Ventral Contact Research Articles

Late Pleistocene freshwater fish (Cottidae) trackways from New England (USA) glacial lakes and a reinterpretation of the ichnogenus Broomichnium Kuhn

New trace fossil material from Late Pleistocene glaciolacustrine varves of the Connecticut River Valley, New England, USA represent the first evidence of freshwater sculpin in glacial Lake Hitchcock. Paleobiogeographic data constrain the timing of the last reinhabitation of freshwater cottids from a Wisconsinan glacial refugium. Freshwater sculpin were present in the area of study by ~ 13.7 ky BP, moving approximately 400 km in 5000 yr, and following the ice margin at distances as close as 35 km. The trace fossils warrant erection of a new ichnospecies, Broomichnium flirii isp. nov. Comparison of this new ichnospecies to Broomichnium permianum reveals distinct similarities, and it is possible that the Permian examples of B. permianum also were made by fish, which would reconcile a long-running controversy. Many groups of fish are demersal and make ventral body contact with the substrate and could potentially leave similar traces. Identifying new forms of trace fossils made by fish that use alternative modes of locomotion will prove useful in paleoenvironmental interpretations.

The naso-frontal joint in snakes as revealed by high-resolution X-ray computed tomography of intact and complete skulls

The naso-frontal joint of snakes is described on the basis of high-resolution X-ray computed tomography scans of single individuals of spirit-preserved snake specimens. The suspension of the snout unit from the braincase at the naso-frontal joint shows some broad evolutionary trends among snakes with potential phylogenetic implications, such as sutured or fused medial frontal flanges formed by the medial frontal pillars and the frontal subolfactory processes (in alethinophidians), the restriction of the usually extended dorsoventral contact of the medial nasal flange with the medial frontal flanges to a dorsal or ventral contact (in macrostomatans), and the transfer of the main element of snout suspension from the nasal to the septomaxilla (in colubroids). Some phylogenetic implications of the morphological characters identified in this study are outlined and discussed.

The structure of the sarcopterygian Onychodus jandemarrai n. sp. from Gogo, Western Australia: with a functional interpretation of the skeleton

ABSTRACTA description of the head, mandible, pectoral girdle, humerus, medial fins and their supports, and the dissociated vertebral column has been prepared for Onychodus jandemarrai n. sp. from the Gogo Formation (Frasnian) of Western Australia. This is the most completely known species of the genus. The feature influencing most of the head morphology is the retractable parasymphysial tusk whorls. Their presence has caused a reorganisation of the braincase, palate (including the loss of the vomers), and lateral displacement of the nasal capsules. The extensive mandibular articulation is in cartilage, and the mandibular symphysis is weak. This makes for a kinetic skull. There is a single submandibular on each side. The vertebral column is poorly ossified, consisting of intercentra which have no ventral contact, and pleurocentra. The neural arches have no longitudinal ligament, have unequal sides, and asymmetrical placing of the dorsal and ventral nerve root foramina. Each arch has an anterior surface that often attaches to the next anterior arch. The caudal fin is almost diphycercal; all the medial fins have strong support structures. An attempt is made to discuss the functional morphology of many features of the skeleton.

Comparing maternal styles in bonobos (Pan paniscus) and chimpanzees (Pan troglodytes)

Studies on Cercopithecine primate maternal styles, using factor analysis on a set of maternal behaviors, commonly render two factors that describe separate dimensions of maternal behavior: protectiveness and rejection. The aims of this study were to 1) investigate whether this method for determining maternal styles in Cercopithecine species can be applied to bonobos (Pan paniscus) and chimpanzees (Pan troglodytes), 2) determine whether they follow the same pattern, and 3) assess whether species differences in maternal style are apparent. We performed a factor analysis on nine maternal behaviors using data on eight mother-infant pairs of each species. This resulted in three factors: protectiveness, distance, and refusal. Protectiveness is positively correlated with time spent in ventral contact, making contact, approaching, and restraining. Distance is positively related with breaking contact and leaving. Refusal is positively correlated with rejecting and nipple-rejecting. The pattern of protectiveness corresponds with the pattern found in Cercopithecine species, suggesting a high consistency of this dimension across species and higher taxa. The retention of the other two factors indicates that in the Pan species, breaking contact and leaving represent another dimension, apart from rejecting and nipple-rejecting, which usually fall under one dimension in Cercopithecine species. An interspecific comparison of the factor scores for each dimension of maternal behavior reveals that, on average, bonobos and chimpanzees score equally on protectiveness. Scores on distance increase positively with infant age in chimpanzees, and negatively in bonobos, and on average bonobos have higher scores on refusal. These interspecies differences in maternal style are discussed in the light of interspecies differences in infant development, infant vulnerability to aggression, interbirth intervals, and female sociality.

Mother-Infant Interactions in Slow Lorises (Nycticebus bengalensis) and Pygmy Lorises (Nycticebus pygmaeus)

The study had three purposes: (1) to obtain information about mother-infant interactions in a rarely studied nocturnal prosimian, the pygmy loris (Nycticebus pygmaeus); (2) to compare pygmy lorises with a closely related and better-studied nocturnal prosimian, the Bengal slow loris (Nycticebus bengalensis); and (3) to determine how the presence of a second offspring affected mother-infant interactions in pygmy lorises. Three Bengal slow loris mothers and 3 pygmy loris mothers served as subjects, along with their 10 offspring (4 Bengal slow loris singletons, 2 pygmy loris singletons and 2 sets of pygmy loris twins). Observations were carried out in a zoo research facility for the first 24 weeks of the infants’ lives. Although the two species differ in size and reproductive patterns, mother-infant interactions were similar. The primary modes of infant and adult contact were ventral and passive contact, respectively. Mothers parked their infants from the first week, and infants followed from the second week. Mothers displayed little protection or rejection, and there was little aggression. Infants solicited play and social grooming from their mothers. Pygmy loris mothers engaged in social grooming and play with their infants more frequently and for longer periods if the infant was a singleton rather than a twin.

Evidence from urinary cortisol that maternal behavior is related to stress in gorillas 1

BAHR, N.I., C. R. P. PRYCE, M. DÖBELI AND R.D. MARTIN. Evidence from urinary cortisol that maternal behavior is related to stress in gorillas. PHYSIOL BEHAV 64(4) 429–437, 1998.—By studying western lowland gorillas ( Gorilla gorilla gorilla, n = 8) in zoological gardens via ethological and non-invasive physiological techniques, we have demonstrated that their postpartum maternal behavior is related negatively to their postpartum urinary titers of cortisol. On the basis of this finding, it is proposed that postpartum stress contributes to disrupted maternal behavior in the gorilla in captivity. Morning urine samples were collected with a mean sampling interval of 1.6 days from Day 14 prepartum to Day 14 postpartum ( n = 11 pregnancies). Creatinine-indexed (Cr) urinary cortisol titers declined significantly between Day 9 to 1 prepartum (0.634 ± 0.014 μg/mg of Cr, mean ± SEM) and Day 1 to 6 postpartum (0.396 ± 0.030 μg/mg of Cr, mean ± SEM; p < 0.01–0.001). For each pregnancy, the relative postpartum decline in urinary cortisol was calculated as (μg of cortisol/mg of Cr Day 1 to 4)/(μg of cortisol/mg of Cr Day −4 to -1). Values ranged from 0.35 to 1.12, were independent of absolute prepartum cortisol titers, and were interpreted as evidence of inter-female differences in postpartum hypothalamo–pituitary–adrenal axis activity and, therefore, postpartum stress. This postpartum stress index was negatively correlated with the amount of time (0–100%) that females carried and supported their 0–14 day-old infants in a ventral position during locomotion ( r s = −0.68, p < 0.05) and tended to be negatively correlated with the total amount of time (0–100%) they spent in ventro–ventral contact with their infants ( r s = −0.58; p < 0.10). This study provides the first physiological evidence that postpartum stress is an important etiologic factor in gorilla maternal failure in captive environments.

The mating behaviour of the earthwormLumbricus terrestris(Oligochaeta: Lumbricidae)

A field observation suggested that the mating of the earthwormLumbricus terrestrisL. might involve a pre‐copulation behaviour sequence during which prospective partners visit each other's burrows. This was studied in laboratory investigations, where pairs of Finnish, field collectedL. terrestriswere observed directly and behaviour of groups of four or nine previously unmatedL. terrestrisof English origin was studied by video‐recording. In total, 15 full mating sequences were recorded. Mate searching involved trail‐following on the soil surface. This was followed by a series of, usually reciprocated, burrow visits. The number of visits by an individual worm showed a high degree of variability (n= 1–17). A burrow visit typically consisted of anterior segments insertion, for a period of 30 to 50 seconds, but also deeper burrow‐penetrations, which sometimes lasted several minutes, were recorded. Resident worms, when visited, either withdrew below ground completely or remained at the surface, with the first few anterior segments in view. Visiting worms normally retained their posterior segments in their own burrows. Visits were fewer when burrow openings were more widely separated. Partners often maintained close contact while moving back and forth between the burrow openings and the pre‐copulation phase appeared as specific courtship behaviour. Uninterrupted, the precopulation behaviour sequences lasted from 11 to 22 minutes in video‐taped matings and approximately 90 minutes in the single directly‐observed mating. After a pre‐copulation sequence, pairs adopted a static ‘s’‐shaped copulation position of close ventral contact, during which both individuals bent their anterior segments away from the partner's body. Copulations lasted from 69 to 200 minutes (median length for video‐taped matings 135 minutes). Other individuals often touched the copulating pair. Where this occurred, matings were shorter compared to those with no interference. We present a scheme for the mating ofL. terrestris, discuss its different phases and propose a few lines for further studies.

Maternal Condition and the Quality of Maternal Care in Vervet Monkeys

Seemingly contradictory results on the relationship between maternal condition and the quality of maternal care can be resolved by the hypothesis that maternal rejection is a U-shaped function of maternal condition. Data from 160 vervet monkey (Cercopithecus aethiops sabaeus) mother-infant dyads living in captive social groups were used to evaluate the influence of maternal reproductive condition on mothcr-infant contact, maternal rejection and infant mortality. Reproductive condition was defined as Marginal, Prime and Average based on age, weight, and dominance rank. Marginal mothers were at the extremes of the reproductive age distribution (3 years old or over 14) or were below a critical body weight (3.9 kg), characteristics that are associated with low rates of fertility in the study population. Prime mothers were in the top third of the female dominance hierarchy and of prime age (5-13), characteristics associated with higher than average fertility. Both marginal mothers and prime mothers had similar high rates of maternal rejection and low rates of ventral contact and proximity with their infants. Compared to mothers in the two extreme groups, mothers in average reproductive condition were significantly less rejecting and played a larger role in maintaining contact with their infants. Rates of maternal rejection, mother-infant contact, responsibility for contact, and the percentage time that infants spent on nonmaternal caretakers were all significantly related to maternal condition in U-shaped or inverted U-shaped functions. The infant mortality due to maternal abandonment or neglect was highest in the marginal group and was related to low body weight of the mother. We conclude that mothers in marginal condition limited maternal care to restore their own health, often at the expense of infant mortality, whereas mothers in prime condition used rejection to shorten the interval to the ncxt conception, without suffering higher rates of infant mortality than average mothers.

Somatosensory control of the onset and retention of maternal responsiveness in primiparous Sprague-Dawley rats

The role of perioral and ventral-trunk somatosensory stimulation from pups mediating the initial expression of maternal behavior and its long-term retention 8 days later, was investigated. Six groups of female rats were permitted to physically interact with four 1–5-day-old foster pups for 1 h, 36 h after Cesarean delivery on gestation day 21. Prior to this maternal experience, dams were subjected to: reduced cutaneous rostral snout sensitivity (anaptia) by injection of lidocaine into the mystacial pads; reduced ventral-trunk sensations by occlusion of the entire ventrum with a full spandex jacket; both manipulations; or control manipulations. Additional groups of females not receiving a maternal experience (inexperienced) also received the somatosensory deprivation or control manipulations. During retention testing, rats in the singly manipulated experienced groups exhibited reduced latencies to become maternal in comparison to their inexperienced counterparts (approximately 3 days vs. 8 days). However, rats previously rendered both anaptic and ventrally-occluded responded like inexperienced rats in showing a long latency to become maternal (8 days). Thus, reduction of either perioral or ventral somatosensory contact from pups did not block the maternal experience effect, but reduction of both of these inputs did.

Behavior of nursery/peer-reared and mother-reared rhesus monkeys from birth through 2 years of age

The behavior of 8 nursery/peer-reared and 16 mother-only reared rhesus macaques was observed between birth and 5 months of age, with follow-up studies conducted when the animals were 10–21 months old and living in large social groups. Nursery-reared neonates were more awake, active, and irritable than mother-only reared monkeys. From 1 to 5 months of age the nursery/peer-reared animals exhibited a greater variety of behaviors than the mother-only reared infants, which spent the majority of the time in ventral contact with mothers. As juveniles the groups were indistinguishable with the exception of more self-directed behaviors observed in the nursery/peer-reared monkeys. Both rearing conditions, by virtue of their atypicality, imposed restrictions on social development. The behavioral similarity of the juveniles while in the large social group may be a function of maturation or due to the rehabilitative effect of the large social group.

Proteolytic activity of specialized surface protrusions formed at rosette contact sites of transformed cells

Surface protrusions at the leading edge of a moving cell that make contact with the surrounding extracellular matrix (ECM) are its main motor for locomotion and invasion. Chicken embryonic fibroblasts transformed by Rous sarcoma virus (RSV-CEF) form specialized membrane rosette-shaped contact sites on planar substrata as shown by interference reflection microscopy (IRM). Such activity is lacking in normal cells. These rosette contacts are more labile than other adhesion sites, such as focal and close contacts. Ultrastructural studies demonstrate that rosettes are sites at which membrane protrusions from the ventral cell surface contact the substratum. These protrusions are filled with meshworks of microfilaments and contain the pp60src oncogene product, actin, vinculin, and alpha-actinin. However, unlike focal contacts, at the rosettes these proteins interact to extend a highly motile membrane. Rosettes have the biological activity of degrading ECM components, as demonstrated by (1) local degradation of fibronectin substrata at sites of rosette contacts, but not focal and close contacts; (2) localization of putative antiprotease antibody at sites of rosette contacts, but not at focal an close contacts; and (3) local disruption of fibronectin matrix at sites of protrusive activity seen by transmission electron microscopy (TEM). In addition, formation of the rosette contact is insensitive to the ionophore monensin, and to inhibitors of proteolytic enzymes, while local fibronectin degradation at rosette contacts is inhibited by inhibitors of metalloproteases, 1,10-phenanthroline and NP-20. I consider these membrane protrusions of the rosette contacts in RSV-transformed cells specialized structural entities--invadopodia--that are involved in the local degradation of the ECM.

Differences between the sensory organs of phytal and bottom-dwelling &amp;lt;i&amp;gt;Loxoconcha&amp;lt;/i&amp;gt; (Ostracoda, Crustacea)

Abstract. The morphology and distribution patterns of pores with a bristle were studied on two Loxoconcha species living in adjacent but different habitats: the phytal species L. japonica and the bottom-dwelling species L. uranouchiensis. Both species have only one kind of pore – sieve-pore – from which either of two kinds of bristles emerges. The two types of bristles are here called the “smooth”– and the “twisted”–type according to their morphological features. The sieve-pore orifice of the phytal Loxoconcha remains completely open, whereas that of the bottom-dwelling species has a special morphology both in the sieve-plate and the basal part of the bristle to cope with the adhesion of dirt. The number and distribution pattern of “twisted”-type bristles (chemo-receptors?) are the same in both species. The “smooth”-type bristles (mechano-receptors?), however, are distributed more densely in the ventral area of the bottom-dwelling species compared with those of the phytal species. This difference seems to be related to the mode of life, specifically the difference in the manner of ventral contact with substrata. Some adaptive characters of ostracod pores are clarified and their significance to ostracod taxonomy and palaeocology is discussed.

Mother-infant interactions in captive slow lorises (Nycticebus coucang).

Information is presented about mother-infant interactions and infant development in a rarely studied prosimian primate, the slow loris (Nycticebus coucang). Four dyads were observed, by means of closed circuit TV, in a semi-natural environment for 1 hour per day three times a week. Infants were inactive for the first 6-8 weeks. Although mothers carried infants, they also left them alone for substantial periods of time after the 1st week. Over the 20-week study period, there was a significant decline in ventral contact but not in sitting within 12 inches or engaging in active social interactions. By the end of the study, infants were not yet fully independent. Three of the 4 were primarily responsible for maintaining physical closeness to the mother; they made most of the approaches and mothers made most of the departures. However, only 2 of the 4 infants had assumed responsibility for the initiation and maintenance of social interactions with the mother. By comparison with other nocturnal prosimians of similar size, the rate of development is relatively slow. Unlike many anthropoids, mothers were not strongly protective or rejecting. They did not bring infants back to a fixed location or try to prevent infants from leaving them; and the decline in ventral contact was not accompanied by fights between the pair. The 3 group-living mothers were more protective than the single individually housed mother, and it would seem advisable to isolate mother-infant pairs in laboratory breeding colonies.

Motor neuronal receptive fields delimit patterns of motor activity during locomotion of the locust

During walking, the muscles of a leg undergo a typical sequence of activity, which is partly shaped by phasic sensory feedback. To assess the role played by such feedback, we characterized intracellularly the receptive fields of tarsal motor neurons in the locust Schistocerca gregaria and considered these receptive fields within the context of a step cycle. The depressor motor neurons, active during the stance phase, are excited by ventral tarsal contact or an imposed levation and are inhibited by dorsal contact or an imposed depression. Partial deafferentation of the anterior tarsus reduces this stance phase depressor activity. The levator motor neuron, active during the swing phase, has the opposite receptive field. The retractor unguis motor neurons, synergistic to the depressors, are, like them, excited by ventral contact but, like the levator, are inhibited by afferents which can signal the end of the stance phase. The inhibition of the retractors could constitute a preparation for the swing phase, by reducing the grip on the substrate. The motor neuronal receptive fields thus appear to support the patterns of muscular activity recorded during walking. Excitation of the motor neurons by extero- and proprioceptors is usually direct: hair, canal, campaniform, and chordotonal afferents all evoke 1:1 EPSPs in motor neurons after a central latency of 1-1.5 msec. Inhibition is indirect, as IPSPs occur at least 2 msec later than the EPSPs. The motor neurons of one pool have overlapping but not necessarily identical, receptive fields. Parallel, supplementary excitatory and inhibitory pathways involving nonspiking local interneurons also exist, which can allow gain control of a specific reflex. The weight given to a reflex response will thus depend, first, on the number of motor neurons in a pool affected by the stimulus and, second, on the existence and state of intercalated interneurons.

Mating season effects on mother-infant conflict in Japanese macaques, Macaca fuscata

The impact of seasonal mating on the mother-infant relationship during the first year of the infant's life was documented in a confined troop of Japanese macaques. During the weeks in which the mothers were being mounted, negative behaviour directed towards the infants increased. As maternal rejections and punishments escalated, the infants displayed regressive behaviour (showing signs of distress more frequently). Infants also groomed their mothers at an increased rate at this time. Behaviour that indicated increased independence did not show increases during this time. Moreover, behaviour negatively associated with independence, such as ventral contact and proximity to the mother, remained stable throughout this time period. The mother-infant relationship undergoes a period of conflict during the mating season not because the mother is weaning her infant, but because it is to her reproductive advantage to regulate the times in which the infant is allowed to suckle.

Mother-infant behavior in vervet monkeys

Mother-infant behavior of 9 vervet monkey mothers who had failed in their last pregnancy were compared to the behavior of 14 mothers who had been successful in the prior year and to 11 primiparous mothers. The results indicated that females responded to the loss of one infant by increasing their level of care for their next infant. Females who had failed in their last pregnancy encouraged ventral contact and were more restrictive of their infant's movements, they gave more care and attention to their infants, and they played a greater part in keeping their infants near, compared to mothers who had been successful in their last pregnancy. Mothers who had failed in their last pregnancy were also more attentive and protective toward their infants than primiparous mothers who had had no prior reproductive experience. The increase in maternal care by females who had failed in their last pregnancy was accompanied by an increase in the interval to the birth of their next infant. These differences could not be completely explained by differences in the mothers' age or in the presence of other immature offspring. They suggest that vervet mothers can adjust their level of parental care based on the quality of their past experience, and that these adjustments have an effect on the mother's future reproductive potential.

Infant-directed behavior of rhesus monkeys during their first pregnancy and parturition.

To determine whether pregnancy influences the response of rhesus monkeys towards infants, 11 females were observed during 15-min exposures to a 1- to 15-day-old infant at 1- to 2-week intervals throughout pregnancy. No evidence was found for increasing willingness to contact infants as pregnancy progressed. The parturition of 5 of these females was observed, which included 1 live breech birth. These primiparae all established ventral contact with their infants at birth, though most of them appeared to passively allow the infant to initiate contact while their own attention was directed at licking the birth fluids.

A variable-temperature surrogate mother for studying attachment in infant monkeys

A variable temperature surrogate mother for use with infant monkeys is described. The apparatus is designed to facilitate manipulation of the infant-surrogate attachment bond. Data showing significant behavioral changes in ventral contact and locomotion as a function of depressed surrogate temperature are presented. The value of this technique in the production of psyehopathology is indicated by a dramatic and progressive increase in disturbance behaviors during a 9-week test period. Implications for the use of a variable temperature surrogate in studying animal models of psyehopathology are noted.

Effects of group environment on the mother-infant relationship in pigtailed monkeys (Macaca nemestrina)

Behavior of sixMacaca nemestrina mother-infant pairs was observed in two different environments; three pairs were part of a large group in a compound and three pairs were housed in individual laboratory cages. At weeks 14–15 of the infants' lives, group mothers were more retentive of their infants than caged mothers; group infants spent more time in ventral contact with mother and nursed more than did caged infants. The authors conclude that the greater dependence of an infant raised in a potentially dangerous group setting is due to a more protective mother rather than to a more fearful infant.

The influence of light and touch on the orientation and behaviour of Gonodactylus glabrous Brooks

The experiments on the reactions of Gonodactylus glabrous to light and to touching objects show that: 1. It swims towards dark objects even if thereby it has to swim towards the light (skototaxis). 2. Darker objects are preferred to lighter objects. 3. Bigger objects are preferred to smaller objects. 4. In perpendicular light it exhibits a dorsal light compass reaction. 5. It comes to rest when it has many ventral and lateral contact points (low thigmokinesis). 6. It is more active and willing to leave its hiding place in darkness than in light. 7. There is a characteristic compromise in the reaction when light and touch are combined as stimuli acting on the animal in different directions. 8. Light and touch are two stimuli which trap the Gonodactylus under stones and under other objects during the day. When the intensity of light falls to a minimum during the night the animals become less bound to their hiding places and are able to leave their shelter and swim about.