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.

Transport, Distribution, and Abundance of Larval and Juvenile Walleye Pollock (Theragra chalcogramma) in the Western Gulf of Alaska

1991 ◽  
Vol 48 (1) ◽  
pp. 91-98 ◽  
Author(s):  
Sarah Hinckley ◽  
Kevin M. Bailey ◽  
Susan J. Picquelle ◽  
James D. Schumacher ◽  
Phyllis J. Stabeno
Keyword(s):  
Early Life ◽  
Gulf Of Alaska ◽  
Walleye Pollock ◽  
Theragra Chalcogramma ◽  
Life Stages ◽  
Early Life Stages ◽  
Early Juvenile ◽  
Walleye Pollock Theragra Chalcogramma ◽  
Eggs And Larvae ◽  
Egg Abundance

The spawning distribution of walleye pollock (Theragra chalcogramma) and subsequent southwesterly drift of eggs, larvae, and juveniles were investigated in Shelikof Strait, March–September 1987. In mid-March, a hydroacoustics survey found that spawning adults were concentrated in the deeper parts of Shelikof Strait, as were eggs collected in this area during an ichthyoplankton survey about 1 mo later. In May, a concentration of young larvae was found 100–150 km to the southwest of the spawning area. In late June and early July, the center of distribution of late larval and early juvenile walleye pollock was further to the southwest, between the Shumagin and Semidi Islands. By August and September, juveniles were mostly distributed downstream of the Shumagin Islands. The rate of drift of eggs and larvae through June was estimated at 4–6 cm/s. The trajectories of satellite-tracked buoys deployed in the region of greatest egg abundance revealed similar patterns to those of the early life stages of walleye pollock. These observations demonstrate that transport is an important factor determining the distribution of pollock larvae in downstream coastal nursery areas.

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 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.

scholarly journals Dimethoate 40% organosphosphorous pesticide toxicity in Prochilodus lineatus (Prochilodontidae, Characiformes) eggs and larvae

2006 ◽  
Vol 66 (2b) ◽  
pp. 633-640 ◽  
Author(s):  
A. F. Campagna ◽  
M. N. Eler ◽  
E. L. G. Espíndola ◽  
J. A. Senhorini ◽  
R. F. do Rêgo ◽  
...  
Keyword(s):  
Early Life ◽  
Toxicity Tests ◽  
Ache Inhibitor ◽  
South American ◽  
Life Stages ◽  
Early Life Stages ◽  
Organophosphate Insecticide ◽  
Prochilodus Lineatus ◽  
Acetylcholinesterase Enzyme ◽  
Eggs And Larvae

Toxicity tests using early life stages of fish are of great importance in assessing risks to growth, reproduction and survival in polluted environments and are important tools for good environmental monitoring. However, a small number of standard bioassays of this type have been developed in Brazil. Curimbatá (Prochilodus lineatus) is an abundant South American characid fish of great commercial interest. It was chosen for testing different concentrations of 40% dimethoate, an organophosphate insecticide and acetylcholinesterase enzyme (AChE) inhibitor used widely in Brazil. The 48-h LC50 for eggs is higher than 16.0 µg.L-1, whereas for recently hatched larvae it was found to be significantly lower (11.81 µg.L-1, ranging between 10.23 µg.L-1 - 13.65 µg.L-1) and also significantl y lower than that for eggs by a Student t-test for independent samples (p = 0.03). The 96-h LC50 for 3-day old larvae was 10.44 µg.L-1 (8.03 µg.L-1 - 13.57 µg.L-1), similar to that of recently-hatched larvae (p = 0.76). Larval mobility was also found to be reduced by this insecticide.

Early life stages of Calanus pacificus are neither exposed nor sensitive to low pH waters

2019 ◽  
Vol 41 (6) ◽  
pp. 893-896
Author(s):  
Anna K McLaskey ◽  
Paul McElhany ◽  
D Shallin Busch ◽  
Michael Maher ◽  
Amanda K Winans ◽  
...  
Keyword(s):  
Early Life ◽  
Puget Sound ◽  
Individual Variability ◽  
Ph Effects ◽  
Life Stages ◽  
Early Life Stages ◽  
Calanus Pacificus ◽  
Small Decline ◽  
The Vertical Distribution ◽  
Eggs And Larvae

Abstract We characterized the vertical distribution of Calanus pacificus eggs and larvae and the carbonate chemistry that they are exposed to in Puget Sound, WA. We found that, under stratified conditions, more than 90% of eggs and nauplii stages 1–4 were distributed above the pycnocline, in seawater with pH higher than 7.7. In addition, eggs and larvae from 101 females were reared for 5 days under a range of pH conditions (7.2–8.0) to investigate how pH sensitivity varies among individuals. We observed a slight increase in naupliar survival at pH 7.3 in Individual Brood experiments, while in Mixed Brood experiments, exposure to pH 7.3 led to a small decline in hatching success. In a Split Brood experiment, inter-individual variability among different females’ broods masked pH effects. These results indicate that C. pacificus early life stages are generally tolerant to short-term direct effects of ocean acidification.

Evaluation of Tests with Early Life Stages of Fish for Predicting Long-Term Toxicity

1977 ◽  
Vol 34 (8) ◽  
pp. 1148-1154 ◽  
Author(s):  
James M. McKim
Keyword(s):  
Water Quality ◽  
Life Cycle ◽  
Early Life ◽  
Developmental Stages ◽  
Quality Criteria ◽  
Toxicity Tests ◽  
Water Quality Criteria ◽  
Life Stages ◽  
Early Life Stages ◽  
Aquatic Life

Partial and complete life-cycle toxicity tests with fish, involving all developmental stages, have been used extensively in the establishment of water-quality criteria for aquatic life. During extended chronic exposures of fish to selected toxicants, certain developmental stages have frequently shown a greater sensitivity than others. In 56 life-cycle toxicity tests completed during the last decade with 34 organic and inorganic chemicals and four species of fish, the embryo–larval and early juvenile life stages were the most, or among the most, sensitive. Tests with these stages can be used to estimate the maximum acceptable toxicant concentration (MATC) within a factor of two in most cases. Therefore, toxicity tests with these early life stages of fish should be useful in establishing water-quality criteria and in screening large numbers of chemicals. Key words: fish, embryos, larvae, chronic toxicity, early life stages

scholarly journals Differences among families in craniofacial shape at early life-stages of Arctic charr (Salvelinus alpinus)

2020 ◽  
Author(s):  
Samantha Victoria Beck ◽  
Katja Räsänen ◽  
Camille A. Leblanc ◽  
Skúli Skúlason ◽  
Zophonías O. Jónsson ◽  
...  
Keyword(s):  
Early Life ◽  
Egg Size ◽  
Developmental Stages ◽  
Salvelinus Alpinus ◽  
Arctic Charr ◽  
Life Stage ◽  
Early Life Stage ◽  
Offspring Size ◽  
Life Stages ◽  
Early Life Stages

Abstract Background Organismal fitness can be determined at early life-stages, but phenotypic variation at early life-stages is rarely considered in studies on evolutionary diversification. The trophic apparatus has been shown to contribute to sympatric resource-mediated divergence in several taxa. However, processes underlying diversification in trophic traits are poorly understood. Using phenotypically variable Icelandic Arctic charr (Salvelinus alpinus), we reared offspring from multiple families under standardized laboratory conditions and tested to what extent family (i.e. direct genetic and maternal effects) contributes to offspring morphology at hatching (H) and first feeding (FF). To understand the underlying mechanisms behind early life-stage variation in morphology, we examined how craniofacial shape varied according to family, offspring size, egg size and candidate gene expression. Results Craniofacial shape (i.e. the Meckel’s cartilage and hyoid arch) was more variable between families than within families both across and within developmental stages. Differences in craniofacial morphology between developmental stages correlated with offspring size, whilst within developmental stages only shape at FF correlated with offspring size, as well as female mean egg size. Larger offspring and offspring from females with larger eggs consistently had a wider hyoid arch and contracted Meckel’s cartilage in comparison to smaller offspring.Conclusions This study provides evidence for family-level variation in early life-stage trophic morphology, indicating the potential for parental effects to facilitate resource polymorphism.

scholarly journals Differences among families in craniofacial shape at early life-stages of Arctic charr (Salvelinus alpinus)

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Samantha V. Beck ◽  
Katja Räsänen ◽  
Camille A. Leblanc ◽  
Skúli Skúlason ◽  
Zophonías O. Jónsson ◽  
...  
Keyword(s):  
Early Life ◽  
Egg Size ◽  
Developmental Stages ◽  
Salvelinus Alpinus ◽  
Arctic Charr ◽  
Life Stage ◽  
Early Life Stage ◽  
Offspring Size ◽  
Life Stages ◽  
Early Life Stages

Abstract Background Organismal fitness can be determined at early life-stages, but phenotypic variation at early life-stages is rarely considered in studies on evolutionary diversification. The trophic apparatus has been shown to contribute to sympatric resource-mediated divergence in several taxa. However, processes underlying diversification in trophic traits are poorly understood. Using phenotypically variable Icelandic Arctic charr (Salvelinus alpinus), we reared offspring from multiple families under standardized laboratory conditions and tested to what extent family (i.e. direct genetic and maternal effects) contributes to offspring morphology at hatching (H) and first feeding (FF). To understand the underlying mechanisms behind early life-stage variation in morphology, we examined how craniofacial shape varied according to family, offspring size, egg size and candidate gene expression. Results Craniofacial shape (i.e. the Meckel’s cartilage and hyoid arch) was more variable between families than within families both across and within developmental stages. Differences in craniofacial morphology between developmental stages correlated with offspring size, whilst within developmental stages only shape at FF correlated with offspring size, as well as female mean egg size. Larger offspring and offspring from females with larger eggs consistently had a wider hyoid arch and contracted Meckel’s cartilage in comparison to smaller offspring. Conclusions This study provides evidence for family-level variation in early life-stage trophic morphology, indicating the potential for parental effects to facilitate resource polymorphism.

scholarly journals Buccal apparatus and gastrointestinal tract dimensions associated to the diet of early life stages of Centropomus undecimalis (Centropomidae, Actinopterygii)

2011 ◽  
Vol 101 (1-2) ◽  
pp. 85-92 ◽  
Author(s):  
Isabela M. S Araújo ◽  
Elisabeth C Silva-Falcão ◽  
William Severi
Keyword(s):  
Gastrointestinal Tract ◽  
Early Life ◽  
Developmental Stages ◽  
Northern Coast ◽  
Life Stages ◽  
Early Life Stages ◽  
Digestive Tube ◽  
Centropomus Undecimalis ◽  
Food Items ◽  
Gape Size

The present study aims to compare the buccal apparatus and gastrointestinal tract of early life stages of Centropomus undecimalis (Bloch, 1792), and relate them to its diet. A total of 190 individuals collected with a channel net in the Catuama estuary (07º40'9.9''S, 34º50'36.7''W), northern coast of the state of Pernambuco, were examined. Morphometrical and meristic data were analyzed for the two initial developmental periods (larval and juvenile). Their digestive tube was morphologically characterized and its content identified. The longest transverse axis of food items was measured, and compared to the standard length (SL) and mouth gape size (D) of the individuals. Body measurement regressions differed significantly (p<0.001) between larvae and juveniles. The stomachs with food content (n=118 individuals) presented a proportion of 62% full and 30% empty (being 8% damaged). They differed in relation to the fullness level and presented a coiled shape when empty. The number of food items in relation to SL and D did not present an evident correlation. Larvae (SL<10 mm) feed on small copepods, while juveniles (SL=11.1 to 64.7 mm) ingest larvae of various decapod species, showing a distinct diet between these initial developmental stages.

Spatiotemporal distribution of anchovy early life stages in the eastern part of the Adriatic Sea in relation to some oceanographic features

2018 ◽  
Vol 99 (5) ◽  
pp. 1205-1211 ◽  
Author(s):  
B. Zorica ◽  
V. Čikeš Keč ◽  
A. Pešić ◽  
S. Gvozdenović ◽  
J. Kolitari ◽  
...  
Keyword(s):  
Early Life ◽  
Adriatic Sea ◽  
Geometric Mean ◽  
Temporal Distribution ◽  
Significant Negative Correlation ◽  
Spatial And Temporal Distribution ◽  
Life Stages ◽  
Early Life Stages ◽  
Eggs And Larvae ◽  
Egg Abundance

AbstractDuring the summer of 2013 two scientific surveys (northern, at the beginning of July and southern, at the end of July) were carried out along the eastern Adriatic Sea. In these surveys, ichthyoplankton samples of anchovy (Engraulis encrasicolus, Linnaeus 1758) eggs and larvae were collected. In the whole investigated area, egg and larvae abundance varied from 2.61 to 1040.24 eggs m−2 (geometric mean ± CL: 25.43 ± 1.48 eggs m−2) and 2.73 larvae m−2 to 611.14 larvae m−2 (geometric mean ± CL: 17.07 ± 1.41 larvae m−2), respectively. Higher abundance of anchovy early life stages was noted in the northern part of the investigated area. The length of the collected specimens lay within the range of 2.39–3.68 mm and those individuals were less than 12 h old. Analysis of spatial and temporal distribution of collected anchovy early life stages indicated their higher abundance in areas of upwelling (four areas were distinguished on the eastern Adriatic side). Larger and older specimens were collected at the beginning of July in the northern part of Adriatic indicating that the anchovy population in the Adriatic tends to shift among its spawning centres in this area. In general, anchovy eggs were accompanied by its larvae (r = 0.453, P < 0.05), while statistically significant negative correlation was obtained between egg abundance and temperature (r = −0.380, P < 0.05) as well as sea depth (r = −0.321, P < 0.05).

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