Ichthyology & Herpetology Volume 108: Issue 1

The Tule Perch, Hysterocarpus traskii, is a viviparous and externally monomorphic, internally fertilizing fish. Despite appearing monomorphic, males and females are expected to differ in body shape because the different reproductive roles occupied by the sexes should influence patterns of selection and, ultimately, lead to differences in morphology. The objectives of this study were to determine if the Sacramento–San Joaquin subspecies of Tule Perch (H. t. traskii) exhibit (1) sexual dimorphism in body shape, (2) size-related changes in body shape, and (3) sexual size dimorphism. Geometric morphometric analyses indicated that H. t. traskii exhibited significant sexual dimorphism of body shape and identified the mid-body and caudal peduncle regions as the most effective discriminators between the sexes. Females were narrower through the caudal peduncle and mid-body and had anal-fin origins that were more posteriorly located than males. Additionally, H. t. traskii exhibited significant size-related changes in body shape. Larger fish were deeper bodied with blunter snouts and wider caudal peduncles. The eyes of larger fish were relatively smaller and located higher on the body than those of smaller fish. Hysterocarpus t. traskii did not exhibit differences between the sexes in standard length, but males were significantly heavier than females.

Dispersal and nesting philopatry are two processes that affect the connectivity, evolution, and long-term viability of populations, and thus have important conservation implications for threatened and endangered species. Here we investigate dispersal, relatedness, and the fine-scale spatial genetic structure of Eastern Box Turtles (Terrapene carolina carolina) at the northern extreme of their geographic range in northwestern Michigan. We analyzed georeferenced microsatellite genotypes (n = 165) using global, sex-specific, and two-dimensional local spatial autocorrelation (2D LSA), as well as spatial principal components analysis (sPCA). Genetic diversity was low relative to Eastern Box Turtle populations in the middle of the range. We found dispersal was male-biased, as only females showed significant positive spatial genetic autocorrelation at distances less than 2 km. 2D LSA showed local genetic “hotspots” of related turtles that tended to correspond with known nesting areas. We found evidence for global genetic structure using sPCA, which we attribute to genetic clustering rather than clinal variation. Our results suggest that restricted female dispersal and fidelity to limited open-canopy nest sites result in fine-scale spatial genetic structuring in this population. We stress the importance of maintaining high quality nesting habitat and habitat corridors for transient males, which appear to be critical for functional connectivity of Eastern Box Turtles.

In freshwater turtles, movements have been shown to be influenced by seasonal changes in water levels, with members of the family Podocnemididae exhibiting some of the longest nesting migrations yet documented. In this study, we quantified linear home range sizes and seasonal movements of the Magdalena River Turtle (Podocnemis lewyana) using capture–mark–recapture and radio-telemetry techniques. We marked 924 turtles and recaptured 7.8% of these individuals one or more times, thereby documenting the movements of 41 juveniles, 13 males, and 18 females. Turtle movements differed significantly among sex/size classes, with males moving more. While 85% of all individuals had estimated linear home range sizes of less than 1 km, one juvenile moved 3.1 km, one female moved 2.5 km, and one male moved 4.8 km. We also obtained data on the movements of six reproductively mature females using radio telemetry. We documented seasonal movements out of channels into wetland or riverine habitats, increasing the estimates of total distance traveled for this sex/size class to a mean of 13.8 km (range = 6.9–18.7 km), with greater displacements documented during low water periods. Together, our results show that individuals of P. lewyana in the middle Magdalena River drainage occupy limited linear home ranges, but that reproductively mature females make extensive displacements during low water periods, presumably related to their need to access nesting beaches in riverine habitats. There are currently no protected areas within the range of this endemic species, but our results argue that any reserve created for protecting this critically endangered turtle must be large enough to cover all of its habitat requirements, including nesting beaches in the dry season that are separated from habitat where they maintain stable home ranges during the remainder of the year.

ABUNDANCE

Rana sierrae 664

ACTIVITY

Rhinella marina (tail clipping/swimming) 71–76

Testudo graeca (spatio-temporal) 332–338

Turtles (road barriers) 92–98

AGE

Culaea inconstans (recalculation) 124–129

Noturus stanauli (class structure) 447–450

Plethodon montanus 623–628

ALLOMETRY

Etheostoma cyanorum 214

Sceloporus formosus 475–478

ANATOMY (see MORPHOLOGY)

AWARDS/HONORS

Best papers (2018) 388

Fitch, Gibbs, Nelson, Johnson, Spiritus, Herp. Teach., Ich. Teach., Honorary Foreign 1–9

BEHAVIOR

Ambystoma bishopi (migration) 270–274

Anolis carolinensis (social stress) 653–657

Chelonia mydas (hatchling calls) 120–123

Dermochelys coriacea (hatchling calls) 120–123

Lepidochelys olivacea (hatchling calls) 120–123

Lithobates grylio

NEW NAMES

Aneides caryaensis 748–763

Atractus marthae 251–258

Baryancistrus

hadrostomus 481–492

micropunctatus 481–492

Channa lipor 61–70

Crocodylus halli 517–523

Gymnotus darwini 145–150

Moenkhausia bellasomniosa 232–237

Parmaturus angelae 314–322

Parotocinclus adamanteus 597–605

Polemon ater 24–32

Pomacentrus vatosoa 323–331

Pristella ariporo 439–446

Pseudobatos buthi 451–463

Scutiger tengchongensis 10–21

Sturisomatichthys

guaitipan 764–806

reinae 764–806

varii 764–806

NEW AND ESTABLISHED NAMES

Abies balsamea 94

Abudefduf sordidus