It is important that species descriptions be accurate. This is especially true with threatened and endangered species, where the scientific literature provides context for species identification and management decisions. In 1953, Bragg documented the advertisement calls of both Southern Crawfish Frogs (Lithobates a. areolatus) and Northern Crawfish Frogs (L. a. circulosus) and concluded L. a. areolatus have lower frequency calls. One of us (M.J.L.) has long felt this observation was incorrect, because adult L. a. areolatus are smaller than L. a. circulosus, and anurans with smaller body sizes tend to produce higher, not lower, frequency calls. Bragg's observations are not only the sole comparative assessment of advertisement call characteristics of L. areolatus in the primary literature, but also represent the only assessment of the advertisement calls of any of the four species comprising the subgenus Nenirana, which consists of threatened and endangered Gopher Frogs (L. capito and L. sevosus) and Pickerel Frogs (L. palustris). Given this dearth of information, the reliability of this information, and the conservation concerns surrounding this group, we felt it was necessary to reassess the advertisement calls of Crawfish Frogs and give them context by describing the calls of the Nenirana species L. capito and L. palustris. Our data revise Bragg's conclusions, but just as importantly, we show that the call characteristics of L. capito and L. palustris are similar by having long calls with long interpulse intervals, while both subspecies of L. areolatus have shorter calls with less interpulse separation. These results do not align with morphological and phylogenetic clustering within the Nenirana, but are consistent with call character displacement within this group. Additional data will be necessary to test this inference.

Understanding how environmental factors influence various aspects of freshwater turtle health remains an important yet understudied topic within the context of individual–environment interactions. This is particularly true of host-associated bacterial microbiota, which are being increasingly recognized as a significant and understudied topic in the context of individual turtle health. While this area of work has expanded in certain areas, research efforts remain limited with regard to host–microbiota interactions in the context of habitat contaminants. Specifically, the commonly used herbicide, glyphosate, is of interest due to its massive worldwide use and known effects on various organisms. Effects of captivity on host-associated microbial community structure also remain largely unknown in various non-model organisms. To address these unknown effects of Roundup^® and captivity on host-associated microbiomes, we examined the effects of low-level Roundup^® exposure and captivity on the cloacal microbiota of the False Map Turtle, Graptemys pseudogeographica. We determined the effect of glyphosate by taking cloacal swabs pre- (0 h) and post-exposure (72 h) and examined microbial community beta- and alpha-diversity through 16S rRNA gene high-throughput sequencing. The results of this study indicate that low-level, short-term glyphosate exposure does not significantly alter the microbiota structure of G. pseudogeographica. However, there was a significant decrease in microbial community beta-diversity over time, confirming a trend that has been observed to a limited extent in other non-model organisms when put in laboratory conditions. These results are useful in understanding the baseline cloaca microbial community structure of G. pseudogeographica, as well as the implications and limitations of laboratory-based microbiota studies. Furthermore, this work suggests that low-level and short-term glyphosate exposure does not have a significant effect on the cloacal microbial community structure in wild-caught G. pseudogeographica.

Knowledge of how patterns in fish assemblages are spatially structured is important for guiding management and conservation actions. However, most studies have taken place in the eastern and midwestern U.S., resulting in a poor understanding of factors influencing western stream fishes. The objectives of this study were to evaluate habitat and species associations of fishes in Deep Creek, a small tributary of the Kootenai River in Idaho. Fishes and habitat were sampled from 58 reaches in Deep Creek. In total, 7,129 individual fishes representing 18 species were sampled. Patterns in species richness were largely a function of channel gradient and associated habitat characteristics. Species richness decreased with increased channel gradient. Species-specific habitat relationships for native and nonnative fishes in Deep Creek provided specific insights into the ecology of each species. Predicted probability of occurrence and relative abundance varied by species and were related to a broad suite of environmental characteristics. This study provides insight on patterns of fish assemblage structure, as well as important information on the ecology of native and nonnative fishes in a western stream system.

Long-term demographic data are important for conserving populations of threatened and endangered species. Collecting data specific to the population of interest can improve conservation success by allowing managers to make informed decisions, evaluate the efficacy of habitat management, and assess extinction risk. Population viability analysis (PVA), a tool commonly used to estimate extinction risk in threatened populations, is most informative when precise, population-specific data are available. We used mark-recapture data spanning ten years (2008–2017) to estimate annual adult survival rates in a population of threatened Eastern Massasauga rattlesnakes (Sistrurus catenatus) in Barry County, Michigan. Using these survival estimates and ten additional parameter values obtained from our site and a nearby population, we modeled population viability over the next 100 years. We performed sensitivity analysis using Latin hypercube sampling, followed by logistic regression to assess the relative influence of model parameters on extinction risk. We estimated annual apparent survival rates of 0.79 (95% CI = 0.69–0.87) for adult males and 0.78 (95% CI = 0.69–0.85) for adult females, which are higher than expected given the population's locality. Results of our sensitivity analysis suggest that actions promoting high survival of adult females should be a management priority, followed by activities that facilitate high reproductive output and neonate survival. We recommend focusing future research and monitoring efforts on these parameters.

A new species of Spatuloricaria is described from the Orinoco River basin, Colombia. The new species can be distinguished from its congeners by the following characters: a broad, dark brown stripe on the first pre-dorsal plate, which occupies the entire plate, reaching the preopercle, and sometimes reaching the second pre-dorsal plate; the possession of a small group of plates posterior to the urogenital pore; the abdominal surface with scattered, very small plates leaving naked areas; the possession of five transverse dark brown bands on the dorsal region; and four to five premaxillary teeth. The new species is the first valid species of Spatuloricaria distributed in the Orinoco River basin. Ecological notes of the species and comments regarding the taxonomy and phylogenetic relationships of the genus are offered.

An undescribed species of the frogfish genus Histiophryne, of the teleost order Lophiiformes, family Antennariidae, is described on the basis of 60 specimens collected from shallow inshore waters of Western and South Australia. Previously confused with its morphologically similar congener H. cryptacanthus, it differs from the latter and from all other members of the genus in having the following combination of features: illicium tiny but easily discernible without aid of a microscope; esca present, a small tuft of filaments, easily distinguished from illicium; skin covered with tiny dermal spinules, especially on head, cutaneous filaments and appendages absent; dorsal-fin rays 15–16; pectoral-fin rays 9 (rarely 8); vertebrae 22–23; head, body, and fins typically off white, sometimes peppered with numerous small, close-set ocelli. Genetic divergence from its congeners in the nuclear recombination activation gene-2 (RAG2) and cytochrome oxidase-I (COI) genes is at least 8.9%. The new species is diagnosed, described, and compared with its congeners. A revised key to the species of the genus is also provided.

Pareiorhaphis mucurina, new species, is described from the Preto River, a headwater tributary of the Mucuri River basin, Minas Gerais State, eastern Brazil. This description represents the first record of Pareiorhaphis in the Mucuri River basin, the intervening drainage between the Doce and the Jequitinhonha rivers, two large coastal drainages in eastern Brazil that are inhabited by six species of Pareiorhaphis. Pareiorhaphis mucurina, new species, is promptly diagnosed from all congeners by having a distinct, narrow area in the lower lip along and just posterior to each emergent tooth series of the dentary completely devoid of papillae and the lateral margin of the lower lip with a distinctly enlarged flap of skin, forming a continuous connection with most of the maxillary barbel. In addition, the new species can be further distinguished from all congeners by having the upper lip with distinctly shaped papillae, which are coalesced to form three or four transverse series of elongate skin folds. The well-developed dorsal-fin spinelet, the smaller orbital diameter, and features related to morphology of the fleshy lobes on the lateral portion of head of adult males, also distinguish the new species from most congeners.

The Gulf of Mexico Scientific and Environmental ROV Partnership using Existing iNdustrial Technology (Gulf SERPENT) Project utilizes industrial work-class ROVs based at oceanic oil and gas facilities for scientific research and exploration. During Gulf SERPENT operations, an ROV documented the first in situ observations of Gigantura chuni at a depth of approximately 900 m in the northern Gulf of Mexico. The fish were identified to genus by the length of the caudal fin ventral lobe relative to standard length, reflectance from crystalline guanine, and relative mouth size to the head length. The width-length ratios suggest G. chuni as the species (approximately 1:5 for adult G. chuni vs. 1:10 for adult G. indica). The videos provided the second known in situ observation of giganturids and the first of G. chuni. The first video clearly shows two individuals in close proximity, with both oriented vertically in the water column; a second video clip shows a single individual at a slightly shallower depth, and also oriented vertically in the water column. An odds ratio comparison for collections of G. chuni and G. indica from the DEEPEND program to fitted theoretical distributions was used to preliminarily analyze the probability of encountering various numbers of individuals in a single-sample effort. Groups of two individuals, and in particular even number groupings, were encountered during the DEEPEND program sampling more often than would be expected based on theoretical distributions for both G. chuni and G. indica suggesting pair-bonding may be a likely reproductive strategy complementing synchronous hermaphroditism in giganturids.

Mark-recapture methods used in population demography studies involve marking of animals, such as tagging, notching, and tattooing. These techniques are invasive and potentially harmful to the animals. Photo-identification using natural animal markings is less invasive and has become more widely used for a range of taxa including invertebrates, fishes, reptiles, amphibians, and mammals. During 2016 and 2017, we studied the demographics of the Rio Grande Cooter (Pseudemys gorzugi) using traditional mark-recapture techniques (i.e., shell notching and toe clipping). However, P. gorzugi displays plastral marks that could potentially be used for individual recognition. Because the photo-identification process ‘by-eye' is time consuming, we tested the efficiency of three pieces of software, I³S Pattern , Wild.ID, and APHIS, for individual identification of P. gorzugi using plastron pattern. Matching results of each program were generated into ranks with the 1^st rank being the most likely match. Within the top 20 ranked images, Wild.ID yielded the highest number of correct matches (83.87%), followed by APHIS (ITM; 69.35%), APHIS (SPM; 67.74%), and I³S Pattern (61.29%). We found the quality of photos significantly contributed to the software effectiveness; however, turtle age and plastron wear did not affect the accuracy of the photo-identification software. We concluded that Wild.ID can be used as a non-invasive photo-recognition technique for P. gorzugi in a short-term population study.

We report successful captive spawning and rearing of the highly endangered Moapa Dace, Moapa coriacea (approximately 650 individual fish in existence at time of this study). We simulated conditions under which this stream-dwelling southern Nevada cyprinid and similar species spawned and reared in the wild by varying temperature, photoperiod, flow, and substrate in 14 different spawning and rearing treatments in a propagation facility. Successful spawning occurred in artificial streams with the following characteristics: water flow directed both across the bottom gravel substrate into a cobble bed and across the upper water column; 12–14 fish/stream (0.016–0.026 fish/L depending on water level); static water temperature of 30–32°C; photoperiod of 12 h light and 12 h dark; gradual replacement of water from their natal stream with on-site well water; a combination of pelleted, frozen and live food; and minimal disturbance of fish. Nevada Department of Wildlife now uses these techniques successfully to produce fish in a culture setting. Identification of the effective combination of factors to trigger spawning in exceptionally rare fishes can be difficult and time consuming, and limiting factors can be subtle. Sufficient numbers of available test fish, close study and replication of wild spawning conditions, careful documentation, and patience to identify subtle limiting factors are often required to effectively rear and spawn fishes not previously propagated.

Curculionichthys scaius, new species, is distinguished from other congeners by having two usually conspicuous, somewhat triangular dark brown speckles lateral to the anal-fin origin, a pointed snout with paired rostral plates, numerous lateral abdominal plates, a single series of large median abdominal plates, numerous dentary and premaxillary teeth, and several morphometric proportions of the body and head, mostly involving prepelvic, prepectoral, and preanal distances, head and cleithral width, caudal peduncle length, and dorsal-fin spine. The new species represents the first record of the genus Curculionichthys in the Madeira River basin and is the most westerly distribution in the Amazon.

As DNA-based phylogenetic analyses have exploded, historically phenotype-based evolutionary hypotheses throughout the tree of life have been rewritten. However, rarely are DNA-based phylogenetic hypotheses tested via the reanalysis of phenotypic data. Skeletons representing all four recognized genera of the Guiana Shield endemic suckermouth armored catfish clade Lithoxini were examined to test a recently published DNA-based phylogenetic hypothesis using morphological evidence. Phylogenetic analysis of 54 mostly osteological characters yielded a single most parsimonious tree of 90 steps that was congruent with the molecular hypothesis: (Avalithoxus, ((Exastilithoxus), (Lithoxus, Paralithoxus))). Lithoxini was a well-supported clade with 20 synapomorphies, as was each of the genera within this clade. Avalithoxus jantjae, which was originally described in Lithoxus, was found to be missing the unique synapomorphies of Lithoxus Paralithoxus: a spoon-shaped, ventrally oriented process on the metapterygoid and a process on the preoperculo-hyomandibular ridge.