scholarly journals Embryonic development and larval stages of Steindachneridion parahybae (Siluriformes: Pimelodidae): implications for the conservation and rearing of this endangered Neotropical species

2012 ◽  
Vol 10 (2) ◽  
pp. 313-327 ◽  
Author(s):  
Renato M. Honji ◽  
Carlos E. Tolussi ◽  
Paulo H. Mello ◽  
Danilo Caneppele ◽  
Renata G. Moreira
Keyword(s):  
Larval Development ◽  
Average Length ◽  
Larval Growth ◽  
Average Diameter ◽  
Larval Phase ◽  
Larval Stages ◽  
Neotropical Species ◽  
First Feeding ◽  
In Captivity ◽  
Optic Vesicles

Steindachneridion parahybae is a freshwater catfish endemic to the Paraíba do Sul River and is classified as an endangered Neotropical species. An increasing number of conservation biologists are incorporating morphological and physiological research data to help conservation managers in rescue these endangered species. This study investigated the embryonic and larval development of S. parahybae in captivity, with emphasis in major events during the ontogeny of S. parahybae. Broodstocks were artificially induced to reproduce, and the extrusion occurred 200-255 degree-hours after hormonal induction at 24°C. Larval ontogeny was evaluated every 10 minutes under microscopic/stereomicroscopic using fresh eggs samples. The main embryogenic development stages were identified: zygote, cleavage, including the morula, blastula, gastrula phase, organogenesis, and hatching. The extruded oocytes showed an average diameter of 1.10 ± 0.10 mm, and after fertilization and hydration of eggs, the average diameter of eggs increased to about 1.90 ± 0.60 mm, characterized by a large perivitelline space that persisted up to embryo development, the double chorion, and the poles (animal and vegetative). Cell division started about 2 minutes after fertilization (AF), resulting in 2, 4, 8 (4 x 2 arrangement of cells), 16 (4 x 4), 32 (4 x 8) and 64 (2 x 4 x 8) cells. Furthermore, the blastula and gastrula stages followed after these cells divisions. The closed blastopore occurred at 11 h 20 min AF; following the development, the organogenetic stages were identified and subdivided respectively in: early segmentation phase and late segmentation phase. In the early segmentation phase, there was the establishment of the embryonic axis, and it was possible to distinguish between the cephalic and caudal regions; somites, and the optic vesicles developed about 20 h AF. Total hatching occurred at 54 h AF, and the larvae average length was 4.30 ± 0.70 mm. Gradual yolk sac reduction was observed during the first two days of larval development. The first feeding occurred at the end of the second day. During the larval phase, cannibalism, heterogeneous larval growth and photophobia were also observed. This information will be important in improving the artificial reproduction protocols of S. parahybae in controlled breeding programs.

Larval and Early Post-Larval Development of Arctica Islandica

1982 ◽  
Vol 62 (4) ◽  
pp. 745-769 ◽  
Author(s):  
R. A. Lutz ◽  
R. Mann ◽  
J. G. Goodsell ◽  
M. Castagna
Keyword(s):  
Larval Development ◽  
Growth Rates ◽  
Larval Growth ◽  
Ammonium Hydroxide ◽  
Culture Conditions ◽  
Dilute Solution ◽  
Arctica Islandica ◽  
Larval Stages ◽  
Experimental Laboratory ◽  
Rearing Techniques

Mature eggs were stripped from ripe adult specimens of Arctica islandica and exposed to a dilute solution of ammonium hydroxide for various lengths of time before addition of stripped sperm. Larval and early post-larval stages were cultured under experimental laboratory conditions using standard bivalve rearing techniques. Larval cultures were maintained at various controlled temperatures ranging from 8·5 to 14·5 °C. Minimum time to settlement was 32 days at a temperature of approximately 13 °C; at temperatures between 8·5 and 10·0 °C, settlement was not observed until approximately 55 days after fertilization. Larval growth rates were significantly faster at temperatures between 11·0 and 145 °C than at temperatures between 8°C. Morphometry of the larval shell and morphology of the larval hinge apparatus were independent of larval growth rates and experimental culture conditions.

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.

Larval and Early Post-Larval Development of Arctica Islandica

1982 ◽  
Vol 62 (4) ◽  
pp. 745-769 ◽  
Author(s):  
R. A. Lutz ◽  
R. Mann ◽  
J. G. Goodsell ◽  
M. Castagna
Keyword(s):  
Larval Development ◽  
Growth Rates ◽  
Larval Growth ◽  
Ammonium Hydroxide ◽  
Culture Conditions ◽  
Dilute Solution ◽  
Arctica Islandica ◽  
Larval Stages ◽  
Experimental Laboratory ◽  
Rearing Techniques

Mature eggs were stripped from ripe adult specimens of Arctica islandica and exposed to a dilute solution of ammonium hydroxide for various lengths of time before addition of stripped sperm. Larval and early post-larval stages were cultured under experimental laboratory conditions using standard bivalve rearing techniques. Larval cultures were maintained at various controlled temperatures ranging from 8·5 to 14·5 °C. Minimum time to settlement was 32 days at a temperature of approximately 13 °C; at temperatures between 8·5 and 10·0 °C, settlement was not observed until approximately 55 days after fertilization. Larval growth rates were significantly faster at temperatures between 11·0 and 145 °C than at temperatures between 8°C. Morphometry of the larval shell and morphology of the larval hinge apparatus were independent of larval growth rates and experimental culture conditions.

scholarly journals The pelagic life of the pectinid Pecten maximus—a review

2003 ◽  
Vol 60 (2) ◽  
pp. 211-233 ◽  
Author(s):  
M Le Pennec ◽  
A Paugam ◽  
G Le Pennec
Keyword(s):  
Environmental Factors ◽  
Larval Development ◽  
Benthic Community ◽  
Water Mass ◽  
Economic Value ◽  
Pecten Maximus ◽  
Migratory Behaviour ◽  
Larval Phase ◽  
Larval Stages ◽  
Marine Bivalves

Abstract Although marine bivalves go through a planktonic larval phase, knowledge of this phase is often poor because of the difficulty in identifying and monitoring the activity of these tiny organisms within the water mass. Some bivalves have been studied more than others, often because of their economic value. These species can serve as a model for improving our understanding of the circumstances of planktonic larval development, in particular by assessing its impact on recruitment. This review is aimed at summarizing the knowledge on the pelagic life of Pecten maximus acquired by research in France over the last 25 years. The comparison of these results with those obtained elsewhere for pectinid species, indicates certain characteristics that appear to be fairly common to all coastal infralittoral pectinids. Regardless of species, pelagic life of pectinids starts with the release of gametes, followed by fertilization and embryonic and larval stages until metamorphosis and recruitment to the benthic community. After consideration of the main characteristics of the pelagic stages and their sensitivity to certain environmental factors, a graphic synthesis is provided displaying their migratory behaviour and the possible consequences for recruitment.

The missing links: larval and post-larval development of the ascoglossan opisthobranch Elysia viridis

2000 ◽  
Vol 80 (6) ◽  
pp. 1087-1094 ◽  
Author(s):  
Cynthia D. Trowbridge
Keyword(s):  
Larval Development ◽  
Growth Rates ◽  
Shell Length ◽  
Larval Growth ◽  
Model Organism ◽  
Larval Life ◽  
Codium Fragile ◽  
Planktotrophic Larvae ◽  
Algal Diet ◽  
Better Than

The stenophagous ascoglossan (=sacoglossan) opisthobranch Elysia viridis has long been a model organism for the study of endosymbiosis or kleptoplasty as well as one of the few herbivores to consume the introduced green macroalga Codium fragile on European shores. Larval and post-larval dynamics of the ascoglossan were investigated. Planktotrophic larvae of E. viridis grew at 5–10 μm d−1 (shell length) at 15°C on a unicellular algal diet (the cryptophyte Rhodomonas baltica); larvae became competent one month post-hatching. Effective feeding and chloroplast acquisition typically started within 2–3 d of metamorphosis. Slugs grew about 8 mm in the first month of post-larval life. During this period, juveniles held in the light did not grow faster or survive better than conspecifics held in the dark; thus, functional kleptoplasty did not occur during first three weeks of benthic life. While larval growth rates and the nature of metamorphic cues are consistent with those of many other opisthobranch species with planktotrophic larvae, measures of post-larval growth—particularly as it pertains to kleptoplasty—is a new contribution to opisthobranch biology.

scholarly journals amontillado, the Drosophila Homolog of the Prohormone Processing Protease PC2, Is Required During Embryogenesis and Early Larval Development

Genetics ◽  
2003 ◽  
Vol 163 (1) ◽  
pp. 227-237 ◽  
Author(s):  
Lowell Y M Rayburn ◽  
Holly C Gooding ◽  
Semil P Choksi ◽  
Dhea Maloney ◽  
Ambrose R Kidd ◽  
...  
Keyword(s):  
Larval Development ◽  
Secretory Pathway ◽  
Larval Growth ◽  
Peptide Hormones ◽  
Complementation Group ◽  
Prohormone Processing ◽  
Complementation Groups ◽  
Regulated Secretory Pathway ◽  
Processing Protease ◽  
Larval Molt

Abstract Biosynthesis of most peptide hormones and neuropeptides requires proteolytic excision of the active peptide from inactive proprotein precursors, an activity carried out by subtilisin-like proprotein convertases (SPCs) in constitutive or regulated secretory pathways. The Drosophila amontillado (amon) gene encodes a homolog of the mammalian PC2 protein, an SPC that functions in the regulated secretory pathway in neuroendocrine tissues. We have identified amon mutants by isolating ethylmethanesulfonate (EMS)-induced lethal and visible mutations that define two complementation groups in the amon interval at 97D1 of the third chromosome. DNA sequencing identified the amon complementation group and the DNA sequence change for each of the nine amon alleles isolated. amon mutants display partial embryonic lethality, are defective in larval growth, and arrest during the first to second instar larval molt. Mutant larvae can be rescued by heat-shock-induced expression of the amon protein. Rescued larvae arrest at the subsequent larval molt, suggesting that amon is also required for the second to third instar larval molt. Our data indicate that the amon proprotein convertase is required during embryogenesis and larval development in Drosophila and support the hypothesis that AMON acts to proteolytically process peptide hormones that regulate hatching, larval growth, and larval ecdysis.

Development of Camallanus adamsi Bashirullah, 1974 (Nematoda: Camallanidae) in cyclopoid copepods

1976 ◽  
Vol 54 (12) ◽  
pp. 2055-2060 ◽  
Author(s):  
A. K. M. Bashirullah ◽  
Benazir Ahmed
Keyword(s):  
Larval Development ◽  
Intermediate Hosts ◽  
Larval Stages ◽  
Mesocyclops Leuckarti

The larval development of Camallanus adamsi Bashirullah, 1974 was followed in intermediate hosts, Mesocyclops leuckarti (Claus) and Thermocyclops crassus (Fischer), which were kept at 24 °C and 27 °C (average). The nematode molted twice in the haemocoel of copepods. The first molt occurred 117 h after infection at 24 °C and the second molt after 249 h. At 27 °C, the first and the second molts occurred 72 and 168 h respectively after the infection. Three larval stages are described.

Live diet for first feeding of Brazilian sardine, Sardinella brasiliensis (STEINDACHNER, 1879), larvae in captivity

2021 ◽  
Author(s):  
Fabio Carneiro Sterzelecki ◽  
Juliet Kiyoko Sugai ◽  
Jacó Joaquim Mattos ◽  
Roberto Bianchini Derner ◽  
Fabíola Santiago Pedrotti ◽  
...  
Keyword(s):  
First Feeding ◽  
In Captivity

Age Wise Internal Morphometrical Studies on the Heart of Pre-natal Non-descript Sheep

2021 ◽  
Author(s):  
S.K. Sahu ◽  
U.K. Mishra ◽  
S. Sathapathy ◽  
S.M. Nanda
Keyword(s):  
Right Ventricle ◽  
Average Length ◽  
Age Groups ◽  
Circulatory System ◽  
Average Diameter ◽  
Left Ventricular ◽  
Vital Functions ◽  
Internal Parameters ◽  
Measuring Cylinder ◽  
Central Organ

Background: Heart is the central organ of circulatory system that pumps blood into the blood vessels and performs many vital functions. Its development before birth must be studied to safeguard the animal from the occurrence and consequences of various developmental anomalies. The detailed morphometry of different internal parameters of heart especially in pre-natal sheep has not yet been reported. Methods: The foeti of sheep were divided into two age groups viz. mid prenatal (51-100 days) and late prenatal (101 to 150 days) with fifteen animals in each age group. The various internal parameters were recorded by using digital weighing machine, graduated measuring cylinder, digital Vernier’s calliper, non-stretchable nylon thread and graduated scale. The data recorded was statistically analysed by independent t test with IBM SPSS 25.0 version software. Result: The average thickness of left ventricular wall of heart was measured as 2.85±0.15mm and 4.28±0.07mm in mid prenatal and late prenatal stages respectively with significant (p£0.01) differences between the ages. Similarly, the average diameter of left atrio-ventricular opening of heart was measured as 2.06±0.27mm and 6.08±0.36mm in mid prenatal and late prenatal stages respectively with significant (p£0.01) differences between the ages. The average length of septal papillary muscle in right ventricle was measured as 1.12±0.10mm and 3.29±0.21mm in mid prenatal and late prenatal stages respectively with significant (p£0.01) differences between the ages. Further, the average length of moderator band in heart was measured as 1.45±0.11mm and 4.34±0.23mm in mid prenatal and late prenatal stages respectively with significant (p£0.01) differences between the ages. Similarly, the average length of chordae tendinae in right ventricle of heart was measured as 0.97±0.09mm and 3.50±0.34mm in mid prenatal and late prenatal stages respectively with significant (p£0.01) differences between the ages. 

Neurogenesis in the thoracic neuromeres of two crustaceans with different types of metamorphic development

1998 ◽  
Vol 201 (17) ◽  
pp. 2465-2479 ◽  
Author(s):  
S Harzsch ◽  
J Miller ◽  
J Benton ◽  
RR Dawirs ◽  
B Beltz
Keyword(s):  
Embryonic Development ◽  
Larval Development ◽  
Neuronal Development ◽  
Temporal Patterns ◽  
Homarus Americanus ◽  
Spider Crab ◽  
Larval Life ◽  
Larval Stages ◽  
Metamorphic Development ◽  
Embryonic And Larval Development

The mode of embryonic and larval development and the ethology of metamorphosis in the spider crab and the American lobster are very different, and we took advantage of this to compare neuronal development in the two species. The goals of this study were to discover whether the differences in the maturation of the neuromuscular system in the pereopods and the metamorphic changes of motor behavior between the two species are reflected at the level of the developing nervous system ('neurometamorphosis'). Furthermore, we wanted to broaden our understanding of the mechanisms that govern neuronal development in arthropods. Proliferation of neuronal stem cells in thoracic neuromeres 4-8 of the lobster Homarus americanus and the crab Hyas araneus was monitored over the course of embryonic and larval development using the in vivo incorporation of bromodeoxyuridine (BrdU). Neuropil structure was visualized using an antibody against Drosophila synapsin. While proliferation of neuronal precursors has ceased when embryogenesis is 80 % complete (E80%) in the lobster thoracic neuromeres, proliferation of neuroblasts in the crab persists throughout embryonic development and into larval life. The divergent temporal patterns of neurogenesis in the two crustacean species can be correlated with differences in larval life style and in the degree of maturation of the thoracic legs during metamorphic development. Several unusual aspects of neurogenesis reported here distinguish these crustaceans from other arthropods. Lobsters apparently lack a postembryonic period of proliferation in the thoracic neuromeres despite the metamorphic remodeling that takes place in the larval stages. In contrast, an increase in mitotic activity towards the end of embryonic development is found in crabs, and neuroblast proliferation persists throughout the process of hatching into the larval stages. In both E20% lobster embryos and mid-embryonic crabs, expression of engrailed was found in a corresponding set of neurons and putative glial cells at the posterior neuromere border, suggesting that these cells have acquired similar specific identities and might, therefore, be homologous. None of the BrdU-labeled neuroblasts (typically 6-8 per hemineuromere over a long period of embryogenesis) was positive for engrailed at this and subsequent stages. Our findings are discussed in relation to the spatial and temporal patterns of neurogenesis in insects.

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