On the distribution of Triturus vittatus ophryticus in Northern Anatolia

Abstract

On a reed-stem, collected in April 1992 in Lake Köycegiz (SW Turkey), numerous gemmules of Spongilla alba were found on and between the tubes of the marine polychaete Ficopomatus enigmaticus.     

Female Sexual Interference in the Smooth Newt,Triturus vulgaris vulgaris

Competition between unmated females for males was observed in the smooth newt, T. vulgaris, during the early part of the breeding season. Females interfered at the spermatophore-transfer stage of courtship, preventing a rival female from picking up the sperm mass. Interference often resulted in the rival female abandoning the courtship encounter. In many of the encounters (70%), the interfering female was inseminated. However, interference between females was not observed after the commencement of ovulation. By contrast, the incidence of sexual interference between males was low during the preovulatory period and increased significantly post-ovulation. Sexual interference in newts and salamanders has previously only been observed between males. During the greater part of the breeding season, when females are ovipositing, eggs are the limiting resource and males compete for access to receptive females. However, this study suggests that early in the breeding season, prior to commencement of ovulation, the limiting resource may temporarily be sperm, due to the physiological constraint of spermatophore production. This may lead to female competition for mates.     

Sexual Interference and Sexual Defense in the Smooth Newt,Triturus vulgaris (Amphibia,Urodela, Salamandridae)

• 1 When a male smooth newt encounters a ♀ who is already engaged in courtship, he may mimic her behaviour during the spermatophore deposition and transfer stages of the courtship. He thereby usurps the courting ♂ and may inseminate the ♀ himself. Such sexual interference depresses the short-term, and perhaps long-term, mating success of the courting ♂.
• 2 In the presence of a potential rival, the courting ♂ alters certain aspects of his sexual behaviour. He displays more intensely to the ♀ and attempts to draw her away from the rival by increasing the duration of his display. He may also “check” that it is the ♀, and not the rival, who will elicit the deposition of a spermatophore from him. These changes in the behaviour of the courting ♂ are interpreted as defense against sexual interference.
• 3 Female smooth newts may be multiply inseminated as a consequence of sexual interference; this may result in sperm competition. However, ♀♀ seem to find competitive interactions between ♂ ♂ “aversive”.
• 4 Sexual interference by ♀-mimicry and associated defensive behaviour patterns are common in the urodele amphibians. Interference can be thought of as a “side-payment” conditional mating strategy.

     

The Sexual Behaviour of the Great Crested Newt,Triturus cristatus (Amphibia: Salamandridae)

The sexual behaviour of Triturus cristatus is described. The first stage of sexual behaviour consists of an orientation phase in which the male approaches the female, sniffs her and moves in front of and perpendicular to her. The second stage is a prolonged period of static display with two different tail movements, called Fan and Lash, in 13.8 ± 1.3 bouts (x? ± SE) with intervals of 10.5 ± 0.3 s between bouts. Each bout contains 6.7 ± 0.3 regular Fan beats at a frequency of 0.5–0.8 Hz. This Fanning provides olfactory and mechanical stimulation to the female. 15% of bouts also contain a violent Lash, in which the male rapidly slaps the female's flank. Some Lashes are used to stop the female when she tries to move away. In the third stage of the sexual sequence, the male turns away, Creeps for 6.7 ± 0.3 s (x? ± SE) and then Quivers his tail. A receptive female follows and touches his tail, and the male deposits a spermatophore and then turns to one side with his tail folded along his flank in a position called Brake. The female now approaches again and the male steps away sideways in a movement called Rebrake. After several Rebrakes the male stops, the female touches his tail and the spermatophore may now be picked up in her cloaca. This sequence can be repeated several times during one encounter. This behaviour is discussed in relation to previous studies of courtship in this genus.     

潮汕蝾螈的求偶行为

潮汕蝾螈(Cynops orphicus)是我国特有的濒危有尾两栖类,繁殖季节始于5月中旬。对其求偶行为观察发现,该螈求偶模式表现出与东方蝾螈(C.orientalis)相似的特点,但雄性扇尾和潜行时间(25~37 s)较东方蝾螈(10~20 s)更长;雄性在一次求偶中多次排精,雌性亦可多次纳精,精子囊形态与东方蝾螈类同;雌性纳精后,雄性反转咬住其腹部,被咬雌性呈现植物态。纳精过后,雌性出现暂时的冷漠或恐惧,不再接受雄性求偶。该螈成功纳精在累次求偶行为中占比不高(2.7%),但较东方蝾螈(1.1%)成功率高。雄性之间存在求偶过程中的竞争和干扰行为。     

Cumulative Effect of Male's Displays in the Sexual Behaviour of the Smooth Newt Triturus vulgaris (Urodela,Salamandridae)1

The relevance of the temporal spacing of signals to the timing and nature of the receiver's response during a communicative process was studied in the sexual behaviour of the smooth newt Triturus vulgaris. The possibility that a high rate of stimulation allows an accumulation of the effects of successive signals was investigated by comparing sexual interactions leading and not leading to spermatophore deposition. Results showed that the difference between the two types of interactions lay only in temporal features of the stimulation provided by the male to the female. Females, although in a comparable initial state of receptivity and exposed to comparable amounts of stimulation, performed the act triggering spermatophore deposition by the male only in some interactions. Display bouts, in which the male displayed at short intervals (less than 4 s), were longer in interactions where spermatophore deposition took place than in the others. This suggests that courtship was effective if accumulation of the effects of male displays could occur. This proposition was supported by the observation of a progressive change in the immediate female response to a given male display in the group where courtship bouts were longer. Our results indicate the existence of a system of tonic communication (see Schleidt 1973) during the sexual behaviour of the smooth newt, in which the effects of the male displays accumulate over time until some critical threshold is reached in the female.     

Sexual Size Dimorphism,Canine Dimorphism,and Male-Male Competition in Primates

Sexual size dimorphism is generally associated with sexual selection via agonistic male competition in nonhuman primates. These primate models play an important role in understanding the origins and evolution of human behavior. Human size dimorphism is often hypothesized to be associated with high rates of male violence and polygyny. This raises the question of whether human dimorphism and patterns of male violence are inherited from a common ancestor with chimpanzees or are uniquely derived. Here I review patterns of, and causal models for, dimorphism in humans and other primates. While dimorphism in primates is associated with agonistic male mate competition, a variety of factors can affect male and female size, and thereby dimorphism. The causes of human sexual size dimorphism are uncertain, and could involve several non-mutually-exclusive mechanisms, such as mate competition, resource competition, intergroup violence, and female choice. A phylogenetic reconstruction of the evolution of dimorphism, including fossil hominins, indicates that the modern human condition is derived. This suggests that at least some behavioral similarities with Pan associated with dimorphism may have arisen independently, and not directly from a common ancestor.     

Ultrastructure of the Respiratory Epithelium in the Lungs of the Newt Triturus cristatus

The respiratory epithelium in the lungs of the newt Triturus cristatus has been studied by electron microscopy. The entire pulmonary gas-exchange area is covered by a continuous epithelium, the cells of which are all of the same type and are termed “pneumonocytes”. Typically each pneumonocyte is squamous and has attenuated sheets of cytoplasm which cover the pulmonary capillaries. Its free surface bears microvilli while mitochondria, multivesticular bodies and small inclusions are prominent in its cytoplasm. Many pneuomonocytes send cytoplasmic processes deep into the substance of the lung wall. It is postulated that these processes may help to anchor the epithelium.     

Hormonal Induction of Male Courtship Behavior in the Japanese Newt, Cynops pyrrhogaster

In the breeding season, the sexually mature male newt, Cynops pyrrhogaster, vibrates the tail in front of the female at an early stage of courtship. Effects of prolactin (PRL), gonadotropin (GTH), and sex steroids on this behavior were investigated in the male paired with the female receiving PRL and GTH. The behavior was elicited in the sexually inert male by injections of PRL of bovine, ovine, or bullfrog origin and human chorionic gonadotropin or bullfrog LH and FSH in combination. The effect of PRL or GTH alone was less marked than that of PRL plus GTH, especially in terms of frequency of the behavior. In the hypophysectomized male, combination of PRL and GTH significantly increased both the incidence and frequency of the behavior. However, PRL alone was not effective, and the effect of GTH alone was less pronounced than that in the intact animal receiving GTH injections. The effect of GTH was nullified by castration. In the PRL-treated castrated animal, testosterone or dihydrotestosterone, but not estradiol, was effective in inducing the behavior.     

Courtship Display in a Natural Population of Crested Newts,Triturus cristatus

Field observations of courtship displays in a natural population of crested newts, Triturus cristatus, are described. Males were observed both courting females and displaying to other males, and male: male interactions were as frequent as courtships. Many courtships were also interrupted by intruding males, and courtship success was less than 7%. A comparison is made with aquaria studies, which shows that the presence of more individuals in the field, where newts aggregate in leks when breeding, is influencing male behaviour. On the other hand, the different features of the displays observed in the field did not differ to any major extent from behaviour patterns observed in aquaria studies.     

The juxtaglomerular apparatus in the mesonephros of Newt (Triturus cristatus)

Summary 1)As in mammals, the juxtaglomerular apparatus of the Newt (Triturus cristatus) is composed by cells of the media of the afferent glomerular arteriole and by cells of the intermediary tubule. 2) The cells of the media of the glomerular arteriole are of two different types: granular and agranular cells. 3) The intermediary tubule is formed by dark and light cells. 4) Part of interrenal body is located close to glomerular arteriole and intermediary tubule.This work was supported by grant of Consiglio Nazionale delle Ricerche of Italy (C.N.R.) N. 115/815/04677.     

大蹼铃蟾的两性异形

2018年6—8月,测量采自云南省昆明市金殿水库后山的71只(47♂,24♀)大蹼铃蟾Bombina maxima成体的体长、头长、头宽等15项形态特征指标并检验该物种的两性异形。结果表明:雄性平均体长为53.54 mm±1.14 mm,雌性平均体长为52.74 mm±1.45 mm,雄性与雌性平均体长比为1.015,两性异性指数为0.01;大蹼铃蟾的体长、体质量与性别之间的差异无统计学意义;除了雌性的眼间距外,其余13项形态特征与体长均有极显著相关性;以体长为协变量的协方差分析结果显示,大蹼铃蟾的头长、吻长、前臂宽、腿或后肢全长、胫长、胫宽和跗足长在两性间的差异有高度统计学意义;雄性的这7项形态特征随体长的生长速率大于雌性。性选择假说能解释大蹼铃蟾的两性异形现象。     

旱地沙蜥的两性异形

旱地沙蜥Phrynocephalus helioscopus是一种在我国仅分布于新疆北部的蜥蜴。通过测量和比较采自新疆塔城地区旱地沙蜥的体长、口宽、头宽、头高、头长、眼间距、腹部长、尾长等8个形态特征研究旱地沙蜥的两性异形。本研究共采集到旱地沙蜥51只,其中,雌性23只,雄性28只。雌雄平均体长分别为48.03 mm和47.69 mm。结果表明旱地沙蜥两性体长的差异无统计学意义,其体长与口宽、头宽、头高、头长、眼间距、腹部长和尾长7个形态特征均显著正相关。在控制体长的基础上比较得出,雌雄个体在头高、头长、腹部长和尾长上的差异有统计学意义,口宽、头宽、眼间距的差异无统计学意义。其中,雄性的头高、头长和尾长均大于雌性,雌性的腹部长则明显大于雄性。旱地沙蜥的腹部长呈现明显的异形生长,雌性的生长速率明显大于雄性。旱地沙蜥的两性异形可能是性选择压力与生育力选择压力共同作用的结果,雄性头部更大、尾部更长,在性选择中具有优势;雌性腹部更长,能够繁育更多的后代。     

康县隆肛蛙的两性异形

测量和比较了采自甘肃省康县的康县隆肛蛙Feirana kangxianensis标本共计90只(雌性48只,雄性42只)。结果表明,康县隆肛蛙成体的头体长、头长、头宽、吻长、鼻间距、眼间距、眼径、鼓膜长、前臂及手长、后肢全长、手长、足长的形态特征在两性间的差异有统计学意义。以头体长为协变量的协方差分析显示,康县隆肛蛙两性的差异均有统计学意义,异形指数达到0.08,雌性与雄性的平均头体长比值为1.091。对所有测量的形态特征与头体长进行一元线性回归分析表明,雌性康县隆肛蛙局部形态特征的生长速度明显大于雄性,其中,吻长、眼间距、眼径、鼓膜长、前臂及手长、手长的两性差异最明显。生育力选择假设能解释康县隆肛蛙的两性异形现象。     

Female Attraction to Conspecific Chemical Cues in the Palmate Newt Triturus helveticus

Although chemosignals are largely used in sexual communication in urodeles, olfactometer studies in newts provided contrasting results about the sex specificity of female behavioural responses. Because long‐range sexual advertisement is believed to be costly, some species might restrain this activity to close interactions with conspecifics. We tested chemical‐mediated sexual attraction in female palmate newt (Triturus helveticus) by measuring the attraction to male and female odours in a linear water olfactometer. Unexpectedly, females were attracted towards conspecifics regardless of sex. They did not show attraction towards Limnaea stagnalis, a common sympatric aquatic gastropod. These results do not support the use of long‐range male sexual signalling in the palmate newt. Instead, conspecific attraction is likely to promote aggregation of males and females in breeding ponds. Observations in the field and in the laboratory tend to support the aggregative behaviour of this species. We discuss the possible function of conspecific attraction in this context. Heading towards any conspecific would increase the probability of finding potential mates. Chemical cues do not need to be sex‐specific at that stage so that long‐range sexual advertisement might be unnecessary. This work emphasizes the need for studies investigating the evolutionary relationships between sexual signalling systems and population‐distribution patterns.     

One Species, Three Pleistocene Evolutionary Histories: Phylogeography of the Italian Crested Newt, Triturus carnifex

Phylogeographic patterns of temperate species from the Mediterranean peninsulas have been investigated intensively. Nevertheless, as more phylogeographies become available, either unique patterns or new lines of concordance continue to emerge, providing new insights on the evolution of regional biotas. Here, we investigated the phylogeography and evolutionary history of the Italian crested newt, Triturus carnifex, through phylogenetic, molecular dating and population structure analyses of two mitochondrial gene fragments (ND2 and ND4; overall 1273 bp). We found three main mtDNA lineages having parapatric distribution and estimated divergence times between Late Pliocene and Early Pleistocene. One lineage (S) was widespread south of the northern Apennine chain and was further geographically structured into five sublineages, likely of Middle Pleistocene origin. The second lineage (C) was widespread throughout the Padano-Venetian plain and did not show a clear phylogeographic structure. The third lineage (N) was observed in only two populations located on western Croatia/Slovenia. Results of analysis of molecular variance suggested that partitioning populations according to the geographic distribution of these lineages and sublineages explains 76% of the observed genetic variation. The phylogeographic structure observed within T. carnifex and divergence time estimates among its lineages, suggest that responses to Pleistocene environmental changes in this single species have been as diverse as those found previously among several codistributed temperate species combined. Consistent with the landscape heterogeneity, physiographic features, and palaeogeographical evolution of its distribution range, these responses encompass multiple refugia along the Apennine chain, lowland refugia in large peri-coastal plains, and a 'cryptic' northern refugium.     

The Dilemma of Choosing a Reference Character for Measuring Sexual Size Dimorphism,Sexual Body Component Dimorphism,and Character Scaling: Cryptic Dimorphism and Allometry in the Scorpion Hadrurus arizonensis

Sexual differences in morphology, ranging from subtle to extravagant, occur commonly in many animal species. These differences can encompass overall body size (sexual size dimorphism, SSD) or the size and/or shape of specific body parts (sexual body component dimorphism, SBCD). Interacting forces of natural and sexual selection shape much of the expression of dimorphism we see, though non-adaptive processes may be involved. Differential scaling of individual features can result when selection favors either exaggerated (positive allometry) or reduced (negative allometry) size during growth. Studies of sexual dimorphism and character scaling rely on multivariate models that ideally use an unbiased reference character as an overall measure of body size. We explored several candidate reference characters in a cryptically dimorphic taxon, Hadrurus arizonensis. In this scorpion, essentially every body component among the 16 we examined could be interpreted as dimorphic, but identification of SSD and SBCD depended on which character was used as the reference (prosoma length, prosoma area, total length, principal component 1, or metasoma segment 1 width). Of these characters, discriminant function analysis suggested that metasoma segment 1 width was the most appropriate. The pattern of dimorphism in H. arizonensis mirrored that seen in other more obviously dimorphic scorpions, with static allometry trending towards isometry in most characters. Our findings are consistent with the conclusions of others that fecundity selection likely favors a larger prosoma in female scorpions, whereas sexual selection may favor other body parts being larger in males, especially the metasoma, pectines, and possibly the chela. For this scorpion and probably most other organisms, the choice of reference character profoundly affects interpretations of SSD, SBCD, and allometry. Thus, researchers need to broaden their consideration of an appropriate reference and exercise caution in interpreting findings. We highly recommend use of discriminant function analysis to identify the least-biased reference character.