The eggs and hatchlings of the octopus Robsonella fontaniana (Cephalopoda: Octopodidae)

2010 ◽  
Vol 91 (3) ◽  
pp. 705-713 ◽  
Author(s):  
Nicolás Ortiz ◽  
María Edith Ré
Keyword(s):  
Embryonic Development ◽  
Developmental Stages ◽  
Atlantic Coast ◽  
Correct Identification ◽  
Life Stages ◽  
Distinctive Pattern ◽  
Early Life Stages ◽  
Early Stages ◽  
History Of ◽  
Second Clutch

Very little is known about the life history of Robsonella fontaniana. In particular, there are no descriptions of the early life stages that enable correct identification of samples taken from the wild. In this work, eggs and hatchlings are described from egg clutches obtained in the field with brooding females and incubated until hatching. Individual eggs exhibited marked differences in stages of embryonic development within egg clutches or even within a single egg string. For one clutch collected at early stages of embryonic development, embryogenesis took 91 days at 11.5 °C and for a second clutch at intermediate developmental stages it took 68 days at 11 °C and 39 days at 14 °C. For the later clutch the hatching period lasts 25 days at 14 °C. The eggs and paralarvae were small, with an egg length of 3.9–5.2 mm, a dorsal mantle length of 2–3 mm and a total paralarvae length of 3.4–6.0 mm. Chromatophore shape and distribution presented a very distinctive pattern. Characteristics of the eggs, egg strings and paralarvae make it possible to distinguish the early stages of R. fontaniana from those of other octopodid species found off the Atlantic coast of Patagonia.

scholarly journals Cnidome and Morphological Features of Pelagia noctiluca (Cnidaria: Scyphozoa) Throughout the Different Life Cycle Stages

2021 ◽  
Vol 8 ◽  
Author(s):  
Ainara Ballesteros ◽  
Carina Östman ◽  
Andreu Santín ◽  
Macarena Marambio ◽  
Mridvika Narda ◽  
...  
Keyword(s):  
Life Cycle ◽  
Developmental Stages ◽  
Later Life ◽  
Life Stages ◽  
Accurate Identification ◽  
Early Stages ◽  
Pelagia Noctiluca ◽  
Life Cycle Stages ◽  
Advanced Stages ◽  
Stage 1

Pelagia noctiluca is considered the most important jellyfish in the Mediterranean Sea, due to its abundance and the severity of its stings. Despite its importance in marine ecosystems and the health problems caused by its massive arrival in coastal areas, little is known about its early life stages and its cnidome has never been described. This study of the morphological and anatomical features throughout the life cycle identifies four early stages: two ephyra and two metaephyra stages. Ephyra stage 1, newly developed from a planula, has no velar canals, gastric filaments or nematocyst batteries. Ephyra stage 2, has velar canals, a cruciform-shaped manubrium and gastric filaments. Metaephyra stage 3 has eight tentacle buds and nematocyst clusters for the first time. Lastly, in metaephyra stage 4, the eight primary tentacles grow nearly simultaneously, with no secondary tentacles. Complete nematocyst battery patterns gradually develop throughout the later life stages. Four nematocyst types are identified: a-isorhiza, A-isorhiza, O-isorhiza and eurytele. Of these, a-isorhiza and eurytele are the most important throughout the entire life cycle, while A-isorhiza and O-isorhiza have a more important role in advanced stages. All nematocysts show a positive correlation between increasing capsule volumes and increasing body diameter of the ephyrae, metaephyrae, young medusae and adult medusae. In the early stages, the volumes of euryteles in the gastric filaments are larger than those in the exumbrella, indicating that the capsule volume is critical in the absence of marginal tentacles, specialized for feeding. This study provides updated information, the most extensive description to date, including high-resolution photographs and schematic drawings of all the developmental stages in the life cycle of P. noctiluca. Additionally, the first cnidome characterization is provided for each stage to facilitate accurate identification of this species when collected in the water column, and to raise awareness of the potential for human envenomation.

scholarly journals Mortality of early life stages of European pilchard Sardina pilchardus along the Atlantic Coast of Northwest Africa (22°30'N-26°N)

2016 ◽  
Vol 51 (3) ◽  
pp. 483-492 ◽  
Author(s):  
Hinde Abdelouahab ◽  
Amina Berraho ◽  
Azeddine Ramzi ◽  
Omar Ettahiri ◽  
Ahmed Errhif ◽  
...  
Keyword(s):  
Early Life ◽  
Atlantic Coast ◽  
Life Stages ◽  
Sardina Pilchardus ◽  
Early Life Stages ◽  
Northwest Africa

scholarly journals Dynamics of venom composition across a complex life cycle

2017 ◽  
Author(s):  
Yaara Y. Columbus-Shenkar ◽  
Maria Y. Sachkova ◽  
Arie Fridrich ◽  
Vengamanaidu Modepalli ◽  
Kartik Sunagar ◽  
...  
Keyword(s):  
Life Cycle ◽  
Developmental Stages ◽  
Complex Life Cycle ◽  
Nematostella Vectensis ◽  
Life Stages ◽  
Early Life Stages ◽  
Sea Anemones ◽  
Sessile Polyp ◽  
Venom Composition ◽  
Production Dynamics

AbstractLittle is known about venom in young developmental stages of animals. The appearance of stinging cells in very early life stages of the sea anemone Nematostella vectensis suggests that toxins and venom are synthesized already in eggs, embryos and larvae of this species. Here we harness transcriptomic and biochemical tools as well as transgenesis to study venom production dynamics in Nematostella. We find that the venom composition and arsenal of toxin-producing cells change dramatically between developmental stages of this species. These findings might be explained by the vastly different ecology of the larva and adult polyp as sea anemones develop from a miniature non-feeding mobile planula to a much larger sessile polyp that predates on other animals. Further, the results suggest a much wider and dynamic venom landscape than initially appreciated in animals with a complex life cycle.

scholarly journals Influence of turbulence and in-stream structures on the transport and survival of grass carp eggs and larvae at various developmental stages

2019 ◽  
Vol 82 (1) ◽  
Author(s):  
Andres F. Prada ◽  
Amy E. George ◽  
Benjamin H. Stahlschmidt ◽  
Patrick Ryan Jackson ◽  
Duane C. Chapman ◽  
...  
Keyword(s):  
Grass Carp ◽  
Early Life ◽  
Developmental Stages ◽  
Shear Stresses ◽  
Life Stages ◽  
Early Life Stages ◽  
Field Collection ◽  
Hydrodynamic Experiments ◽  
Active Swimming ◽  
Eggs And Larvae

AbstractUnderstanding the response of grass carp to flow and turbulence regimes during early life stages is fundamental to monitoring and controlling their spread. A comprehensive set of hydrodynamic experiments was conducted with live grass carp eggs and larvae, to better understand their drifting and swimming patterns with 3 different in-stream obstructions: (1) a gravel bump, (2) a single cylinder, and (3) submerged vegetation. The hydrodynamic behavior of eggs and larvae with each obstruction was continuously monitored for about 85 consecutive hours. Transient spatial distributions of the locations of eggs and larvae throughout the water column were generated for each flow scenario. Results show that the active swimming capabilities of larvae allow them to seek areas of low turbulence and low shear stresses, and that eggs are susceptible to damage by high levels of turbulence, which was further corroborated with tests in an oscillating grid-stirred turbulence tank. Our study seeks to better inform field collection of grass carp during early life stages, and to guide the design of alternative approaches to control the dispersal of this invasive species in North America.

scholarly journals The early life history of fish—there is still a lot of work to do!

2014 ◽  
Vol 71 (4) ◽  
pp. 907-908 ◽  
Author(s):  
Howard I. Browman ◽  
Anne Berit Skiftesvik
Keyword(s):  
Life History ◽  
Early Life ◽  
Larval Fish ◽  
Fish Larvae ◽  
Early Life History ◽  
Life Stages ◽  
Early Life Stages ◽  
Relative Contribution ◽  
History Of ◽  
Fish Early Life Stages

Abstract The themed set of articles that follows this introduction contains a selection of the papers that were presented at the 36th Annual Larval Fish Conference (ALFC), convened in Osøyro, Norway, 2–6 July 2012. The conference was organized around four theme sessions, three of which are represented with articles in this collection: “Assessing the relative contribution of different sources of mortality in the early life stages of fishes”; “The contribution of mechanistic,behavioural, and physiological studies on fish larvae to ecosystem models”; “Effects of oil and natural gas surveys, extraction activity and spills on fish early life stages”. Looking back at the main themes of earlier conferences about the early life history of fish reveals that they were not very different from those of ALFC2012. Clearly, we still have a lot of work to do on these and other topics related to the biology and ecology of fish early life stages.

Effect of developmental stage and peloton morphology on success in isolation of mycorrhizal fungi in Caladenia formosa (Orchidaceae)

2004 ◽  
Vol 52 (2) ◽  
pp. 231 ◽  
Author(s):  
T. T. Huynh ◽  
A. C. Lawrie ◽  
F. Coates ◽  
C. B. McLean
Keyword(s):  
Mycorrhizal Fungi ◽  
Early Life ◽  
Developmental Stages ◽  
Life Stages ◽  
Early Life Stages ◽  
Terrestrial Orchid ◽  
Leaf Production ◽  
Fruiting Stage ◽  
One Year ◽  
Scanning Electron

Six developmental stages (leafing, budding, flowering, fruiting, senescence and dormancy) were chosen in the threatened terrestrial orchid Caladenia formosa G.W.Carr to optimise isolation of effective fungi. Loose (undigested) pelotons were observed by scanning electron microscopy in the old tuber and collar, suggesting a role in infection of new tissue. In collars collected at early life stages (leafing, budding, flowering), pelotons had loosely coiled hyphae that were uniformly fine (1–2 μm diameter), with or without monilioid cells. In collars collected from older life stages (fruiting, senescence), pelotons had increasing proportions (up to 94%) of clumped fine hyphae. Coarser hyphae (4–6 μm diameter) were also present in the fruiting stage in one year. Only fungi isolated from single pelotons in collars of early life stages (leafing, budding, flowering) had fine hyphae with monilioid cells and induced seed germination (to green leaf production). Sectioned protocorms had pelotons of fine, loosely coiled hyphae with monilioid cells, as in field-collected material from early life stages. This suggests that the most effective fungi for conservation of this orchid are likely to be isolated from pelotons of loose fine hyphae with monilioid cells from leafing to flowering stages.

scholarly journals Embryonic development and perinatal skeleton in a limbless, viviparous lizard, Anguis fragilis (Squamata: Anguimorpha)

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11621
Author(s):  
Tomasz Skawiński ◽  
Grzegorz Skórzewski ◽  
Bartosz Borczyk
Keyword(s):  
Embryonic Development ◽  
Vertebral Column ◽  
Developmental Stages ◽  
The State ◽  
Phylogenetic Position ◽  
Limited Attention ◽  
Relative Importance ◽  
Mode Of Reproduction ◽  
History Of ◽  
Anguis Fragilis

Despite the long history of embryological studies of squamates, many groups of this huge clade have received only limited attention. One such understudied group is the anguimorphs, a clade comprising morphologically and ecologically very diverse lizards. We describe several stages of embryonic development of Anguis fragilis, a limbless, viviparous anguimorph. Interestingly, in several clutches we observe high morphological variation in characters traditionally important in classifying embryos into developmental stages. The causes of this variation remain unknown but environmental factors do not seem to be very important. Additionally, we describe the state of ossification in several perinatal specimens of A. fragilis. The cranial skeleton is relatively poorly ossified around the time of birth, with all of the bones constituting the braincase unfused. On the other hand, the vertebral column is well ossified, with the neurocentral sutures closed and the neural arches fused in all postatlantal vertebrae. Such an advanced state of ossification may be related to the greater importance of the vertebral column in locomotion in limbless species than in ones with fully-developed limbs. Numerous factors seem to affect the state of ossification at the time of hatching or birth in squamates, including phylogenetic position, mode of reproduction and, potentially, limblessness. However, data from a greater number of species are needed to reach firmer conclusions about the relative importance of these variables in certain clades.

scholarly journals The effects of familiarity on escape responses in the Trinidadian guppy (Poecilia reticulata)

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3899 ◽  
Author(s):  
Hayley L. Wolcott ◽  
Alfredo F. Ojanguren ◽  
Miguel Barbosa
Keyword(s):  
Early Life ◽  
Escape Response ◽  
Poecilia Reticulata ◽  
Test Group ◽  
Life Stages ◽  
Early Life Stages ◽  
Early Stages ◽  
Reactive Distance ◽  
Escape Responses ◽  
Predator Evasion

Predation is the main cause of mortality during early life stages. The ability to avoid and evade potential threats is, therefore, favoured to evolve during the early stages of life. It is also during these early stages that the process of familiarization occurs. It has long been recognized that associating with familiar individuals confers antipredator benefits. Yet gaps in our knowledge remain about how predator evasion is affected by social experience during early stages. In this study, we test the hypothesis that familiarization acquired during early life stages improves escape responses. Using the guppy Poecilia reticulata, we examine the effect of different recent social conditions in the three main components of predator evasion. Using high-speed motion analysis, we compared the number of individuals in each test group that responded to a visual stimulus, their reactive distance and magnitude of their response (maximum speed, maximum acceleration and distance) in groups composed either of familiar or non-familiar individuals. Contrary to the prediction, groups composed of familiar individuals were less responsive than groups of unfamiliar individuals. Reactive distance and magnitude of response were more dependent on individual size rather than on familiarity. Larger individuals reached higher maximum speeds and total distances in their escape response. Our result indicates that familiarity is likely to affect behaviour earlier in a predator-prey interaction, which then affects the behavioural component of the response. Taken together, our study contributes to previous ones by distinguishing which components of an escape response are modulated by familiarity.

Life history of Amblyseius fustis (Pritchard and Baker), an indigenous predator of the cassava red mite, Oligonychus gossypii (zacher) in south western Nigeria

1985 ◽  
Vol 6 (2) ◽  
pp. 193-197 ◽  
Author(s):  
T. O. Ezulike ◽  
J. A. Odebiyi
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Relative Humidity ◽  
Developmental Stages ◽  
Developmental Period ◽  
Life Stages ◽  
Male And Female ◽  
Significant Difference ◽  
History Of ◽  
Male To Female

AbstractThe life history of Amblyseius fustis (Pritchard and Baker) was studied in the laboratory at a fluctuating temperature and relative humidity ranging from 24.4 to 28.0°C and 55.5 to 75.6%, respectively. The developmental stages consist of egg, larva, protonymph, deutonymph and adult. The life cycle, from egg to adult of both male and female was about 8 days, while longevity was about 19.2 days. Mated female laid an average of 18.8 eggs. There was no significant difference in the longevity and fecundity of predators fed on different life stages of the host. The proportion of male to female in the progeny of mated females was 1:4.A. fustis has a shorter developmental period and lives longer than its prey, but the latter is more fecund (26.9 eggs/♀) and has a higher proportion of females in its progeny (1:4.8). The shorter developmental period and the longer life span of the predator are likely to offset the higher fecundity of the prey.

scholarly journals Hierarchical analysis of ontogenetic time to describe heterochrony and taxonomy of developmental stages

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Guillaume Lecointre ◽  
Nalani K. Schnell ◽  
Fabrice Teletchea
Keyword(s):  
Early Life ◽  
Developmental Stages ◽  
Reproductive Traits ◽  
Freshwater Species ◽  
Life Stages ◽  
Hierarchical Analysis ◽  
Early Life Stages ◽  
Time Segment ◽  
High Consistency ◽  
Species Specific

AbstractEven though an accurate description of early life stages is available for some teleostean species in form of embryonic and post-embryonic developmental tables, there is poor overlap between species-specific staging vocabularies beyond the taxonomic family level. What is called “embryonic period”, “larval period”, “metamorphosis”, or “juvenile” is anatomically different across teleostean families. This problem, already pointed out 50 years ago, challenges the consistency of developmental biology, embryology, systematics, and hampers an efficient aquaculture diversification. We propose a general solution by producing a proof-of-concept hierarchical analysis of ontogenetic time using a set of four freshwater species displaying strongly divergent reproductive traits. With a parsimony analysis of a matrix where “operational taxonomic units” are species at a given ontogenetic time segment and characters are organs or structures which are coded present or absent at this time, we show that the hierarchies obtained have both very high consistency and retention index, indicating that the ontogenetic time is correctly grasped through a hierarchical graph. This allows to formally detect developmental heterochronies and might provide a baseline to name early life stages for any set of species. The present method performs a phylogenetic segmentation of ontogenetic time, which can be correctly seen as depicting ontophylogenesis.

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