The mouse-eared bats or myotises are a diverse and widespread genus (Myotis) of bats within the family Vespertilionidae. The noun "myotis" itself is a New Latin construction, from the Greek "muós (meaning "mouse") and "oûs" (meaning ear), literally translating to "mouse-eared".[1]
Myotis has historically been included in the subfamily Vespertilioninae, but was classified in its own subfamily, Myotinae, by Nancy Simmons in 1998. In her 2005 classification in Mammal Species of the World, Simmons listed the genera Cistugo and Lasionycteris in the Myotinae in addition to Myotis itself.[2] However, molecular data indicate that Cistugo is distantly related to all other Vespertilionidae, so it was reclassified into its own family, the Cistugidae,[3] and that Lasionycteris belongs in the Vespertilioninae.[4] The genus Submyotodon has since been added to the subfamily, making it and Myotis its only members.[5]
Their ears are normally longer than they are wide, with a long and lance-shaped tragus, hence their English and zoological names. The species within this genus vary in size from very large to very small for vesper bats, with a single pair of mammary glands.
Mouse-eared bats are generally insectivores. M. vivesi, and several members of the trawling bat ecomorph Leuconoe, have relatively large feet with long toes, and take small fish from the water surface (they also take insects).[6]
Myotis species are remarkably long-lived for their size; in 2018, researchers revealed that a longitudinal study appears to indicate that Myotis telomeres do not shrink with age, and that telomerase does not appear to be present in the Myotis metabolism. 13 species of Myotis bats live longer than 20 years and 4 species live longer than 30 years.[7][8]
Traditionally, Myotis has been divided into three large subgenera—Leuconoe, Myotis, and Selysius. However, molecular data indicate that these subgenera are not natural groups, but instead unnatural assemblages of convergently similar species.[10] Instead, Myotis species largely fall in two main clades, one containing Old World and the other New World species.[9] However, the Asian species Myotis latirostris falls outside the clade formed by these main groups, and may represent a separate genus,[11] and the Eurasian Myotis brandtii is related to New World species.[12]