The oviposition of eight individuals of Anaplectella ruficollis (Karny, 1915), one at a time, was observed in 170 ml clean cups set at room temperature (22–27ºC) and under fluorescent light. ...Anaplectella ruficollis produces pale brown ootheca which are rotated clockwise. 15–35 minutes, the ootheca has rotated 90º. The ootheca is then retracted into the abdomen for 58–72 minutes. After 2–11 days, the brown-colored ootheca is laid and covered with the substrate. The oviposition behavior of Anaplectella ruficollis observed in this study is unique once the ootheca is retracted into the abdomen. Although it is thought to be closely related to ovoviviparity, it is still appropriate to classify it as oviparous A. This was because the ootheca had a rigid oothecal membrane and serrated keel, and the females dropped the ootheca well before the hatch. Additionally, form of ootheca was asymmetrical from left to right and bordered by the suture line, which suggests an advantage to the traits for retraction into the abdomen.
ABSTRACT The purpose of this study is to describe, in detail, the ultrastructure of the infundibulum of the sexually mature and active female green iguana, Iguana iguana . The infundibulum of five ...iguanas was remarkably distinct from the uterus, and was also clearly demarcated into cranial (expanded v‐shaped) and caudal (tubular) divisions. Tissue samples obtained from five portions (three from the cranial division and two from the caudal division) of the infundibulum were processed conventionally for light and electron microscopy. The epithelial lining of the most anterior, middle, and posterior, parts of the cranial division displayed nonciliated cells predominantly, and occasionally ciliated cells. The numerous secretory granules in nonciliated type 1 cell found in the fimbrial aspect of the infundibulum were homogenous and deeply electron‐dense, but those in the other two regions were variants of this cell type because they contained variably electron‐dense secretory granules. Two main types of nonciliated cells (type 2 and its variant, type 3, as well as type 4) occurred in the epithelial lining of the caudal division of the infundibulum, but they, clearly, showed no dense secretory granules. Whereas the nonciliated type 2 cell and its variant (type 3 cell) contained large glycogen deposits, the type 4 cell lacked these deposits but its apical part contained large lipid‐like droplets and, remarkably, blebbed into the duct lumen. The nonciliated cells lining the mucosal tubular glands contained highly electron‐dense secretory granules, which were similar to those found in the nonciliated type 1 cell in the epithelial lining of the fimbrial part of the cranial division of the infundibulum.
Can oviposition on marine litter pose a threat to marine fishes? De-la-Torre, Gabriel Enrique; Valderrama-Herrera, Miguel; Urizar Garfias Reyes, Damarisch Fernanda ...
Marine pollution bulletin,
December 2022, 2022-12-00, 20221201, Letnik:
185
Journal Article
Recenzirano
Marine litter colonization is widely investigated as an important pathway for the dispersal of potentially invasive species. However, this phenomenon may be impacting marine biota in other ways as ...well. In this viewpoint, we express our concerns regarding the potential loss of viable eggs of numerous oviparous fishes deposited on marine litter when large-scale stranding events occur. Our concerns are supported by personal observations of stranded marine litter harboring fresh and viable egg capsules (Sympterygia sp.) and eggs (Family: Blenniidae), as well as reports in the literature. The loss of viable eggs from oviparous fishes is widely overlooked and poorly understood. Based on these knowledge gaps, we make a call for research and propose several research priorities to understand the impact of these events.
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•Fish from various taxa deposit their eggs on marine litter.•Oviposited marine litters wash ashore during stranding events.•A significant number of viable eggs on stranded marine litter are lost.•Research priorities in this line of research are discussed.
Survival of the immobile embryo in response to rising temperature is important to determine a species' vulnerability to climate change. However, the collective effects of 2 key thermal ...characteristics associated with climate change (i.e., rising average temperature and acute heat events) on embryonic survival remain largely unexplored. We used empirical measurements and niche modeling to investigate how chronic and acute heat stress independently and collectively influence the embryonic survival of lizards across latitudes. We collected and bred lizards from 5 latitudes and incubated their eggs across a range of temperatures to quantify population-specific responses to chronic and acute heat stress. Using an embryonic development model parameterized with measured embryonic heat tolerances, we further identified a collective impact of embryonic chronic and acute heat tolerances on embryonic survival. We also incorporated embryonic chronic and acute heat tolerance in hybrid species distribution models to determine species' range shifts under climate change. Embryos' tolerance of chronic heat (T-chronic) remained consistent across latitudes, whereas their tolerance of acute heat (T-acute) was higher at high latitudes than at low latitudes. Tolerance of acute heat exerted a more pronounced influence than tolerance of chronic heat. In species distribution models, climate change led to the most significant habitat loss for each population and species in its low-latitude distribution. Consequently, habitat for populations across all latitudes will shift toward high latitudes. Our study also highlights the importance of considering embryonic survival under chronic and acute heat stresses to predict species' vulnerability to climate change.
Marine litter, including plastic litter, represent a serious environmental problem at a global scale. Plastics in marine litter have been documented on few occasions as serving as a unique substrate ...for fish oviposition in the oceans. The main goal of this viewpoint is to add to the previous discussion of fish oviposition and marine litter concerns by pointing out current research needs.
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•Marine litter is regarded as a unique oviposition-site for fish.•Stranded oviposited marine litters imperil endangered species population.•Embryo development on marine plastic debris merits scientific attention.•Oviposition of fish on marine litter: a double-edged sword.
El patrón reproductivo es una de las principales características de la historia de vida de los organismos. Este patrón depende tanto de historia evolutiva de los organismos como de los factores ...externos. Se estudió la reproducción de Liolaemus espinozai en Campo El Arenal, Catamarca. Se analizó el ciclo reproductivo y de los cuerpos grasos de machos y hembras y sus relaciones con la temperatura, fotoperíodo y precipitación. La especie es ovípara y exhibe un patrón reproductivo estacional típico de primavera - verano, con ovulación y fecundación de primavera y puesta y eclosión de verano. La actividad reproductiva de las hembras empieza en noviembre con folículos vitelogénicos; desde diciembre pueden observarse huevos en oviducto y a mediados de enero hasta principios de febrero aparecen hembras con oviducto distendido. Los machos presentan actividad desde fines de septiembre con máximo volumen testicular hasta noviembre, luego estos valores descienden hasta su expresión mínima entre enero y marzo. El tamaño de la puesta varió de 2 a 7 huevos y se correlacionó con el tamaño de la hembra indicando una tendencia a que individuos mayores tengan posturas mayores. La especie muestra un patrón con características similares a lo encontrado para especies filogenéticamente cercanas.
•Urban lizards had higher ectoparasite loads and laid a higher proportion of unfertilized eggs.•Eggs from urban lizards had higher immune parameters in the yolk.•Egg mass and egg viability are ...important predictors of egg yolk physiology.•Maternal immune challenge altered egg yolk oxidative status in urban animals.
Urbanization can cause innumerable abiotic and biotic changes that have the potential to influence the ecology, behavior, and physiology of native resident organisms. Relative to their rural conspecifics, urban Side-blotched Lizard (Uta stansburiana) populations in southern Utah have lower survival prospects and maximize reproductive investment via producing larger eggs and larger clutch sizes. While egg size is an important predictor of offspring quality, physiological factors within the egg yolk are reflective of the maternal environment and can alter offspring traits, especially during energetically costly processes, such as reproduction or immunity. Therefore, maternal effects may represent an adaptive mechanism by which urban-dwelling species can persist within a variable landscape. In this study, we assess urban and rural differences in egg yolk bacterial killing ability (BKA), corticosterone (CORT), oxidative status (d-ROMs), and energy metabolites (free glycerol and triglycerides), and their association with female immune status and egg quality. Within a laboratory setting, we immune challenged urban lizards via lipopolysaccharide injection (LPS) to test whether physiological changes associated with immune system activity impacted egg yolk investment. We found urban females had higher mite loads than rural females, however mite burden was related to yolk BKA in rural eggs, but not urban eggs. While yolk BKA differed between urban and rural sites, egg mass and egg viability (fertilized vs. unfertilized) were strong predictors of yolk physiology and may imply tradeoffs exist between maintenance and reproduction. LPS treatment caused a decrease in egg yolk d-ROMs relative to the control treatments, supporting results from previous research. Finally, urban lizards laid a higher proportion of unfertilized eggs, which differed in egg yolk BKA, CORT, and triglycerides in comparison to fertilized eggs. Because rural lizards laid only viable eggs during this study, these results suggest that reduced egg viability is a potential cost of living in an urban environment. Furthermore, these results help us better understand potential downstream impacts of urbanization on offspring survival, fitness, and overall population health.
The lowland populations of the viviparous lizard Zootoca vivipara in the Carpathian Basin occur in cold, marshy relict habitats. In one of the largest wetlands in Hungary, Kis-Balaton, in 2016 its ...presence was confirmed by catching an individual with a small mammal live-trap. This new record is significant, since the nearest known sites of occurrence are at great distance and it is situated between the lowland viviparous populations of the north-northeast and the oviparous populations of the south (in Croatia).
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