Larval morphology and development of Aphidius rhopalosiphi (Hymenoptera: Braconidae: Aphidiinae)

2004 ◽  
Vol 136 (2) ◽  
pp. 169-180 ◽  
Author(s):  
Frédéric Muratori ◽  
Jo Le Lannic ◽  
Jean-Pierre Nénon ◽  
Thierry Hance
Keyword(s):  
Developmental Stages ◽  
Morphological Changes ◽  
Abundant Species ◽  
Larval Morphology ◽  
Aphid Parasitoid ◽  
Larval Stages ◽  
Immature Development ◽  
Aphidius Rhopalosiphi ◽  
Cereal Fields ◽  
Parasitoid Development

AbstractThe aphid parasitoid Aphidius rhopalosiphi is the most abundant species of Aphidiinae in cereal fields in northern Europe. Although the larval morphology of other Aphidiinae has been described, the morphology and immature development of A. rhopalosiphi remain unknown. Our goal is to relate growth and larval developmental stages to morphological changes during parasitoid development, using light and scanning electron microscopy. Aphidius rhopalosiphi develops through three larval stages with clear differences in the morphology of the mouthparts, tegument sculpturing, and respiratory features that can be related to the different constraints that the larvae have to face. In the first instar, adaptations to physical combat with competitors take the form of strong mandibles, active caudae, and dorsal spines that allow crawling motion. In the third instar, the larva is adapted to tear tissues with short hooked mandibles and to face aerial respiration. All instars possess sensory structures. The "three instars" hypothesis is supported here by the observation of larvae in exuviation. No differences were found between our observations and descriptions of other Aphidius species, supporting the idea that species of this genus cannot be distinguished by larval morphology but only by morphometric analysis. Some new features of the genus are presented for the first and second instars.

External changes in embryonic and larval development of Odontophrynus cordobae Martino et Sinsch, 2002 (Anura: Cycloramphidae)

Biologia ◽  
2011 ◽  
Vol 66 (6) ◽  
Author(s):  
Pablo Grenat ◽  
Lucio Zavala Gallo ◽  
Nancy Salas ◽  
Adolfo Martino
Keyword(s):  
Larval Development ◽  
Body Mass ◽  
Related Species ◽  
Developmental Stages ◽  
Morphological Changes ◽  
Larval Form ◽  
Larval Stages ◽  
In Captivity ◽  
Mass Increment ◽  
Embryonic And Larval Development

AbstractWe provide the first description of development for a species belonging to Odontophrynus genus by describing all external changes of embryonic and larval stages for Odontophrynus cordobae. External morphological changes through development were analyzed on specimens bred in captivity. Embryonic and larval development, from fertilization to metamorphosis, was completed in 62 days and 46 stages were defined. We split the staging series into ten developmental groups: fertilization (stages 1 and 2); segmentation (stages 3–9); gastrulation (stages 10–12); neurulation (stages 13–16); elongation (stages 17–19); external gill larva (stages 20–24); internal gill larva (stage 25); pre-metamorphosis (stages 26–41); pro-metamorphosis (stage 42); metamorphic climax (stages 43–46). Marked increases in total length were evidenced during elongation and during stage 25, when the tadpole begins to feed. Stage 25 was the longest one (8 days) and it was related to organs rearrangement, morphological progression and body mass increment typical of free life larval form. Similar studies on related species are needed to compare different developmental stages at different taxonomic levels.

scholarly journals Development and Interrogation of a Transcriptomic Resource for the Giant Triton Snail (Charonia tritonis)

2021 ◽  
Author(s):  
AH Klein ◽  
CA Motti ◽  
AK Hillberg ◽  
T Ventura ◽  
P Thomas-Hall ◽  
...  
Keyword(s):  
Developmental Stages ◽  
Cell Signalling ◽  
Natural Populations ◽  
Olfactory Receptors ◽  
Gill Tissue ◽  
Abundant Species ◽  
Population Outbreaks ◽  
Coral Reef Ecosystems ◽  
Specialist Predators ◽  
G Protein Coupled

AbstractGastropod molluscs are among the most abundant species that inhabit coral reef ecosystems. Many are specialist predators, along with the giant triton snail Charonia tritonis (Linnaeus, 1758) whose diet consists of Acanthaster planci (crown-of-thorns starfish), a corallivore known to consume enormous quantities of reef-building coral. C. tritonis are considered vulnerable due to overexploitation, and a decline in their populations is believed to have contributed to recurring A. planci population outbreaks. Aquaculture is considered one approach that could help restore natural populations of C. tritonis and mitigate coral loss; however, numerous questions remain unanswered regarding their life cycle, including the molecular factors that regulate their reproduction and development. In this study, we have established a reference C. tritonis transcriptome derived from developmental stages (embryo and veliger) and adult tissues. This was used to identify genes associated with cell signalling, such as neuropeptides and G protein-coupled receptors (GPCRs), involved in endocrine and olfactory signalling. A comparison of developmental stages showed that several neuropeptide precursors are exclusively expressed in post-hatch veligers and functional analysis found that FFamide stimulated a significant (20.3%) increase in larval heart rate. GPCRs unique to veligers, and a diversity of rhodopsin-like GPCRs located within adult cephalic tentacles, all represent candidate olfactory receptors. In addition, the cytochrome P450 superfamily, which participates in the biosynthesis and degradation of steroid hormones and lipids, was also found to be expanded with at least 91 genes annotated, mostly in gill tissue. These findings further progress our understanding of C. tritonis with possible application in developing aquaculture methods.

scholarly journals Observations on the ciliary currents of the jelly-fish Aurelia aurita L.

1955 ◽  
Vol 34 (2) ◽  
pp. 201-216 ◽  
Author(s):  
A. J. Southward
Keyword(s):  
Morphological Changes ◽  
Aurelia Aurita ◽  
Gastric Cavity ◽  
Larval Stages ◽  
Blind Ending ◽  
Lateral Tract

SUMMARYThe jelly-fish Aurelia aurita possesses external and internal ciliary currents that play a large part in food collection and in the transport of food, reproductive products and excretory matter.Adults feed on relatively small organisms, which are collected in mucus on all external surfaces and eventually passed to the inner surfaces of the oral arms.The inner surfaces of the oral arms bear two ciliated tracts which operate simultaneously in opposite directions. The lateral tract carries food materials proximally towards the gastric pouches, but is capable of rejecting inedible matter. The basal tract carries excretory matter distally, away from the gastric pouches and canals to the exterior.Rejection reactions are also found in the gastric pouches and radial canals, parts of which have currents moving in opposite directions on the roof and on the floor. These opposing currents appear to be derived from the system in the ephyra stage, where the circulation in the wide gastric cavity and blind-ending canals is maintained partly by centripetal currents on the floor and centrifugal currents on the roof.The directions of the main currents remain constant throughout the larval stages to the adult, although slight variations are introduced by morphological changes. The currents also remain the same during spawning, when the eggs and sperm leave the gastric pouches by the normal excretory path.Many of the ciliary currents found in Aurelia are present in other semaeostome and rhizostome medusae, but only in Aurelia do the umbrella surfaces and currents play a large part in food collection.

BIOLOGY OF TACHINAEPHAGUS ZEALANDICUS (HYMENOPTERA: ENCYRTIDAE), PARASITOID OF SYNANTHROPIC DIPTERA

1974 ◽  
Vol 106 (8) ◽  
pp. 785-800 ◽  
Author(s):  
G. S. Olton ◽  
E. F. Legner
Keyword(s):  
Life History ◽  
Developmental Stages ◽  
Average Length ◽  
Host Density ◽  
Adult Emergence ◽  
Reproductive Period ◽  
Laboratory Studies ◽  
Pupal Parasitoid ◽  
History Of ◽  
Parasitoid Development

AbstractThe synonymy, distribution, host range, and life history of the gregarious larval–pupal parasitoid Tachinaephagus zealandicus Ashmead, is discussed. Laboratory studies of its biology were conducted at 25° ± 2 °C using Musca domestica L. as host. Its developmental stages are described. Under laboratory conditions its life cycle lasted 23–27 days. Parasitoid development accelerated with higher average densities per host. Single standardized hosts produced 3–18 adult parasitoids. Mated females provided with hosts lived 50.4–67.2 h. The average length of the reproductive period and number of hosts parasitized were independent of host density; however, the average number of eggs deposited per host increased at lower host densities. Adult emergence displayed circadian rhythmicity independent of photoperiod over 3+ days.

scholarly journals Seasonal occurrence of some larval stages of endoparasites in three cyprinids from the Nwanedi-Luphephe dams, the Limpopo River System, South Africa

2015 ◽  
Vol 52 (3) ◽  
pp. 229-235 ◽  
Author(s):  
E. M. Mbokane ◽  
J. Theron ◽  
W. J. Luus-Powell
Keyword(s):  
Developmental Stages ◽  
River System ◽  
Intestinal Wall ◽  
The Body ◽  
Seasonal Occurrence ◽  
Seasonal Fluctuations ◽  
Metazoan Parasites ◽  
Larval Stages ◽  
Parasite Communities ◽  
Third Stage

Abstract This study provides information on seasonal occurrence of developmental stages of endoparasites infecting three cyprinids in the Nwanedi-Luphephe dams, Limpopo River System. Labeobarbus marequensis (Smith, 1841), Barbus trimaculatus Peters, 1852 and Barbus radiatus Peters, 1853 were investigated seasonally from January 2008 to October 2008. The following larvae of metazoan parasites were collected: Diplostomum sp. from the eyes of L. marequensis and B. trimaculatus; Ornithodiplostomum sp. from the gills of B. trimaculatus; Posthodiplostomum sp. from muscle, skin and fins of B. trimaculatus and B. radiatus; third-stage Contracaecum larvae (L3) from the mesentery fats and on the liver lobes of L. marequensis and B. trimaculatus and gryporynchid cestode larvae from the outer intestinal wall of B. radiatus. All the flukes encountered were metacercariae. Diplostomum sp. and Contracaecum sp. dominated the parasite communities. Their prevalence exhibited seasonal fluctuations with maxima in summer. Factors likely to influence fish infection such as the body size of fish and their condition factors were also briefly considered in this study.

scholarly journals Capture efficiency for small dominant mesozooplankters (Copepoda, Appendicularia) off Buenos Aires Province (34ºS-41ºS), Argentine Sea, using two plankton mesh sizes

2009 ◽  
Vol 57 (3) ◽  
pp. 205-214 ◽  
Author(s):  
Rosana Di Mauro ◽  
Fabiana Capitanio ◽  
María Delia Viñas
Keyword(s):  
Buenos Aires ◽  
Developmental Stages ◽  
Fish Larvae ◽  
Abundant Species ◽  
Accurate Estimation ◽  
Buenos Aires Province ◽  
Oikopleura Dioica ◽  
Great Loss ◽  
Argentine Sea ◽  
Significant Difference

Two plankton mesh sizes of 67 µm and 220 µm were compared to evaluate their efficiency in the capture of the smallest copepods and appendicularians present in the Buenos Aires coastal area (Argentine Sea). A total of 12 copepod species and one appendicularian species were recorded in this study. The copepods were separated into 4 groups: harpacticoids, cyclopoids, small calanoids and large calanoids and their developmental stages. Among the cyclopoids, Oithona nana was the most abundant species, being 96.29 % underestimated by the 220 µm mesh, whereas Microsetella norvegica dominated the harpacticoids and was captured exclusively by the smaller mesh. Similar results were found for copepodites I-III of small calanoids, whose net sampled underestimation reached 99.70%. On the other hand, no significant difference between meshes was found for adults and copepodites IV-V of small calanoids or any of the developmental stages of large calanoids. A great loss of biomass was observed for O. nana when applying the larger mesh. In regards to the appendicularian Oikopleura dioica, all size ranges below 1,000 µm length were better estimated by the 67 µm mesh in terms of abundance and biomass. Our results clearly show that the 67 µm mesh was more efficient in the capture of early stages of small copepods thus providing a more accurate estimation of the fish larvae prey field.

scholarly journals Evaluation of Effective and Practical Euthanasia Methods for Larval African Clawed Frogs (Xenopus laevis)

2020 ◽  
Vol 59 (3) ◽  
pp. 269-274
Author(s):  
Ilana A Galex ◽  
Cameron M Gallant ◽  
Nicole D'Avignon ◽  
Lauren M Kuchenbrod ◽  
Craig A Fletcher ◽  
...  
Keyword(s):  
Xenopus Laevis ◽  
Developmental Stages ◽  
Age Group ◽  
Research Model ◽  
Larval Stages ◽  
Large Numbers ◽  
Guidance Documents ◽  
Stock Solutions ◽  
Tricaine Methanesulfonate ◽  
Tank Water

Larval, or tadpole-stage Xenopus laevis frogs are a popular research model for developmental biology and disease studies. Existing euthanasia guidance documents offer recommendations for both eggs and adult stages, yet do not specifically address the larval stage. Data evaluating effective euthanasia methods for groups of X. laevis tadpoles would therefore be useful. The goal of the current study was to evaluate the efficacy of various immersion euthanasia procedures on tadpoles: tricaine methanesulfonate (MS222) at 6 g/L, eugenol at 800 μL/L and rapid chilling (2 to 4 °C). We also evaluated tadpoles at various developmental stages (NF stages 46, 47 and 49). Tadpoles (n = 70) were exposed to euthanasia solution for 15 min, and controls (n = 40) were placed in housing tank water for 15 min. All animals were then placed in recovery tanks containing housing tank water for 4 h to confirm irreversibility of each agent. Cessation of the heartbeat was assessed at the end of euthanasia solution exposure and at each hour thereafter. We found that immersion in a 6 g/L solution of MS222 resulted in 100% euthanasia of all larval stages tested. Conversely, eugenol produced variable euthanasia rates that were affected by both age group and batches of stock solutions. Rapid chilling was completely ineffective as a euthanasia method in our study. Based on our findings, we recommend MS222 as an effective and practical means of euthanizing large numbers of X. laevis tadpoles.

scholarly journals A taxonomic review of the family Trachipteridae (Acanthomorpha: Lampridiformes), with an emphasis on taxa distributed in the western Pacific Ocean

Zootaxa ◽  
2021 ◽  
Vol 5039 (3) ◽  
pp. 301-351
Author(s):  
JENNIFER M. MARTIN ◽  
ERIC J. HILTON
Keyword(s):  
Pacific Ocean ◽  
Developmental Stages ◽  
Morphological Changes ◽  
Early Life History ◽  
The Body ◽  
Western Pacific ◽  
Western Pacific Ocean ◽  
Taxonomic Review ◽  
The Family ◽  
The Western Pacific

The family Trachipteridae—the Ribbonfishes, Dealfishes, and their relatives—has a circumglobal distribution, with at least 10 species in three genera (Zu Walters & Fitch 1960, Desmodema Walters & Fitch 1960, and Trachipterus Goüan 1770) that are characterized by elongate, extremely laterally compressed bodies, large eyes, absence of ribs, spines on lateral-line scales, greatly protrusible mouths, and a lack of pelvic fins in adults. They are also known for the drastic morphological changes that occur during ontogeny. Trachipterids are poorly represented in collections due to the fragile nature of their bodies. Most studies of the Trachipteridae have been limited by the numbers, developmental stages, and the completeness of the specimens that were examined. Along with the lack of available material, incomplete and conflicting character information compounds the taxonomic confusion of Trachipteridae. Despite the body of regional revisions that have examined trachipterid taxonomy, none have synthesized a suite of morphological characters across ontogeny. The goals of this paper are to (1) revise the family Trachipteridae, (2) revise the genera Trachipterus, Zu, and Desmodema, including information regarding ontogeny and biogeography, and 3) address the alpha taxonomy of Zu, Desmodema, and Trachipterus from the western Pacific Ocean. We recognize possibly five species of Trachipterus as being present in the western Pacific, as well as two species of both Zu and Desmodema. Despite additions to the specimen base that allows refinement of taxonomy and diagnoses, there are still large knowledge gaps associated with the taxonomic review of Trachipteridae. These reflect incomplete understanding of geographic distribution of taxa which may mask unrecognized taxonomic variability. The genus Trachipterus specifically remains problematic and will require greater detailed global study. Early life history stages remain unknown for several taxa which hinders full interpretation of ontogenetic transitions. Protracted transitions, some of which are clarified here, further confuse stage-based diagnoses and must be considered in future analyses of this family.  

scholarly journals A size threshold governs Caenorhabditis elegans developmental progression

2015 ◽  
Vol 282 (1813) ◽  
pp. 20151283 ◽  
Author(s):  
Sravanti Uppaluri ◽  
Clifford P. Brangwynne
Keyword(s):  
Caenorhabditis Elegans ◽  
Food Availability ◽  
Developmental Stages ◽  
Size Control ◽  
Threshold Size ◽  
Larval Stages ◽  
Developmental Progression ◽  
Order Of Magnitude ◽  
Size Threshold ◽  
The Impact

The growth of organisms from humans to bacteria is affected by environmental conditions. However, mechanisms governing growth and size control are not well understood, particularly in the context of changes in food availability in developing multicellular organisms. Here, we use a novel microfluidic platform to study the impact of diet on the growth and development of the nematode Caenorhabditis elegans . This device allows us to observe individual worms throughout larval development, quantify their growth as well as pinpoint the moulting transitions marking successive developmental stages. Under conditions of low food availability, worms grow very slowly, but do not moult until they have achieved a threshold size. The time spent in larval stages can be extended by over an order of magnitude, in agreement with a simple threshold size model. Thus, a critical worm size appears to trigger developmental progression, and may contribute to prolonged lifespan under dietary restriction.

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