Nicaragua is a biodiverse country, but documented herpetological specimens are underrepresented when compared to other neighboring countries. In 2018 we conducted a collaborative expedition between the University of Michigan Museum of Zoology and Nicaraguan biologists. We visited three collection sites in the Pacific lowlands, Caribbean lowlands, and the Central Highlands, representing three major biogeographic regions. We collected specimens of 100 species from a total of 106 encountered. We provide accession numbers, morphological, genetic, and ecological information for these specimens. We recorded 23 new departmental and the first country record of Metlapilcoatlus indomitus (Smith & Ferrari-Castro, 2008), helping filling gaps in the known distribution of the species within Nicaragua and the Central American region. When available, we provide species range maps and comparative genetic tree including conspecific reference sequences from the region.

In the field, we collected a set of morphological, ecological, and behavioral metadata associated with each specimen. Specifically, we collected basic morphometric data (snout-vent length, mass, and tail length where applicable), GPS coordinates of the capture location (WGS84), and standardized ecological and behavioral observations made at the specimens’ point of capture when possible. We include all additional morphometrical data as supplemental material. Our ecological data include macrohabitat type (such as upland forest or riparian habitat), the substrate on which the animal was resting at the time of encounter (such as ground, leaf, trunk, or branch), perch height and diameter, and a description of the behavior of the animal at the time of encounter. We included this information in the remarks section of the species accounts.