Reproductive habitat selection—deciding where to mate and where to raise offspring—is a critical component of successful reproduction. Parents selecting sites to signal to or search for mates may, e.g., experience strong predation pressure, whereas their offspring may have to compete for food. Here we assessed how the presence of vegetation cover affects site selection for signaling and oviposition by Túngara Frogs (Engystomops pustulosus) and how this choice influences reproductive output in terms of tadpole survival and growth. We found males to call more often from artificial puddles covered with vegetation compared to open puddles in a large-scale field experiment. A follow-up mesocosm experiment revealed the pattern observed in the field to be the result of an active choice and not caused by selective predation. We found that the presence of foam nests was not related to vegetation cover, suggesting that some females actively move away from male call sites. Finally, we found tadpoles to grow heavier in vegetated compared to open puddles in a small-scale experiment. Our data show that male frogs prefer to display from vegetated sites, most likely to reduce risk of predation by eavesdropping predators, such as frog-eating bats. Alternatively, males prefer to call from vegetated sites to improve their offspring development and survival, although choice of breeding site appears to be largely under control of females. Call site choice thus appears to provide some adaptive benefits to males in terms of survival, whereas oviposition choice does not provide females with better developmental conditions for their offspring. Active avoidance of sites with calling males may, however, reduce tadpole competition, but future studies should reveal to what extend puddle quality is weighted against competition in female breeding choices. Our findings reveal that breeding site choice differs across the important life-history stages of mating and oviposition, and we argue that this can have important consequences for any conflict between the sexes.

The global population status of many reptiles, particularly tortoises as one of the most threatened tetrapod groups, necessitates conservation efforts and study. Baseline information about habitat use can help formulate conservation strategies and improve effectiveness of surveys. I studied habitat use by Karoo Dwarf Tortoises (Chersobius boulengeri), an endangered South African endemic with only one population known to contain males, females, and juveniles, to aid conservationists in assessing which nature reserves (with incidental records) and potential new reserves may sustain populations, and to inform surveys for additional populations. Available microhabitats and rock types were mapped using an unmanned aerial vehicle. I analyzed the tortoise distribution and determined home range sizes (minimum convex polygons) and minimum daily movement distances of nine males and 16 females using radio transmitters. All fieldwork was conducted in spring 2018 and 2019, and in summer 2018, 2019, and 2020. Relatively high numbers of tortoises inhabited sills (i.e., exposed dolerite intrusions between sandstone) that contained ample retreats among boulders and rocks, whereas relatively few lived on level plateaus that might expose them to predatory birds. Despite their apparent preference of sills, tortoises were able to survive in home ranges that contained little sill microhabitat. Tortoises were rather sedentary, having small sexually and seasonally similar home ranges (1.10–1.14 ha) and movement distances (27.6–28.4 m/day), although their home ranges were larger than those of the related Speckled Dwarf Tortoise (Chersobius signatus), possibly as a result of different habitat productivities. Conservationists and surveyors should consider that sills appear important for Karoo Dwarf Tortoises, but generic rocky slopes may also harbor individuals. Future studies could address aspects that underlie microhabitat use, such as availability of retreats and vegetation, and integrate available information in a spatial model.

In many animal species, alternative reproductive tactics can result in alloparenting: adult individuals providing care for juveniles that are not genetically their own progeny. In species with parental care, males may exhibit “sneaking” behavior and fertilize eggs in the nest of another male, or nesting males may commit egg theft from a more successful male, possibly to help attract females. Alloparenting may have important consequences for both male and female reproductive output and mate choice, but rates of such non-paternity in natural populations are poorly understood in many taxa, as are the ecological factors that might influence these rates. Here, we quantified the frequency of non-paternity between males and the eggs in their nests within 15 natural populations of Threespine Stickleback, and tested whether the frequency of mismatch was predicted by characteristics of the lake (lake size and nest density) or features of individual males (body size and diet) or their chosen nest location (depth and presence of vegetation). The frequency of non-paternity was relatively high across all lakes (23–66%) but was not explained by lake-level characteristics (lake area or nest density). Alloparenting was more likely for individual males with more benthic diets (as measured by stable isotopes) and for males whose nests were closer to vegetation, although this effect varied across lakes. Our results suggest that individual-level characteristics of the male and nest influence the frequency of alloparenting, and that variation among individuals and populations should be considered in studies of the genetics and evolutionary consequences of alternative reproductive tactics.

Suckermouth catfishes of the genus Chiloglanis are found throughout tropical Africa. Recent studies highlighted the diversity within this genus remains incompletely documented and nearly 20 new species have been described in the past ten years. Here we describe two new species of Chiloglanis from streams in the Upper Guinean Forest. Chiloglanis fortuitus, new species, is only known from one specimen collected in the St. John River drainage in Liberia and is readily distinguished from other species of Chiloglanis by the number of mandibular teeth and the length of the barbels associated with the oral disc. Chiloglanis frodobagginsi, new species, from the upper Niger River was previously considered to be a disjunct population of C. micropogon. A combination of several characters diagnoses C. frodobagginsi, new species, from topotypic C. micropogon in the Lualaba River (Congo River basin) and from Central African populations of Chiloglanis cf. micropogon in the Benue, Ndian, and Cross River drainages. The biogeographical implications of the recognition of C. frodobagginsi, new species, the likelihood of finding additional diversity in the streams of the Upper Guinean Forests, and the taxonomy of C. micropogon and C. batesii are also discussed.

Genomic data are increasingly used to understand the nature of species boundaries, which provides critical information about biodiversity and phylogeography. One example is the Greater Short-horned Lizard (Phrynosoma hernandesi), a wide-ranging species with substantial morphological and genomic variation throughout its range. Within the range of P. hernandesi, a miniaturized lizard was recently described as P. diminutum. Phrynosoma diminutum inhabits a distinct ecological region of Colorado in the San Luis Valley, but the unique location and size difference between P. diminutum and surrounding populations of P. hernandesi does not necessarily imply that P. diminutum is an independent evolutionary lineage. To determine whether genomic data support P. diminutum as an independent evolutionary lineage, we compared P. diminutum to surrounding populations of P. hernandesi using over 3,000 markers distributed throughout the genome. A phylogenetic analysis shows that P. diminutum is only weakly differentiated from nearby populations of P. hernandesi. Comparisons of genetic differentiation (fixation index, F_ST; genetic distance, D_XY) among five other closely related species of horned lizards provides further evidence that the low levels of genetic divergence observed in P. diminutum are reflective of population-level and not species-level divergence. Therefore, we propose that P. diminutum be placed in the synonymy of P. hernandesi rather than be recognized as a distinct species. Furthermore, we show how genomic data can be used to more accurately test species boundaries and avoid artificially inflating biodiversity estimates.

Australian species of the cirrhilabrin labrid genus Paracheilinus are reviewed. Four species of Paracheilinus are reported from Australian waters: P. amanda, new species, from Flora, Holmes, and Osprey Reefs, Coral Sea, off northeast Queensland, and Harrier Reef, Great Barrier Reef; P. filamentosus from Lizard Island, Great Barrier Reef; P. flavianalis from Evans and Flinders Shoals, Timor Sea, off northeast Darwin, Northern Territory, and Ashmore, Scott, Seringapatam, and Hibernia Reefs in the north-western shelf of Western Australia; and P. nursalim from Flinders Shoal, Timor Sea, off northern Darwin, Northern Territory. Paracheilinus amanda, new species, has previously been confused for P. rubricaudalis from Melanesia, but molecular analysis of mitochondrial COI recovers both species as reciprocally monophyletic lineages, differing from each other by 1–1.2% in genetic distance. They further differ in aspects of live coloration of terminal phase (TP) males. Both species are allopatric and do not overlap in distribution. The new species is described on the basis of six specimens: the holotype and two paratypes from Harrier Reef, Great Barrier Reef, one paratype from Flora Reef, Coral Sea, and from two paratypes collected off Hula in southern Papua New Guinea, along the north-western margin of the Coral Sea. The discovery of P. nursalim in Australia represents a new and significant range extension from previous locality records of West Papua and Ambon Bay. Paracheilinus is rediagnosed, and keys, diagnoses, photographs, and Australian distribution records are presented for all species herein.

Widespread losses in river connectivity and habitat degradation have led to rapid declines in migratory freshwater fishes. Large, connected tributary systems are likely critical to the conservation of fluvial species when they provide access to life-cycle-dependent habitats. The Blue Sucker (Cycleptus elongatus) is a large-bodied migratory catostomid, endemic to the large rivers of North America and declining in abundance across much of its range. Blue Suckers occupying the Wabash River (Illinois/Indiana, USA), a large tributary within the Mississippi River basin, may be one of few remaining robust populations of this species. To understand the characteristics of a successful Blue Sucker population, we analyzed data from ten years of electrofishing surveys conducted in the lower Wabash River (2010–2019, n = 563 Blue Suckers). We found Blue Sucker presence probability increased at sites with snags and with increasing surface water velocity. The length–weight regression was comparable to other populations, and the mean relative weight was 94.27. Maturation was estimated to occur at a minimum of 422 mm total length, around 2–3 years of age. We found support for variable individual spawning preparedness evidenced by inconsistent gonadal development among pre-winter adults and found support for intermittent reproductive success evidenced by a multi-modal population age structure. Genetic analysis supported the presence of a panmictic population throughout the Wabash River system, with no barrier to separate this population from the greater Mississippi River basin metapopulation. The effective population size was estimated to be 632.8 (95% CI = 318.4–4,492.2), indicating the population is not at immediate risk of inbreeding depression but should continue to be monitored. The characteristics of this resilient lower Wabash River Blue Sucker population can inform the management and conservation of this imperiled species throughout its range.

Since its description, Axelrodia lindeae has always been referred to as morphologically distinct from the remaining species of Axelrodia, with some authors questioning the monophyletic status of the genus. After a comprehensive analysis of representatives of Axelrodia, a new genus represented by A. lindeae as type species, plus two additional new species, is herein proposed. Besides its unique color pattern, characterized by two conspicuous midlateral stripes, the new genus is differentiated from the remaining characid genera by the dentary tooth row, implanted internally, and by the presence of a pseudotympanum crossed by a bundle of epaxialis musculature at its dorsal portion, dividing the pseudotympanum into two muscle hiatuses. Additionally, the phylogenetic relationships between the new genus and Axelrodia among the Characidae are presented.

Morphological variation is often maintained by complex and interrelated factors, complicating the identification of underlying drivers. Tadpole oral morphology is one such trait that may be driven by the independent and interacting effects of the environment and variation in developmental processes. Although many studies have investigated tadpole oral morphological diversity among species, few have sought to understand the drivers that underlie intraspecific variation. In this study, we investigated potential drivers of labial tooth number variation among populations of two species of tailed frogs, the Rocky Mountain Tailed Frog (Ascaphus montanus) and the Coastal Tailed Frog (A. truei). We counted labial teeth from 240 tadpoles collected across elevation (both species) and latitudinal (A. truei) gradients, providing a natural temperature gradient. We tested the effects of developmental stage and local temperature conditions on labial tooth number. We found that labial tooth number variation was independently affected by both developmental stage and local temperature, as well as the interacting effects of these two variables (pseudo-R² 5 67–77%). Our results also uncovered consistent patterns in labial tooth row formula across the ranges of both species; however, tadpoles of A. truei from northern British Columbia had a unique bifurcation of a posterior tooth row. This study highlights the diversity in intraspecific tadpole oral morphology and the interacting processes that drive it.

Trichomycterus puna, new species, is described from a small tributary of the Corral Blanco in Catamarca Province, Argentina, as part of an ongoing systematic study of the genus Trichomycterus from the High Andean Plateau or Altiplano-Puna drainages of the southern Central Andes. The new species is distinguished from congeners by the following characters: the odontodes embedded in thick integument that covers interopercle, the premaxillary bone smaller than maxilla, the presence of sesamoid supraorbital with lateral process, the supraorbital sensory pore s3 present, the discontinuous supraorbital sensory canal, 2–3 premaxillary tooth rows, the uniformly dark pigmentation on the trunk, 15 precaudal vertebrae, the skin of trunk with minute thread-like papillae, 7–8 pectoral-fin rays, 9–12 dorsal procurrent caudal-fin rays, 10–11 ventral procurrent caudal-fin rays, the distally unbranched barbels, the wider interorbital distance, 16 pairs of ribs, the first dorsal-fin pterygiophore inserting on vertebra 18, and the first anal-fin pterygiophore inserting on vertebra 21. It closely resembles T. alterus, T. belensis, T. boylei, and T. ramosus from the Puna region. Trichomycterus belensis and T. catamarcensis are recorded from new localities over 3,400 m elevation.

After a preceding revision based on 87 specimens, the systematics of the abyssal giant cuskeel genus Spectrunculus Jordan and Thompson, 1914 has been revisited, based on the examination of 34 additional specimens and new otolith shape data of the holotype of S. grandis. From the latter, a clear distinction in otolith ostium width could be found in specimens from the Atlantic, Southern Indian Ocean, and Southwest Pacific, which were formerly identified as S. grandis. Consequently, the new species, S. stenostio, is described, which has a narrower ostium when related to its length or to sulcus length and differs also in the combination of three body shape characters, three meristic characters, and maximum size from the three other congeners, S. crassus (Atlantic, East Pacific), S. grandis (Pacific), and the previously synonymized S. radcliffei (Pacific, Southern Indian Ocean, Southeast Atlantic). The latter species is here resurrected based on a rather short pre-anal length and additional morphometric as well as meristic and maximum size differences. An identification key for the four species of Spectrunculus is provided.