst Biol, Dept Zool, Ap Postal 70-153, Ciudad De Mexico 04510, Mexico
Pinacho-Pinacho, Carlos D.:
Inst Ecol AC, Red Estudios Mol Avanzados, Catedras CONACyT, Kilometro 2-5 Ant Carretera Coatepec, Xalapa 91070, Veracruz, Mexico
Garcia-Varela, Martin:
Univ Nacl Autonoma Mexico, Inst Biol, Dept Zool, Ap Postal 70-153, Ciudad De Mexico 04510, Mexico
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