Gyrinophilus Porphyriticus Research Articles

Survival strategies of the salamander Desmognathus ochrophaeus: interaction of predator-avoidance and anti-predator mechanisms

Abstract. The anti-predator responses of the mountain dusky salamander, Desmognathus ochrophaeus, to the larger predatory salamanders, Dunn's spring salamander, Gyrinophilus porphyriticus, and black-bellied salamander, D. quadramaculatus were examined in two types of experiments. In both experiments the prey species, especially those corresponding to the largest size subject to predation by these predators, fled from G. porphyriticus but not D. quadramaculatus when seasonal predator avoidance was low. Fleeing from G. porphyriticus was low when seasonal predator avoidance was high. The high fleeing response to G. porphyriticus corresponded to low post-attack anti-predator efficacy against G. porphyriticus. The low fleeing response to D. quadramaculatus corresponded to high post-attack anti-predator efficacy against D. quadramaculatus.

Intraguild predation among larval plethodontid salamanders: a field experiment in artificial stream pools.

Intraguild predation can be important in determining community structure and dynamics. Artificial stream pools were used to test for the impacts of intraguild predation among three species of larval plethodontid salamanders. Intraguild predators (large Gyrinophilus porphyriticus and Pseudotriton ruber) significantly decreased the survival of small Pseudotriton ruber. There was a trend toward reduced growth of Pseudotriton and Eurycea cirrigera in the presence of intraguild predators. The presence of large Gyrinophilus significantly reduced the growth rate of large Pseudotriton, both in the absence and presence of intraguild prey. The presence of intraguild prey did not significantly increase the growth rates of the intraguild predators. Intraguild predation is likely to be an important force shaping the evolution and ecology of these salamanders.

Do the risks of predation and intermale competition affect courtship behavior in the salamander Desmognathus ochrophaeus?

Natural populations of mountain dusky salamanders, Desmognathus ochrophaeus (Amphibia: Caudata: Plethodontidae), may experience two types of risk during courtship encounters: interspecific predation, affecting both sexes, and intraspecific competition for mates, affecting males. We conducted two experiments in the laboratory to determine whether and how these two risks influence the outcome of male-female encounters. In experiment 1, courtship interactions resulting in spermatophore deposition were inhibited in the presence of a restrained species of salamander (Gyrinophilus porphyriticus) known to prey on D. ochrophaeus. Probability of successful courtship was not affected by the presence of a restrained species that is not predatory (Plethodon teyahalee). In experiment 2, courtship interactions resulting in spermatophore deposition were inhibited in the presence of two restrained conspecific males, but were unaffected in the presence of a single restrained male. We conclude that the dual risks of predation and intrasexual competition for mates have been significant selective factors in shaping the evolution of courtship decisions in Desmognathus ochrophaeus.

Ecological Interactions Among Predators in Experimental Stream Communities

Field observations on the effect of brook trout on an assemblage (sometimes described as a guild) of predatory salamanders suggest that the interactions among predators in small, headwater streams may be important in determining the structure of this assemblage of predators and thereby, the predation pressure felt by species at lower trophic levels. The interactions among predators and the potential role of those interactions in headwater stream communities was examined in 16 replicated experimental streams. I examined the ecological interactions among four species of co—occurring predators, adult Salvelinus fontinalis (98—122 mm standard length [SL]), larval Gyrinophilus porphyriticus (36—58 mm snout—vent length [SVL]), larval Eurycea bislineata (13—21 mm SVL), and Cambarus bartonii (6—17 mm carapace length [CL]), in an experiment that began in mid—June and ran for 3 mo. Brook trout affected both survival and growth of the larger salamander species, Gyrinophilus, and Salvelinus and Gyrinophilus affected the growth of the smaller salamander Eurycea and the crayfish Cambarus. The presence of Gyrinophilus had no effect on relative condition or fecundity of Salvelinus. Larger predators caused Cambarus and Eurycea to alter their activity levels and habitat, but Gyrinophilus made no adjustments to the presence of Salvelinus. Results demonstrate that Gyrinophilus is vulnerable to predation/aggression from brook trout, but that Eurycea Cambarus are able to behaviorally avoid predation by both large predators at a significant cost to growth. The effect of brook trout on the two species of salamander in the experimental streams parallels the observed differences between salamanders in trout and trout—free waters in the field. Thus, interactions among predators in headwater streams directly and indirectly influence population dynamics of the interacting species by affecting survival, growth, behavior, and habitat use. The interactions among these predators can determine, in part, the predation environment experienced by individuals at lower trophic levels.

Comment: Sexually selected infanticide among female birds

Prey may use multiple sensory channels to detect predators, whose cues may differ in altered sensory environments, such as turbid conditions. Depending on the environment, prey may use cues in an additive/complementary manner or in a compensatory manner. First, to determine whether the purely aquatic Barton Springs salamander, Eurycea sosorum, show an antipredator response to visual cues, we examined their activity when exposed to either visual cues of a predatory fish (Lepomis cyanellus) or a non-predatory fish (Etheostoma lepidum). Salamanders decreased activity in response to predator visual cues only. Then, we examined the antipredator response of these salamanders to all matched and mismatched combinations of chemical and visual cues of the same predatory and non-predatory fish in clear and low turbidity conditions. Salamanders decreased activity in response to predator chemical cues matched with predator visual cues or mismatched with non-predator visual cues. Salamanders also increased latency to first move to predator chemical cues mismatched with non-predator visual cues. Salamanders decreased activity and increased latency to first move more in clear as opposed to turbid conditions in all treatment combinations. Our results indicate that salamanders under all conditions and treatments preferentially rely on chemical cues to determine antipredator behavior, although visual cues are potentially utilized in conjunction for latency to first move. Our results also have potential conservation implications, as decreased antipredator behavior was seen in turbid conditions. These results reveal complexity of antipredator behavior in response to multiple cues under different environmental conditions, which is especially important when considering endangered species.

Toxicity in the plethodontid salamanders Pseudotriton ruber and Pseudotriton montanus (Amphibia, Caudata)

Pseudotriton ruber and P. montanus possess a proteinaceous skin toxin of mol. wt greater than 200,000. In terms of toxicity and amount present in the skin, pseudotritontoxin is comparable to tetrodotoxin, the other toxin in North American salamanders. The pharmacological action of pseudotritontoxin on mice includes the distinctive symptoms of hyperextension of hind legs and lower back, extreme irritability, severe hypothermia, quiescence, prolonged debility, and coma, with time-to-death of an ld 50 dosage from 12 to 48 hr. Larger doses cause an increase in severity symptoms with convulsions and death occurring at 1 hr or more. In contrast, lethal doses in young chickens cause convulsions and death in a few minutes. The concentration of toxin is greatest in the back skin, being five times that of belly skin, 35 times that of the gut, 18 times that of the liver, and 17 times that of the ovaries. Pseudotritontoxin is the first toxin to be identified in the Plethodontidae, the largest family of salamanders with over 200 known species. It is unusual in being one of the few amphibian poisons of high mol. wt. It also necessitates a re-examination of the mimetic relationships among the red eft, Notophthalmus viridescens, the red salamander, P. ruber, the midland mud salamander, P. montanus diastictus, and the spring salamander, Gyrinophilus porphyriticus. The best interpretation of this mimicry seems to be that of a Müllerian complex with a spectrum of unpalatability among the species.

The Effectiveness of Antipredator Secretions and Behavior of Selected Salamanders against Shrews

A total of 520 salamanders of 7 species were offered to short-tailed shrews, Blarina brevicauda, to assess the antipredator value of salamander skin secretions. Desmognathus ochrophaeus were fully palatable. Eurycea bislineata, Plethodon cinereus, P. jordani from two populations, P. glutinosus, Ambystoma maculatum and Gyrinophilus porphyriticus survived significantly more often that D. ochrophaeus and are, therefore, considered to be distasteful to shrews. Shrews used significantly more time to kill noxious species than the palatable one. Each salamander species exhibited antipredator postures in response to approach and biting by the shrew. The postures of the noxious species always involved elevation and undulation or lashing of the tail. This activity places the tail dorsum and its concentration of granular glands in proximity to the attacking shrew. B. brevicauda exhibited behavior patterns (e.g., mouth pawing, squeaking and avoidance) confirming the noxiousness of the presumed distasteful salamanders after biting them.

New localities for the Northern Spring Salamander and the Four-toed Salamander in southwestern Quebec

New localities for the Northern Spring Salamander and the Four-toed Salamander in southwestern Quebec

Sperm associations in the male reproductive tract of Eurycea longicauda (Amphibia: Caudata).

Characteristic sperm associations of various patterns and complexities have been reported in the male genital tracts of several mammals (Martan, 1970; Martan, Hruban & Brown, 1971). Koehring (1925, p. 253), in describing the spermatheca of female Eurycea bislineata, noted spermatozoa in dense whorls and stated (without clarification) that they were "similar to the groups found in the vas deferens of the male." Whorled configurations of spermatozoa have been reported in the spermathecae of Desmognathus fuscus (Marynick, 1971), Notophthalmus viridescens (Benson, 1968) and Gyrinophilus porphyriticus (Dieckmann, 1927) and illustrated, but not discussed, in the vasa deferentia of Ambystoma maculatum (Baker & Taylor, 1964) and Gyrinophilus porphyriticus (Strickland, 1966). These indications of aggregating spermatozoa in salamanders encouraged us to examine in detail the development of complex sperm associations in the vas deferens of the long-tailed salamander, Eurycea longicauda.

An Analysis of the Feeding Ecology of the Salamanders (Amphibia, Urodela) of the Hubbard Brook Experimental Forest, New Hampshire

The gut contents of 486 salamanders representing all five species (Plethodon cinereus, Desmognathus fuscus, Eurycea bislineata, Gyrinophilus porphyriticus, and Notophthalmus viridescens) occurring in the northern hardwoods forest of central New Hampshire were analyzed. These data show that there is broad niche overlap in the feeding ecology of the five species but spatial (habitat) separation, and gradients in size of adult salamanders effectively reduce competition for food resources. The food habits of all five species in the forest are described in detail. Generally, all five species are euryphagic predators and feed on any food they can capture in the proper size category.

Salamander Populations and Biomass in the Hubbard Brook Experimental Forest, New Hampshire

There were about 2950 salamanders per ha (1770 g/ha wet wt) in the Hubbard Brook Experimental Forest in New Hampshire. The terrestrial species, Plethodon cinereus, accounted for about 93.5% of the total biomass while the streamside species, Desmognathus fuscus, Eurycea bislineata and Gyrinophilus porphyriticus, accounted for the remaining 6.5%. Notophthalmus viridescens was present, but was rare and insignificant in the biomass calculations. The population size of salamanders at Hubbard Brook appears to be stable. The biomass of salamanders is about twice that of birds during the bird's peak (breeding) season and is about equal to the biomass of small mammals.

Interaction between competition and predation in cave stream communities

Predation by salamander larvae (Gyrinophilus porphyriticus) reduces the density of one of its prey (the isopod Asellus recurvatus) but increases the density of the other (the amphipod Crangonyx antennatus in a Virginia cave stream. This happens because predation on the isopod reduces its competitive effect on the amphipod. Both prey populations tend to occur more frequently in refugia when predators are present. In another cave where there are no prey refugia, the predator reduces the density of both species. It appears that it is easier for a predator to invade a community than to reach a stable equilibrium with the prey, if the prey have refugia, persistence of the prey system and the predator/prey system is constrained more by low population sizes than by the instability of the interaction coefficients.

Feeding behavior of the salamander Gyrinophilus porphyriticus in caves

The feeding responses of salamander larvae (Gyrinophilus porphyriticus) from caves in the Powell Valley in Virginia were investigated in the laboratory. The larvae locate prey by mechanoreception and capture the prey by a rapid sucking action, much like cave-limited salamanders do. Feeding success is greater with the isopod Asellus recurvatus (about 90 per cent) than with the amphipod Crangonyx antennatus (about 50 per cent), and this largely accounts for the higher frequency of A. recurvatus taken in choice experiments. G. porphyriticus readily ingested the unfamiliar isopod Lirceus usdagalun, but it took four weeks before it was digested as well. Small larvae tend to take small prey and large larvae take both large and small prey. Occasionally, larvae lunged at prey, which was usually unsuccessful. This behaviour seems to be a holdover from an evolutionary history in epigean environments where vision could be used to locate prey.

Feeding Experiments with a Supposed Mimetic Complex in Salamanders

The supposed mimetic complex consisting of the red- cheeked salamander, Plethodon jordani, and the red-cheeked variants of the Allegheny Mountain salamander, Desmognathus ochrophaeus, was tested by subjecting members of this complex to laboratory predation by four natural predator species. Predation by the eastern garter snake, the large short-tailed shrew, the Blue Ridge spring salamander, and the black-bellied salamander failed to reveal discriminatory feeding behavior. The possibility that mimicry has not been involved in the evolution of the red cheek patch in D. ochrophaeus remains. The hypothesis that infrequent but discriminate predation by uncommon predators such as birds could confer slight selective advantage upon the D. ochrophaeus the range of red-cheeked P. jordani the incidence of the red cheek coloration among normally patterned D. ochrophaeus is low. Numerous individuals have suggested that the similarity can be best explained in terms of mimicry. According to the theory of Bate- sian mimicry, the red cheek patch of P. jordani (the model) could be considered warning or aposematic coloration, which would ad- vertise to, predators some distasteful or undesirable quality. Huheey (1960) suggests that this undesirable characteristic is a slimy exuda- tion from the tail, not found in D. ochrophaeus. The red-cheeked variant of D. ochrophaeus (the mimic), which exhibits pseudapose- matic or false warning coloration, would thus gain survival value from its close resemblance to the model, even though it possessed none of the undesirable qualities. In Miillerian mimicry, both P. jordani and the red-cheeked D. ochrophaeus would possess unde- sirable qualities and thus the model and the mimic are both protected by undesirable characteristics. In the study of any suspected mimicry complex, the determina- tion of a natural predator that discriminates between the supposed mimics and nonmimetics is of utmost importance. If one can ascer- tain the natural predators of the models and mimics by field obser- vations or stomach analyses, and then prove the discriminating behavior of at least one such predator, he greatly strengthens the hypothesis 147

The Amphibia of Wayne County, Ohio

During the spring months of 1957-1962 and the academic year of 1959-1960, a survey of the amphibians of Wayne County, Ohio, was conducted. Collecting trips were initiated when ice began to melt on the ponds and were coordinated with spring rains. Trips to the more productive areas were made more often and collecting was more extensive and intensive in these localities (see Figure 1). The less productive areas proved to be in the southeastern part of the county, where local farmers have cleared the land surface extensively. Land not under cultivation is utilized as pasturage for livestock and has been stripped of woods and debris. Natural ponds contain little marginal vegetation suitable for even the smallest of local frogs Only the most ubiquitous amphibians have been collected in this part of the county. Eurycea bislineata and Desmognathus fuscus inhabit the streams and Rana pipiens, R. clamitans and Bufo americanus are undoubtably present. However, species which require woodlands, and the breeding ponds associated with them, can be expected to show spotty distributional patterns, if they are present at all. Specimens collected were placed in the museum of the Biology Department, College of Wooster (CW; Ur Urodela, An Anura) and the Museum of Zoology, The University of Michigan, Ann Arbor (UMMZ). For completeness, literature records of specimens not personally examined have been included. The following collections are represented: Ohio State Museum (OSM), Stone Laboratory, Ohio State University (SL), Cleveland Museum of Natural History (ZF), and Wilmington College (WC). A combination of all reports (Bishop, 1943; Walker, 1946; Conant, 1958) indicates that the following amphibians can be expected to occur in Wayne County. Taxa prefaced with an asterisk have not yet been taken: Necturus maculosus, *Cryptobranchus alleganiensis, Notophthalmus viridescens, *Ambystoma jeffersonianum, A. texanum, *A. opacum, *A. tigrinum, A. maculatum, Plethodon glutinosus, P. richmondi, P. cinereus, Desmognathus fuscus, Hemidactylium scutatum, *Gyrinophilus porphyriticus, Eurycea bislineata, E. longicauda, Pseudotriton ruber, Rana clamitans, R. sylvatica, R. pipiens, R. palustris, R. catesbeiana, Pseudacris triseriata, *Acris crepitans, Hyla versicolor, H. crucifer, Bufo americanus, B. woodhousei.

On the Constrictor Dorsalis Muscles of Sphenodon

tionship among species. The primary basis for establishing genera is morphological distinctiveness; however, it is usually supplemented by data on ontogeny, behavior, mode of life, adaptive trends within the group, etc. In view of the numerous, fundamental differences in morphology, ontogeny, and ecology discussed in this report, the genus Gyrinophilus is valid. Such recognition best indicates the relationship of these animals to other plethodontids. Acknowledgments. -We are grateful to Charles F. Walker, University of Michigan Museum of Zoology, for making available specimens of Hemidactylium scutatum and Plethodon glutinosus; to Dave Wake, University of Southern California, and to Doris M. Cochran, U. S. National Museum, for specimens of Gyrinophilus porphyriticus; and to Albert P. Blair, University of Tulsa, and James N. Dent, University of Virginia, for the specimens of G. palleucus.

American Caudata. III. The Status of Pseudotriton montanus in Ohio

The presence of Pseudotriton montanus ssp. in Ohio was first reported by Walker (1933: 224), on the basis of specimens in the Ohio State Museum. Subsequently, Bishop (1941: 14) described Pseudotriton montanus diastictus from Carter County, Kentucky, and various West Virginia stations, and later extended the range of this race to include southern Ohio to the exclusion of other forms of P. montanus (1943: 386; map 45). As matters stand today, most workers follow Bishop in considering diastictus the only representative of I seudotriton montanus in Ohio. That the salamanders of southern Ohio do not fit readily into any arrangement predicated largely on specimens from adjacent areas is not surprising. The region is poorly represented in most herpetological collections, although it has been an increasingly fruitful source of novelties within the past fifteen years, yielding such unusual and important records as: the allotype and many paratypes of Plethodon ricbmondi (Netting and Mittleman, 1938), the type of Gyrinophilus porphyriticus inagnoscus (Mittleman, 1942), and the only known Ohio specimens of Plethodon wehrlei (Walker, 1933), Leiolopisma utnicolor (Stupka, 1933), and Scaphiopus h. holbrookii (Gier, 1945). This general region forms the northern and western range limit of many caudate genera and species, such as Gyrinophilus, Pseudotriton, Aneides aeneus, and Plethodon richmondi. These terminal populations are often perceptibly different from others within the range of their species, although they are not always recognizable taxonomically. Taxonomic treatments of groups including forms occurring in this region are likely not to be consonant with local conditions, unless specific attention has been given to specimens collected in southern Ohio. The status of Pseudotriton montanus ssp. is an excellent case in point. Our collecting experience in southern Ohio has produced many specimens of montanus thoroughly distinct from diastictus, at least as compared with large series of topotypic specimens from northern Kentucky, but we have seen and collected other specimens indistinguishable from diastictus. In an effort to determine the status of these Ohio specimens, we have reviewed the extant

Amphibians and Reptiles of Northeastern Kentucky

the hills are forested with beech, chestnut, oak, pitch and scrub pine, walnut, and sweet and black gum, much of this forest being second growth timber injured by frequent burning. There are a number of caves in the area, particularly in Carter County, where Carter and Cascade Caves are located. Garman (1894) published a preliminary list of the vertebrate animals of Kentucky. For the entire state he listed fifteen amphibians and twentyfive reptiles. Funkhouser (1925) in his Wild Life in Kentucky listed forty reptiles. Dury and Williams (1933) list fifty-two amphibians and reptiles for the state. None of the various scattered records of Kentuckian amphibians and reptiles which have appeared in recent years deal with Rowan County. The apparent shortage of records for eastern Kentucky has stimulated the biological staff of the State Teachers College, Morehead, to make natural history surveys in the vicinity of Morehead, in Rowan County. The senior author has completed a study of the fishes of the Licking River drainage, and, in conjunction with D. E. Sollberger, a study of the mammals of the section. The present paper is the third in the series of studies of the vertebrates of northeastern Kentucky. The specimens obtained during the present survey were deposited in the Biology Museum at the Morehead State Teachers College. A list of the species taken during the present survey follows: Necturus maculosus maculosus (Rafinesque).-Common in the streams of the Licking River drainage. Cryptobranchus alleganiensis (Daudin).-Very common in Triplett and Licking rivers. It is often caught by local fishermen on trot-lines, and is easily taken at night in the smaller streams by the use of a flashlight. Triturus viridescens viridescens (Rafinesque).-Fairly common throughout the area; taken at Morehead and at Carter Caves. Ambystoma maculatum (Shaw).-Taken from ponds near Morehead in late February when breeding begins. Common, but seldom seen during the summer. Ambystoma opacum (Gravenhorst).-Several taken from beneath stones at Morehead. One was also obtained from Morgan County. Ambystoma texanum (Matthes).-Taken under rocks in a moist, low lying meadow near Morehead, and also in a dry pasture. Not very common. Plethodon cinereus (Green).-Very common in shady woodlands beneath decaying stumps and logs. Taken at various stations in Rowan and Carter counties. Plethodon glutinosus (Green).-Very common in shady places. It is most frequently found beneath stones along creek banks. Many were obtained in Rowan and Carter counties. Gyrinophilus porphyriticus duryi (Weller).-Taken at Carter Caves in X-Cave within a few miles of the type locality, and also along North Fork of Triplet Creek near Morehead.

The morphology of the aortic arches in four genera of plethodontid salamanders

AbstractThe larval, metamorphosing and definitive aortic arches of Desmognathus fuscus, Plethodon cinereus, Eurycea bislineata, and Gyrinophilus porphyriticus, described in this paper, were investigated because it was thought possible that, if the fourth or pulmonary arch failed to develop in these lungless forms, a new factor associated with the loss of lungs might be revealed.The salient points of structure disclosed, so far as the problem involved is concerned, are: D. fuscus and P. cinereus develop fourth arches which remain functional in the larvae and adults and supply the pharynx, oesophagus, stomach and skin of the shoulder region. In some instances the fourth arch in the larvae of P. cinereus is reduced in length or entirely lacking in which cases correspondingly less of the fourth arch and more of the third arch is present in the adult. E. bislineata and undoubtedly G. porphyriticus fail to develop fourth arches and hence do not possess these in either the larval or adult states.It is concluded, therefore, that the failure of the fourth arch to develop has evidently not been a factor involved in the advent of lunglessness in plethodontid salamanders. Also, the fact that E. bislineata never develops a fourth arch, yet is able to transform, furnishes additional evidence against Figge's view that Necturus fails to metamorphose because the ventral portion of the fourth arch is absent.

A New Locality Record for Gyrinophilus porphyriticus (Green) in Massachusetts

A New Locality Record for Gyrinophilus porphyriticus (Green) in Massachusetts