Zoology最新文献 - Book学术

Cytogenetic insights into Sosippinae (Araneae, Lycosidae) reveal pronounced diploid number reduction in Aglaoctenus and elevated number of rDNA loci in two unrelated species

IF 1.6 3区生物学 Q2 ZOOLOGY

Zoology

Pub Date : 2025-04-16 DOI: 10.1016/j.zool.2025.126269

Mariana Bessa Sanches , Lucas Henrique Bonfim Souza , Bruno Cansanção Silva , Conrado Mario da Rosa , Antonio Domingos Brescovit , Luciana Bolsoni Lourenço , Douglas Araujo

Spiders represent a fascinating group for studying chromosomal evolution due to their dynamic karyotypes, which reveal significant differences even between closely related taxa. Lycosidae, one of the most species-rich families of spiders, has its major relationships well stablished, though minor interspecific relationships remain poorly understood. Here, we analyzed chromosomal data from four species belonging to Aglaoctenus and Diapontia, two genera within the subfamily Sosippinae, to discuss the evolution of chromosomal traits within this lineage. For karyological analysis, we employed Giemsa staining, C-banding, Ag-NOR staining, and 28S rDNA FISH to identify key chromosomal characteristics and the distribution of repetitive elements. Both A. oblongus and D. uruguayensis exhibited 2n♂=28, X₁X₂, with acro/telocentric morphology, hypothesized to represent the ancestral condition for Lycosoidea. However, regarding the 28S rDNA chromosome mapping, these species revealed an unusually high number of loci with eight chromosome clusters in A. oblongus and a polymorphic condition in D. uruguayensis (10–14 signals), underscoring the utility of additional techniques for detecting specific chromosomal regions. Interestingly, A. castaneus and A. lagotis displayed a more derived karyotype, characterized by 2 n♂= 14, X₁X₂ and acro/telocentric morphology, with the sex chromosomes (X₁ and X₂) smaller than the autosomes. Taken together, these data suggest that, following the diversification of Aglaoctenus, a significant reduction in diploid number occurred, affecting only the autosomes. These findings encourage further cytogenetic research within Sosippinae and support the use of these data in future phylogenetic studies.

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引用次数: 0

Back to the water II: Variation in eye and cranial morphology in Telmatobius frogs with different lifestyles

IF 1.6 3区生物学 Q2 ZOOLOGY

Zoology

Pub Date : 2025-04-16 DOI: 10.1016/j.zool.2025.126267

J. Sebastián Barrionuevo

Several tetrapod lineages have independently evolved an aquatic lifestyle, driving structural and functional modifications. Changes in eye size and position are key trends in this transition. While most frogs and toads have aquatic larvae, the majority of adults are terrestrial. In contrast, Telmatobius frogs exhibit a unique spectrum from semiaquatic to strictly aquatic lifestyles, linked to the colonization of the Andean highlands. This study examines variation in eye size, position, and cranial proportions, in two species: the semi-aquatic Telmatobius oxycephalus and the strictly aquatic T. rubigo. Measurements across post-metamorphic stages were used to compare groups and assess allometric patterns. Telmatobius rubigo, which inhabits high altitudes, has smaller eyes and a more dorsal/frontal eye position than T. oxycephalus. Among T. oxycephalus, the forest population at lower elevations has larger eyes compared to valley counterparts at intermediate altitudes. Cranial analysis reveals that T. rubigo has smaller orbits and larger otic capsules, while T. oxycephalus shows the opposite pattern. These findings suggest that smaller eye size and more frontal/dorsal positioning evolved in response to the aquatic lifestyle at high elevations. This pattern parallels that of highly aquatic pipid frogs, which adapted to aquatic habitats during the Cretaceous. In contrast, Telmatobius specialization for aquatic environments is relatively recent and associated with Andean colonization, providing a unique opportunity to study an adaptive radiation within a modern evolutionary context.

{"title":"Back to the water II: Variation in eye and cranial morphology in Telmatobius frogs with different lifestyles","authors":"J. Sebastián Barrionuevo","doi":"10.1016/j.zool.2025.126267","DOIUrl":"10.1016/j.zool.2025.126267","url":null,"abstract":"<div><div>Several tetrapod lineages have independently evolved an aquatic lifestyle, driving structural and functional modifications. Changes in eye size and position are key trends in this transition. While most frogs and toads have aquatic larvae, the majority of adults are terrestrial. In contrast, <em>Telmatobius</em> frogs exhibit a unique spectrum from semiaquatic to strictly aquatic lifestyles, linked to the colonization of the Andean highlands. This study examines variation in eye size, position, and cranial proportions, in two species: the semi-aquatic <em>Telmatobius oxycephalus</em> and the strictly aquatic <em>T. rubigo</em>. Measurements across post-metamorphic stages were used to compare groups and assess allometric patterns. <em>Telmatobius rubigo</em>, which inhabits high altitudes, has smaller eyes and a more dorsal/frontal eye position than <em>T. oxycephalus</em>. Among <em>T. oxycephalus</em>, the forest population at lower elevations has larger eyes compared to valley counterparts at intermediate altitudes. Cranial analysis reveals that <em>T. rubigo</em> has smaller orbits and larger otic capsules, while <em>T. oxycephalus</em> shows the opposite pattern. These findings suggest that smaller eye size and more frontal/dorsal positioning evolved in response to the aquatic lifestyle at high elevations. This pattern parallels that of highly aquatic pipid frogs, which adapted to aquatic habitats during the Cretaceous. In contrast, <em>Telmatobius</em> specialization for aquatic environments is relatively recent and associated with Andean colonization, providing a unique opportunity to study an adaptive radiation within a modern evolutionary context.</div></div>","PeriodicalId":49330,"journal":{"name":"Zoology","volume":"170 ","pages":"Article 126267"},"PeriodicalIF":1.6,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143874563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Impacts of competition on juveniles of two sympatric freshwater prawn species from Pampean ecosystems: Palaemon argentinus and Macrobrachium borellii

IF 1.6 3区生物学 Q2 ZOOLOGY

Zoology

Pub Date : 2025-04-16 DOI: 10.1016/j.zool.2025.126268

María Eugenia Scardamaglia, Karine Delevati Colpo

Competition is an interaction between individuals, either of the same species (intraspecific) or different species (interspecific), involving the contest for limited resources. This interaction can influence individual growth, reproduction, and survival, playing a critical role in regulating population dynamics and modulating community structures. In this study, we assessed the impact of competition type (intraspecific and interspecific) and competition pressure (low and high) on the coexistence of juvenile individuals of two sympatric prawn species commonly found in freshwater environments of South America: Palaemon argentinus and Macrobrachium borellii. To this end, we developed an experimental design to assess how different competition types and pressures affect the survival and growth rates of juveniles of both species, their frequency of use of the provided substrates and shelters, and their priority in obtaining food. The results showed that both the competition type and pressure influenced how these species coexist in experimental aquaria. High-pressure competition affected the survival of both species, with interspecific competition mainly impacting on the survival of P. argentinus and intraspecific competition mainly impacting on the survival of M. borellii. Macrobrachium borellii proved to be the dominant prawn because, under interspecific competition, this species showed higher survival rate, displaced P. argentinus from the spaces and substrates previously used, and secured food before P. argentinus when competitive pressure was high. However, the growth rate of both species was unaffected by either the competition type or pressure. This study provides insights into how competition can influence the ecological dynamics of these sympatric prawn species.

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引用次数: 0

Maternal and social status affect hair cortisol concentrations in brown bears

IF 1.6 3区生物学 Q2 ZOOLOGY

Zoology

Pub Date : 2025-03-01 DOI: 10.1016/j.zool.2025.126257

Marcello Franchini , Ashlee J. Mikkelsen , Agnieszka Sergiel , Nuria Selva , David M. Janz , Jonas Kindberg , Andreas Zedrosser

Hair cortisol concentration is affected by different biological factors, including age, sex, and reproductive status, and can provide important insights into fitness. Using cortisol concentrations of wild Scandinavian brown bears, Ursus arctos, the purpose of this study was to investigate cortisol variations among individuals in relation to age, sex, and reproductive status (solitary individuals vs individuals in a family group). Cortisol concentrations were measured in 448 hair samples of 303 brown bears (162 males and 141 females, from one to nine years of age) captured from 1990 to 2016. We found that members of family groups, i.e., mothers as well as their dependent offspring, had significantly higher cortisol concentrations compared to solitary individuals (males or females). Higher energetic costs in family groups are likely linked to growth of the offspring as well as maternal costs incurred by the rearing of offspring. Our findings provide valuable insights into the physiological effects of maternal care and reproductive status in mammals.

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引用次数: 0

To the roots: reconstruction of the ancestral state of the dorid feeding apparatus

IF 1.6 3区生物学 Q2 ZOOLOGY

Zoology

Pub Date : 2025-03-01 DOI: 10.1016/j.zool.2025.126256

Anna L. Mikhlina , Irina A. Ekimova , Dimitry M. Schepetov , Ángel Valdés , Elena V. Vortsepneva

Diet-driven ecological radiation has been proposed as a key factor in the diversification of Nudibranchia. Members of Doridina, one of the two major clades of nudibranchs, have a remarkably wide range of dietary preferences. The morphology of the feeding apparatus is related to prey preferences and feeding mechanisms. Therefore, the investigation of the evolutionary changes in the morphology of the feeding apparatus can provide valuable insights into the evolution of Doridina. Recent significant changes in our understanding of the phylogeny of Doridina have highlighted the need to re-evaluate current hypotheses on the evolution of the buccal armature morphology and correlated dietary shifts in this group. To address this, we compiled and analysed a comprehensive dataset that combined phylogenetic and morphological data to reconstruct the evolution of the buccal armature in Doridina. We also review the feeding biology of various groups of dorids to provide a deeper view of the evolution of the morphology of the feeding apparatus. We hypothesised the plesiomorphic conditions of the buccal armature for each large clade of Doridina and for the entire group. Within Doridina, there is a strong phylogenetic correlation with prey preference as major changes in the diet preferences of several clades led to significant transformations in radular morphology. We also discovered several cases of retention of plesiomorphic radular morphology and feeding mechanisms in different phylogenetic lineages of Doridina.

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引用次数: 0

Altitude correlates with dorsal −but not ventral− scale number and dimension in a lacertid lizard

IF 1.6 3区生物学 Q2 ZOOLOGY

Zoology

Pub Date : 2025-02-19 DOI: 10.1016/j.zool.2025.126249

Marco Sannolo , Raquel Ponti

The primary function of the keratinised skin of squamates is modulating heat load, reducing water loss rates and protecting from abrasion. Furthermore, reptilian scale size and shape variation have also been observed depending on the habitat and associated environmental conditions. However, how climate can modulate intraspecific scale characteristics of reptile species in temperate regions is still a subject of debate. Here, we investigate the potential correlation between climate and lizard scalation for a European lacertid lizard. From 221 museum collection specimens of Podarcis muralis, we recorded body measurements and sex information and counted the number and size of dorsal scales and the number of ventral scales per individual. We obtained each specimens’ capture location information from which we extracted environmental data like temperature, precipitation, humidity, wind speed, solar radiation and altitude. We found that individuals that inhabited higher elevations tended to have fewer and larger dorsal scales than those from lowlands, as a potential adaptation to decrease water loss in arid and windy environments. We did not find a correlation between the number of ventral scales and environmental conditions, except for wind speed. This study uncovers an intraspecific adaptive mechanism in an environment gradient that is key to understanding species' potential adaptation to future climatic conditions.

有鳞类动物角质化皮肤的主要功能是调节热负荷、降低失水率和防止磨损。此外，根据栖息地和相关环境条件的不同，爬行动物的鳞片大小和形状也会发生变化。然而，气候如何调节温带地区爬行动物种内的鳞片特征仍是一个争论的话题。在此，我们研究了欧洲一种漆蜥的气候与蜥蜴鳞片之间的潜在相关性。我们从 221 个博物馆收藏的 Podarcis muralis 标本中记录了身体尺寸和性别信息，并统计了每个个体的背鳞数量、尺寸和腹鳞数量。我们获得了每个标本的捕获地点信息，并从中提取了温度、降水、湿度、风速、太阳辐射和海拔等环境数据。我们发现，居住在海拔较高地区的个体背鳞往往比居住在低洼地区的个体更少、更大，这可能是为了适应干旱多风的环境，减少水分流失。除风速外，我们没有发现腹鳞数量与环境条件之间存在相关性。这项研究揭示了环境梯度中的种内适应机制，这对了解物种对未来气候条件的潜在适应性至关重要。

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引用次数: 0

Ontogenetic trajectories and sexual dimorphism of a neotropical ground snake genus Erythrolamprus (Serpentes: Dipsadidae)

IF 1.6 3区生物学 Q2 ZOOLOGY

Zoology

Pub Date : 2025-02-12 DOI: 10.1016/j.zool.2025.126248

Daniel Silva Fernandes , Cristiane Barros Régis

Allometry and sexual dimorphism are potential sources of intraspecific morphological variation. Advances in the methodological framework of geometric morphometrics allow in-depth analysis of these issues, enabling the descriptions and comparisons between groups of multivariate phenotypic attributes and the visualization of allometric trajectories. In the present study, we evaluated the presence of secondary sexual dimorphism in Erythrolamprus miliaris merremi, a semi-aquatic snake occurring in the Atlantic Forest of southeastern Brazil. We assessed linear body measurements and digitized landmarks in the dorsal view of the head of 107 specimens grouped into four categories combining ontogenetic stages and sex. We performed linear models and principal component analyses to estimate and visualize head shape variation and the allometric trajectories of these categories. Adults from both sexes and immature females showed significant static allometry, while immature males showed isometric growth. Although we recovered no sexual dimorphism for head shape, ontogenetic trajectories of both sexes are distinct, with females showing head shape variation throughout ontogenetic development, while males exhibited more conspicuous changes only after sexual maturity. Comparisons with literature data suggest a high degree of variation in ontogenetic allometry of snakes, depending on the phylogenetic group or structure (head/skull) analyzed, while the results for static allometry are more similar between the studied taxa. Only the collection of data on distinct groups of snakes will provide more clues as to whether there is any allometric pattern to these structures, and which factors (evolutionary, ecological or both) are prevalent over it, especially for ontogenetic allometry.

异形和性二态是种内形态变异的潜在来源。几何形态计量学方法框架的进步允许对这些问题进行深入分析，从而能够描述和比较多变量表型属性组之间的差异，并可视化异长轨迹。在本研究中，我们评估了巴西东南部大西洋森林中的一种半水栖蛇类 Erythrolamprus miliaris merremi 是否存在第二性异形。我们评估了 107 个标本的身体线性测量值和头部背面的数字化地标，并将其分为四个类别，结合了个体发育阶段和性别。我们通过线性模型和主成分分析来估计和观察这些类别的头型变化和异速轨迹。成年雌雄个体均表现出显著的静态异长，而未成熟雄体则表现出等距生长。虽然我们没有发现头型的性别二态性，但雌雄个体的个体发育轨迹是不同的，雌性个体在整个个体发育过程中都表现出头型的变化，而雄性个体只有在性成熟后才表现出更明显的变化。与文献数据的比较表明，蛇类的个体发育几何学差异很大，这取决于所分析的系统发育类群或结构（头部/头骨），而所研究类群之间的静态几何学结果较为相似。只有收集不同蛇类群的数据，才能提供更多线索，说明这些结构是否存在任何几何模式，以及哪些因素（进化因素、生态因素或两者兼而有之）对其起主导作用，特别是对个体发育的几何模式。

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引用次数: 0

Comparative display behaviour of the native Iguana delicatissima with the non-native Iguana in the Guadeloupe Archipelago (Lesser Antilles)

IF 1.6 3区生物学 Q2 ZOOLOGY

Zoology

Pub Date : 2025-02-04 DOI: 10.1016/j.zool.2025.126239

Vincent L. Bels , Clément Brousse , Eric Pelle , Jérôme Guerlotté , Marie-Ange Pierre , Florence Kirchhoff , Peter A. Biro

Territorial and mating displays are a key mechanism affecting sexual selection, species recognition, and may affect success of non-native species in the presence of closely related ones. The green Iguana (Iguana iguana) has invaded Caribbean islands from their mainland range, affecting and possibly inter-breeding with native Iguana. However, important display behaviours have not been studied, even though it may be a rare opportunity to study adaptation and evolutionary change. Here, we describe the display-action-patterns (DAP) characterising the head-bob display of the two Iguana species of the Caribbean islands Iguana delicatissima (endemic Lesser Antillean Iguana) and non-native Iguana (closely related non-native species) in the Guadeloupe Archipelago. First, the DAP sequence of non-native Iguana is completely different from mainland animals, with reversed positions of the long and short head bobs. In the non-native Iguana, two long head-bobs (>1.0 s) separated by a highly variable pause (0.1 – 2.8 s) are followed by a series of 3–7 (up to 9) rapid head bobs (<0.5 s), is followed by one phase always with two longer. In native I. delicatissima, the DAP is always initiated with a vibratory gular movement of the extended dewlap in I. delicatissima, but not in the non-native Iguana. Duration of the DAP sequence is significantly shorter in non-native Iguana, always beginning with one singular long head bob (>1.5 s) followed by 3–6 more rapid head bobs. In addition, we observed significant among individual variation in all aspects of the DAP studied, indicating the potential for natural selection to further act on head-bob displays in the non-native and native species. This study now sets the stage to for future studies to determine if behaviour is a cause or consequence of invasion success.

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引用次数: 0

Thermal biology of Indian rock pythons in tropical India

IF 1.6 3区生物学 Q2 ZOOLOGY

Zoology

Pub Date : 2025-02-01 DOI: 10.1016/j.zool.2025.126241

C.S. Vishnu , Chinnasamy Ramesh , Merin Jacob, Vedagiri Thirumurugan , Gautam Talukdar

Temperature plays a crucial role in the physiology of snakes. However, only very limited studies on python thermal biology have been carried out in tropical regions. Here we recorded body temperature (BT) changes of the celomic cavity with respect to atmospheric temperature (AT) and relative humidity (RH) of five Indian Rock pythons Python molurus in the field. The monitoring of the pythons’ thermal ecology lasted throughout 2019 and 2020 and included all seasons i.e., monsoon, post-monsoon and summer. We tagged 13 Pythons with iButtons, but we were only able to retrieve data from five individuals. The AT and RH contributed significantly to the maintenance of the pythons’ BT. Generally, python BT positively related to the AT and negatively to RH i.e., an increasing AT led to an increasing python BT, while an increasing RH led to a decreasing BT. RH played a crucial role in python body temperature regulation; this could be attributed to the high humidity during the rainfall. Python BT varied inter-seasonally and individually, indicating that python BT varied according to the surrounding AT. However, BT differed between the sexes. Our study provides baseline information for further studies on how environmental factors affect the physiology of large -bodied snakes in tropical climates.

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引用次数: 0

The scent of habitat shift: Olfactory receptor evolution is associated with environmental transitions in turtles 栖息地变化的气味：海龟嗅觉受体的进化与环境变化有关。

IF 1.6 3区生物学 Q2 ZOOLOGY

Zoology

Pub Date : 2025-01-01 DOI: 10.1016/j.zool.2024.126236

Alejandro Ibáñez , Joan Garcia-Porta

The transition between aquatic and terrestrial habitats leads to extreme structural changes in sensorial systems. Olfactory receptors (OR) are involved in the detection of odorant molecules both in water and on land. Therefore, ORs are affected by evolutionary habitat transitions experienced by organisms. In this study, we used turtles, a group of vertebrates which inhabit many distinct environments, to explore whether functional olfactory gene receptor repertoires are correlated to habitat. We found that the proportion of class I vs class II functional olfactory receptor genes (used for waterborne odorant detection and volatile odorant detection, respectively) was closely linked to habitat. Fully terrestrial turtles had the largest proportion of class II functional receptor genes while marine turtles had a larger proportion of class I receptor genes. Freshwater turtles had more balanced numbers of class I and class II functional receptor genes, but showed a gradient of OR type proportions likely reflecting species-specific amphibious preferences. Interestingly, freshwater turtles had by far the largest number of functional OR genes compared to those in other habitats, challenging the hypothesis that secondary adaptions to water may have reduced OR repertoires in amniotes. Our study provides novel results which shed new light on the relationship between chemical communication and habitat.

水生和陆地栖息地之间的过渡导致了感觉系统的极端结构变化。嗅觉感受器（OR）参与探测水中和陆地上的气味分子。因此，ORs受到生物体所经历的进化栖息地转变的影响。在这项研究中，我们以海龟这一生活在不同环境中的脊椎动物为研究对象，探讨了功能性嗅觉基因受体是否与栖息地相关。我们发现，ⅰ类和ⅱ类功能性嗅觉受体基因（分别用于水性气味检测和挥发性气味检测）的比例与生境密切相关。全陆龟的II类功能受体基因比例最大，海龟的I类功能受体基因比例较大。淡水龟的I类和II类功能受体基因数量较为平衡，但表现出OR型比例的梯度，可能反映了物种特有的两栖偏好。有趣的是，与其他栖息地的海龟相比，淡水海龟迄今为止拥有最多的功能性OR基因，这挑战了对水的二次适应可能减少羊膜中OR基因的假设。我们的研究提供了新的结果，为化学通讯与栖息地的关系提供了新的思路。

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引用次数: 0