Adults Of Many Species Research Articles

An epigenomic shift in amygdala marks the transition to maternal behaviors in alloparenting virgin female mice.

Adults of many species will care for young offspring that are not their own, a phenomenon called alloparenting. However, in many cases, nonparental adults must be sensitized by repeated or extended exposures to newborns before they will robustly display parental-like behaviors. To capture neurogenomic events underlying the transition to active parental caring behaviors, we analyzed brain gene expression and chromatin profiles of virgin female mice co-housed with pregnant dams during pregnancy and after birth. After an initial display of antagonistic behaviors and a surge of defense-related gene expression, we observed a dramatic shift in the chromatin landscape specifically in amygdala of the pup-exposed virgin females compared to females co-housed with mother before birth, accompanied by a dampening of anxiety-related gene expression. This epigenetic shift coincided with hypothalamic expression of the oxytocin gene and the emergence of behaviors and gene expression patterns classically associated with maternal care. The results outline a neurogenomic program associated with dramatic behavioral changes and suggest molecular networks relevant to human postpartum mental health.

Water games by mountain gorillas: implications for behavioral development and flexibility-a case report.

Functions of play, which may be performed solo or in a social context, include motor training and behavioral flexibility. Play is often more common in infancy and the juvenile period, although it also occurs in adults of many species. In contrast to social play, few studies have investigated solitary play. Here, we present new empirical data on solitary water play in a subadult and two adult mountain gorillas in Bwindi Impenetrable National Park, Uganda, observed on three different days between January and February 2018. Focal sampling was used to record the behavior of the individuals interacting with water. Movements included vigorous rotation of the arms, splashing the water, tilting the head, making a play face, and sweeping with the hands to create waves on the water surface. One of the episodes represents the first vigorous display of splashing water ever reported for Bwindi gorillas. Our observations highlight three significant components of mountain gorilla development and behavior: play, behavioral flexibility, and exploration.

Infant Trauma Alters Social Buffering of Threat Learning: Emerging Role of Prefrontal Cortex in Preadolescence.

Within the infant-caregiver attachment system, the primary caregiver holds potent reward value to the infant, exhibited by infants’ strong preference for approach responses and proximity-seeking towards the mother. A less well-understood feature of the attachment figure is the caregiver’s ability to reduce fear via social buffering, commonly associated with the notion of a “safe haven” in the developmental literature. Evidence suggests this infant system overlaps with the neural network supporting social buffering (attenuation) of fear in the adults of many species, a network known to involve the prefrontal cortex (PFC). Here, using odor-shock conditioning in young developing rats, we assessed when the infant system transitions to the adult-like PFC-dependent social buffering of threat system. Rat pups were odor-shock conditioned (0.55 mA–0.6 mA) at either postnatal day (PN18; dependent on mother) or 28 (newly independent, weaned at PN23). Within each age group, the mother was present or absent during conditioning, with PFC assessment following acquisition using 14C 2-DG autoradiography and cue testing the following day. Since the human literature suggests poor attachment attenuates the mother’s ability to socially buffer the infants, half of the pups at each age were reared with an abusive mother from PN8–12. The results showed that for typical control rearing, the mother attenuated fear in both PN18 and PN28 pups, although the PFC [infralimbic (IL) and ventral prelimbic (vPL) cortices] was only engaged at PN28. Abuse rearing completely disrupted social buffering of pups by the mother at PN18. The results from PN28 pups showed that while the mother modulated learning in both control and abuse-reared pups, the behavioral and PFC effects were attenuated after maltreatment. Our data suggest that pups transition to the adult-like PFC social support circuit after independence from the mother (PN28), and this circuit remains functional after early-life trauma, although its effectiveness appears reduced. This is in sharp contrast to the effects of early life trauma during infancy, where social buffering of the infant is more robustly impacted. We suggest that the infant social buffering circuit is disengaged by early-life trauma, while the adolescent PFC-dependent social buffering circuit may use a safety signal with unreliable safety value.

Adults of the cerambycid beetleMegacyllene caryaeuse both olfactory and visual information to locate mates

AbstractMany species of beetles in the family Cerambycidae use volatile pheromones to facilitate the location of mates. Visual cues may also influence the location of mates, as the adults of many species of cerambycids are often brightly patterned and diurnal. Theory predicts that combining signals or cues of different modalities (e.g., chemical, visual) to transmit information will increase the likelihood of an organism responding to this information, compared to when the signal or cue is presented alone. Here, we test the hypothesis that attraction of adults of the cerambycid beetleMegacyllene caryae(Gahan) (Coleoptera: Cerambycidae, Clytini) to their pheromones will be increased when visual cues are present. Consistent with that hypothesis, the number of beetles caught by traps baited with pheromones was increased 3.4‐fold when a dead adult beetle of that species was attached to the trap, relative to those with just pheromone alone. Capture ofM. caryaein our study was also influenced by the position of traps within forest stands, with traps at 100 m within stands catching 2.5× as many beetles as traps at the forest edge. These findings suggest that vision and visual cues play an important role in the location of mates by cerambycid beetles and warrant further research. Also, the inclusion of visual cues on traps may enhance the efficacy of trapping cerambycid beetles, such as the detection of species that are non‐native and potentially invasive, or when monitoring species that are native and of conservation concern.

Planktonic Phases in Symbiotic Copepods: a Review

In symbiotic copepods, most naupliar stages are typically planktonic, playing a primary role in dispersal, while the first copepodid usually represents the infective stage. Later copepodid stages, including adults, are associated with host organisms. Many symbiotic copepods have abbreviated life cycles, with a reduced number of naupliar stages and two different feeding habits. These patterns are presumably related to distinct life cycles strategies. Exceptional cases are exemplified by members of the Monstrillidae and Thaumatopsyllidae, both of which are protelean parasites, with infective nauplii and non-feeding planktonic adults. In the Caligidae, the life cycle follows a generalized pattern, but adults of many species like Caligus undulatus seem to exhibit a dual mode of life involving host switching. Adults leaving the first host become temporarily planktonic before attaching to the final host. This dual mode of life is also found in adults of the Ergasilidae. Abbreviation of the planktonic phase is characteristic for some symbiotic taxa, thus suggesting that they have evolved to become highly efficient in locating and infecting new hosts without needing long-distance larval dispersal. The life cycle of copepods associated with zooplankters is also briefly reviewed. Zooplankters are clearly less used as hosts by copepods than benthic invertebrates. It is likely that symbiotic copepods dynamically utilize planktonic phases in their life cycle, thus maintaining the balance between dispersal, host location, reproduction, and predator-avoidance strategies.

Ground plan of the larval nervous system in phoronids: Evidence from larvae of viviparous phoronid.

Nervous system organization differs greatly in larvae and adults of many species, but has nevertheless been traditionally used for phylogenetic studies. In phoronids, the organization of the larval nervous system depends on the type of development. With the goal of understanding the ground plan of the nervous system in phoronid larvae, the development and organization of the larval nervous system were studied in a viviparous phoronid species. The ground plan of the phoronid larval nervous system includes an apical organ, a continuous nerve tract under the preoral and postoral ciliated bands, and two lateral nerves extending between the apical organ and the nerve tract. A bilobed larva with such an organization of the nervous system is suggested to be the primary larva of the taxonomic group Brachiozoa, which includes the phyla Brachiopoda and Phoronida. The ground plan of the nervous system of phoronid larvae is similar to that of the early larvae of annelids and of some deuterostomians. The protostome- and deuterostome-like features, which are characteristic of many organ systems in phoronids, were probably inherited by phoronids from the last common bilaterian ancestor. The information provided here on the ground plan of the larval nervous system should be useful for future analyses of phoronid phylogeny and evolution.

Exercise training reveals trade-offs between endurance performance and immune function, but does not influence growth, in juvenile lizards.

Acquired energetic resources allocated to a particular trait cannot then be re-allocated to a different trait. This often results in a trade-off between survival and reproduction for the adults of many species, but such a trade-off may be manifested differently in juveniles not yet capable of reproduction. Whereas adults may allocate resources to current and/or future reproduction, juveniles can only allocate to future reproduction. Thus, juveniles should allocate resources toward traits that increase survival and their chances of future reproductive success. We manipulated allocation of resources to performance, via endurance exercise training, to examine trade-offs among endurance capacity, immune function and growth in juvenile green anole lizards. We trained male and female captive anoles on a treadmill for 8weeks, with increasing intensity, and compared traits with those of untrained individuals. Our results show that training enhanced endurance capacity equally in both sexes, but immune function was suppressed only in females. Training had no effect on growth, but males had higher growth rates than females. Previous work showed that trained adults have enhanced growth, so juvenile growth is either insensitive to stimulation with exercise, or they are already growing at maximal rates. Our results add to a growing body of literature indicating that locomotor performance is an important part of life-history trade-offs that are sex and age specific.

TSPO as a target for treatments of diseases, including neuropathological disorders.

TSPO as a target for treatments of diseases, including neuropathological disorders.

Tracheal compression in pupae of the beetle Zophobas morio.

Insects that are small or exhibit low metabolic rates are considered to not require active ventilation to augment diffusive gas exchange. Some pupae with low metabolic rates exhibit abdominal pumping, a behaviour that is known to drive tracheal ventilation in the adults of many species. However, previous work on pupae suggests that abdominal pumping may serve a non-respiratory role. To study the role of abdominal pumping in pupa of the beetle Zophobas morio, we visualized tracheal dynamics with X-rays while simultaneously measuring haemolymph pressure, abdominal movement, and CO2 emission. Pupae exhibited frequent tracheal compressions that were coincident with both abdominal pumping and pulsation of pressure in the haemolymph. However, more than 63% of abdominal pumping events occurred without any tracheal collapse and hence ventilation, suggesting that the major function of the abdominal pump is not respiratory. In addition, this study shows that the kinematics of abdominal pumping can be used to infer the status of the spiracles and internal behaviour of the tracheal system.

Beetles (Coleoptera) of Peru: A Survey of the Families. Buprestidae

Buprestidae Diversity in Peru: 4 subfamilies, 12 tribes, 29 genera, 110 species and 3 subspecies. Recognition: Buprestidae are commonly called “jewel beetles” because of the spectacular colors of the adults of many species. Most buprestids are small to medium-sized beetles, although Euchroma gigantea is one of the largest Neotropical insects (55 mm). Adults display two extremes of morphology and ecology: members of one group are small (2–6 mm), rhomboidal, dorso-ventrally flattened, and mine leaves as larvae; the rest of the family are borers in wood or soft tissues and are larger (4–35 mm), elongate, and cylindrical or moderately flattened. Adults of many species are strongly shining and brightly metallic in coloration, a few are more or less covered by waxy yellow powder, and some have patterns formed by setae. Mimicry occurs in adults of both leaf-miners (models include chrysomelids and coccinellids; Hespenheide, 2014) and wood-borers (models include ants, flies and wasps; Hespenheide, 1986, 2010, 2012). Larvae are typically flattened with a large prothorax. Habitat: Members of the family occur primarily at low- to mid-elevations, below 2000–3000 m. Buprestids are most common in primary forest canopies, at forest edges, or in secondary growth, although a few species are found in open habitats on weeds and sedges. Adult behavior is related to larval feeding type. Wood-boring species are more numerous in areas of lower rainfall and a well-defined dry season and are usually found running on the trunks and branches of recently dead trees or branches, or feeding on leaves of their larval hosts. Adults are most active during the sunny weather during midday, and they fly readily, making them difficult to capture. Leaf-mining species are more common in areas with higher rainfall, and adults usually feed on the leaves of the larval host. Larval mines are usually full-depth and may be either serpentine or blotch-like in form, depending on the species. Except for some of the larger wood-boring species, most buprestids of both ecological types are apparently relatively narrowly host-specific and many appear to exist in very low populations. Many are associated with woody dicots, especially legumes, although leaf-miners are known from ferns and such monocots as sedges (Cyperaceae) and palms (Arecaceae). Pest species in Peru: Very few tropical species appear to be important agriculturally. Leaf-mining species (Leiopleura spp.) are associated with cassava or yuca (Manihot esculenta). The invasive Aphanisticus cochinchinae seminulum likely occurs on sugar cane, but neither appears to have much effect on the plants. Chrysobothris species have been reported as pests in plantations of woody plants.

Conspicuous calling near cryptic nests: a review of hypotheses and a field study on white‐browed scrubwrens

Predation is an important source of nest mortality in many bird species and calling near the nest can increase this risk, yet adults of many species regularly vocalize near their nests. Some of these calls serve clearly adaptive functions, such as alarm or provisioning calls. However, many species also give conspicuous ‘contact’ calls near the nest, which is puzzling because the function of these calls is unclear, and they might attract predators. Most studies of parental vocalizations near nests have focused on specific vocalizations and single hypotheses, yet there is a diversity of vocalization types and potential functions. We review the literature on the diversity and possible function of parental vocalizations near the nest, and then investigate the puzzle of conspicuous contact calling near nests by white‐browed scrubwrens Sericornis frontalis. In scrubwrens, ‘chip‐zz’ contact calls were almost always used when adults approached nests, and when they approached one another or changed location. Call composition also changed: the proportion of ‘chip’ elements increased as callers approached the nest or other adults. Neither adult sex nor nestling age affected calling. Thus, chip‐zz calls appear to be used as ongoing signals to other group members of the caller's activity and location, particularly relative to the nest. Nestlings appeared to use the calls as cues of adult arrival, and increased calling as adults approached nests. Further, adults called less after a predator was on the territory, suggesting that parents may be able to reduce the risk of chip‐zz calls betraying nest location, or possibly use the absence of calling as a signal of danger. This study thus demonstrates that calling near nests could inform both adults and nestlings about the caller's behaviour, and could serve multiple functions. Future studies will need to experimentally test these functions, as well as the other hypotheses reviewed here.

The Ontogeny and Evolution of Sex-Biased Gene Expression in Drosophila melanogaster

Sexually dimorphic phenotypes are thought to largely result from sex differences in gene expression, and genes with sex-biased expression have been well characterized in adults of many species. Although most sexual dimorphisms manifest in adults, many result from sex-specific developmental trajectories, implying that juveniles may exhibit significant levels of sex-biased expression. However, it is unclear how much sex-biased expression occurs before reproductive maturity and whether preadult sex-biased genes should exhibit the same evolutionary dynamics observed for adult sex-biased genes. In order to understand the continuity, or lack thereof, and evolutionary dynamics of sex-biased expression throughout the life cycle, we examined sex-biased genes in pre-gonad tissue of two preadult stages and compared them with the adult gonad of Drosophila melanogaster. We found that the majority of the genome is sex-biased at some point in the life cycle, with some genes exhibiting conserved sex-biased expression and others displaying stage-specific sex bias. Our results also reveal a far more complex pattern of evolution for sex-biased genes throughout development. The most rapid evolutionary divergence occurred in genes expressed only in larvae within each sex, compared with continuously expressed genes. In females—but not males—this pattern appeared to be due to relaxed purifying selection in larva-limited genes. Furthermore, genes that retained male bias throughout life evolved more rapidly than stage-specific male-biased genes, due to stronger purifying selection in stage-specific genes. However, female-biased genes that were specific to larvae evolved most rapidly, a pattern that could not be definitively attributed to differences in adaptive evolution or purifying selection, suggesting that pleiotropic constraints on protein-coding sequences can arise when genes are broadly expressed across developmental stages. These results indicate that the signature of sex-specific selection can be detected well before reproductive maturity and is strongest during development.

Effects of competition and egg predation on shelter use by Octopus tehuelchus females

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 482:141-151 (2013) - DOI: https://doi.org/10.3354/meps10237 Effects of competition and egg predation on shelter use by Octopus tehuelchus females Maite Narvarte1,2,*, Raúl Alberto González1,2, Lorena Storero1,2, Miriam Fernández3 1Consejo Nacional de Investigaciones Científicas y Técnica (CONICET), Av. Rivadavia 1917, C1033AAJ, Ciudad Autónoma de Buenos Aires, Argentina 2Instituto de Biología Marina y Pesquera Almirante Storni, Escuela Superior de Ciencias Marinas, Universidad Nacional del Comahue, Av. Güemes 1030, San Antonio Oeste 8520, Argentina 3Estación Costera de Investigaciones Marinas de Las Cruces, and Center for Advanced Studies in Ecology and Biodiversity, Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago, Chile *Email: mnarvarte@gmail.com ABSTRACT: Parental care in the ocean ranges from provision to eggs and embryos to protection from predators. In particular, nest attendance has several benefits associated with relatively higher survival rates, lower vulnerability to predation and parasitism, and faster development rates. The quality of shelters matters, and adults of many species have to compete for suitable shelters. Here, we studied whether shelter type for brooding and egg protection from predation could be a determinant of competition among adults in the cephalopod Octopus tehuelchus. To this end, we (1) assessed the abundance of different types of shelters and preference under field and laboratory conditions, (2) tested the effect of intraspecific competition for shelters, (3) estimated density of potential sources of embryo mortality, and (4) determined the role of female protection in egg survival against predators. We found that in areas where shelters for development are scarce, females compete with males for the most suitable shelters. Fecundity depends on the female size, and shelters with higher volume are preferably selected by females. Excluding the brooding female from shelters resulted in increased egg mortality due to predation by octopus males and removal by chitons. We suggest that, in this species, shelter availability poses a constraint to brooding and affects total parental investment in reproduction and predation risk on eggs. This constraint may also take place in other marine invertebrates with similar life history traits, especially in areas where shelter is limited. KEY WORDS: Shelter use · Competition · Predation on eggs · Octopus tehuelchus Full text in pdf format PreviousNextCite this article as: Narvarte M, González RA, Storero L, Fernández M (2013) Effects of competition and egg predation on shelter use by Octopus tehuelchus females. Mar Ecol Prog Ser 482:141-151. https://doi.org/10.3354/meps10237 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 482. Online publication date: May 22, 2013 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2013 Inter-Research.

Life-stage specific environments in a cichlid fish: implications for inducible maternal effects

Through environmentally induced maternal effects females may fine-tune their offspring’s phenotype to the conditions offspring will encounter after birth. If juvenile and adult ecologies differ, the conditions mothers experienced as juveniles may better predict their offspring’s environment than the adult females’ conditions. Maternal effects induced by the environment experienced by females during their early ontogeny should evolve when three ecological conditions are met: (1) Adult ecology does not predict the postnatal environmental conditions of offspring; (2) Environmental conditions for juveniles are correlated across successive generations; and (3) Juveniles occasionally settle in conditions that differ from the juvenile habitat of their mothers. By combining size-structured population counts, ecological surveys and a genetic analysis of population structure we provide evidence that all three conditions hold for Simochromis pleurospilus, a cichlid fish in which mothers adjust offspring quality to their own juvenile ecology. In particular we show (1) that the spatial niches and the habitat quality differ between juveniles and adults, and we provide genetic evidence (2) that usually fish of successive generations grow up in similar habitats, and (3) that occasional dispersal in populations with a different habitat quality is likely to occur. As adults of many species cannot predict their offspring’s environment from ambient cues, life-stage specific maternal effects are likely to be common in animals. It will therefore be necessary to incorporate parental ontogeny in the study of parental effects when juveniles and adults inhabit different environments.

Sexual signals, risk of predation and escape behavior

Adults of many species display extravagant sexual signals during the reproductive season, apparently evolved as a means of attracting mates or repelling potential competitors, thereby inadvertently also attracting the attention of predators. Many studies have shown predation costs of sexual display. Therefore, we should expect species with the most exaggerated signals to have evolved antipredator behavior that reduces or eliminates predation costs of sexual signaling but also to have evolved behavior that allows for escape from a predator once captured. We quantified 6 aspects of escape behavior in 2105 free-living birds belonging to 80 species when handled after capture for banding. Escape behavior was species specific as demonstrated by significant consistency in behavior among individuals. Escape behavior was significantly related to susceptibility to predation by cats Felis catus and goshawks Accipiter gentilis, showing that escape behavior is under current selection. Escape behavior was related to the ease of feather loss estimated in a previous study but also to the frequency of tailless individuals recorded in the field. Thus, escape behavior reported here was cross-validated against other aspects of antipredator behavior shown to reflect risk of predation. Aspects of escape behavior differed significantly between males and females (biting, fear screams, and feather loss). Sexually dichromatic species differed in escape behavior from monochromatic species by having a reduced frequency of fear screams and increased tonic immobility. These findings suggest that exposure to risk of predation has modified escape behavior in relation to sexual coloration. Key words: alarm calls, escape behavior, fear scream, predation, sex, signaling, tonic immobility. [Behav Ecol]

Coleoptera scarabaeoidea de la región de Teziutlán, Puebla, México

Con el propósito de evaluar la riqueza, abundancia y fenología de las especies de Coleoptera Scarabaeoidea o Lamellicornia de la región de Teziutlán, Puebla, se realizaron colectas mensuales entre mayo de 1999 y junio de 2000, en sitios con bosques de pino-encino-liquidámbar o zonas de cultivosituados entre 1,990 y 2,000 m de altitud. Se capturaron 2,082 ejemplares que representan a 59 especiesde 29 géneros, 18 tribus y 7 subfamilias de Melolonthidae, Scarabaeidae y Passalidae, entre las quedestacan Phyllophaga godmani (Bates), Isonychus piperitus Bates, Anomala terroni Morón, Chrysinaperuviana Kirby, Plusiotis aurofoveata Morón, Cyclocephala fasciolata Bates, Dynastes hyllus Chevrolat, Deltochilum mexicanum Bates, Ontherus mexicanus Harold, Onthophagus cyanellus Bates,Passalus punctatostriatus Percheron, Proculejus hirtus (Truqui) y Odontotaenius zodiacus Truqui. La riqueza específica es elevada y representativa de ese tipo de bosques a pesar de la perturbaciónexistente. Las especies más abundantes fueron Phyllophaga vetula (Horn), P. xanthe (Bates), Macrodactylus mexicanus Burmeister, Hoplia squamifera Burmeister, Cyclocephala jalapensis Casey,C. weidneri Endrodi, y Chrysina macropus Francillon. Los adultos de la mayor parte de las especies están activos entre abril y junio. De acuerdo con el índice de Simpson la fauna de lamelicornios deTeziutlán presenta un 80% de similitud con la fauna de las montañas del noreste de Hidalgo, un 33% con la región vecina de Cuetzalan, Puebla, y un 17% con el área de Los Tuxtlas, Veracruz. Se incluyeuna clave para separar las 59 especies encontradas.

Habitat utilization by coral reef fish: implications for specialists vs. generalists in a changing environment

1. The impact of environmental disturbance and habitat loss on associated species is expected to be dependent on a species' level of specialization. We examined habitat use and specialization of coral reef fish from the diverse and ecologically important family Pomacentridae, and determined which species are susceptible to declines in coral cover due to disturbance induced by crown-of-thorns seastar (COTS, Acanthaster planci L.). 2. A high proportion of pomacentrid species live in association with live coral as adults (40%) or juveniles (53%). Adults of many species had strong affiliations with branching corals, while juveniles favoured plating growth forms, reflecting the sizes of refuge provided by coral types. 3. Juveniles of species that associated with coral had narrower niche breadths than adult conspecifics, due to associations with specific coral types. The especially high coral association and narrower niche breadth of juveniles suggest that the presence of live coral is crucial for many species during early life history, and that disturbance-induced coral loss may have serious flow-on effects on adult abundance. 4. Microhabitat availability was a poor predictor of fish species abundance. Significant correlations between coverage of coral types and abundance of five adults and two juvenile species were detected; however, these relationships explained <35% and <10% of the variation in abundance of adult and juvenile species, respectively. 5. Niche breadth explained 74% of the variation in species' mean response to coral decline and it is clear that disturbance has a greater impact on resource specialists, suggesting that increasing frequency and intensity of coral loss will cause reef fish communities to become dominated by habitat generalists at the expense of coral-dwelling specialists.

Adaptations of dragonflies (Odonata) under desert conditions

Different types of adaptations of dragonflies to climatic conditions of the desert zone are described. The main habitats of the dragonfly nymphs are lotic and semi-lotic artificial reservoirs. The life cycles are synchronous with seasonal climatic changes, reproduction being restricted to periods of the optimal hygrothermal conditions. Some species reveal vertical seasonal migrations. The labile daily activity rhythms allow the dragonflies to avoid the effects of unfavorable conditions. Adults of many species emerge at night.

The Problem of Adult Play Fighting: A Comparative Analysis of Play and Courtship in Primates

Although play fighting, like play generally, is predominantly a feature of the juvenile phase, such behavior persists in the adults of many species. There are two major contexts in which adults engage in play fighting – with juveniles and with other adults. The least attention has been given to adult–adult play. However, one pattern that has been noted by several authors is that the most commonly occurring context of adult–adult play fighting is during courtship, and that this is more likely to occur in solitary species. Supposedly, such play could function to overcome the aggressiveness of potential pairmates unfamiliar with one another, or as a means of evaluating mate quality by one or both partners. By contrasting the presence and degree of play fighting during courtship with the degree of male–female familiarity, the hypothesis that the former is influenced by the latter is tested. Data on 35 species of primates, from 15 families, were compiled from the literature and compared using a method of independent contrasts that incorporates information on phylogenetic relationships. A significant regression was found, with the degree of male–female familiarity accounting for 40% of the variance in courtship play. Therefore, our data support the hypothesis that play fighting in courtship is influenced by male–female patterns of association. However, the data also indicate that other factors must influence the occurrence of play fighting amongst adults, not only during courtship, but also in nonsexual contexts. The broader context of adult–adult play in mammals is discussed.

Crithidia fasciculata:Isolation, Sequencing, and Expression of the Hypoxanthine-Guanine Phosphoribosyltransferase Gene

Individuals from 13 wild mammalian species collected in southwestern Tennessee were serologically positive for anti-Naegleria spp. antibodies (ANA). This is the first report of ANA in wild mammals. Interspecific differences in the occurrence of ANA and titers indicate that wild mammals have differing degrees of contact with Naegleria spp. based on ecological or behavioral adaptations, and possibly the innate ability of a species to produce ANA. Intraspecifically, it appears that if a mammal is exposed to Naegleria spp. in the environment, titers of ANA will not significantly differ, regardless of age or sex. Adults of many species had significantly higher occurrences of ANA. Populations of juvenile wild mammals are probably at higher risk than adults to naeglerial infection in the environment, not because of lower titers, but because their chance of having ANA is less than adults. Differences in the occurrence of ANA in wild mammals may also reflect how humans are exposed to Naegleria spp. in the environment.