Mexico is a megadiverse country, however its tardigrade fauna is poorly known and to date 44 species have been reported from this region. In the present paper, an update of the reported Mexican tardigrades is presented, increasing the number of recorded tardigrades to 55 species (11 new records). Moreover, we describe Milnesium cassandrae sp. nov. from State of Nuevo León in northern Mexico. The new species is most similar to Mil. krzysztofi Kaczmarek & Michalczyk, 2007 and Mil. beasleyi Kaczmarek, Jakubowska & Michalczyk, 2012, but it differs from them mainly by details of the dorsal sculpture and some morphometric characters. We also discuss the taxonomic value of a recently described feature, ‘pseudoplates’, for differentiating the taxa within the genus Milnesium Doyère, 1840. [Zoobank URL: urn:lsid:zoobank.org:act:0684AE18-0510-4F7B-B75D-AE5177FBF2A2]

Milnesium, with its relatively short and wide buccal tube, is considered carnivorous. Species in this genus exhibit differences in buccal tube length, standard buccal tube width, and the buccal tube length/width ratio. To determine whether buccal tube size is correlated with the type of prey,~4000 specimens of various Milnesium species were examined. Among those with identifiable gut contents,~97% contained tardigrades, rotifers, or both, whereas only~3% contained nematodes or amoebas. In total, 189 females with guts containing only tardigrades, only rotifers, or both were analysed with general linear model multivariate analysis. Milnesium specimens containing only tardigrade remnants were larger and had longer and wider buccal tubes than those containing only rotifers. Those with only tardigrades in the gut also had a significantly lower buccal tube length to width ratio than those with only rotifers in the gut. Specimens with a mixed diet (rotifers and tardigrades) had intermediate values of buccal tube width and length, and these differed significantly from individuals containing rotifers or tardigrades only. Variation in buccal tube dimensions was linked with interspecific and age (size)related factors, and differences in buccal tube dimensions associated with gut content remained significant, even when the analysis was controlled for the interspecific variation. No evidence of cannibalism was observed.

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In this paper we provide the first record of the eutardigrade Dactylobiotus parthenogeneticus Bertolani, 1982 from Mexico (North America). Our report increases the range of this species and the number of tardigrade species known from Mexico to 43 taxa.

One of the key drivers of pollinator declines is land cover change. We documented for the first time the impacts of over three decades of land cover change in Mexico on the plant resources of an endangered migratory pollinator, the Mexican long-nosed bat, Leptonycteris nivalis. This species is considered endangered under national and international criteria due to population declines over 50% in the past 10 years. Pregnant females of this bat species migrate every year following the blooms of Agave spp. from central Mexico to the southern United States; moving pollen over its 1,200 km long migratory corridor and pollinating distant populations of Agave spp. Increases in human populations density and agricultural expansion may be reducing agave habitat over time. The objective of our study is to understand the land cover change trends in the northern range of the bat and identify potential fragmentation patterns in the region. We analyzed changes that occurred in three vegetation types where agaves are found in five time periods 1985, 1993, 2002, 2007 and 2011. The area of the three vegetation types selected was reduced by using only the overlap with potential agave habitat created with ecological niche modeling algorithms to obtain the available agave habitat. We then calculated fragmentation metrics for each period. We found a significant portion of habitat lost mainly due to expansion in agriculture. The total number of patches increased after 1985. Only 9% of the available agave habitat in 2011 is inside the limits of protected areas. We recommend restoring agave populations in depleted areas to help prevent soil erosion and provide multiple socio-economic benefits for the region in the short term, and, in the long-term maintaining foraging resources for nectar-feeding bats.