Ontogenetic shifts in the distribution and reproductive patterns of Australian anchovy (Engraulis australis) determined by otolith microstructure analysis

2006 ◽  
Vol 57 (4) ◽  
pp. 373 ◽  
Author(s):  
W. F. Dimmlich ◽  
T. M. Ward
Keyword(s):  
Larval Survival ◽  
Ontogenetic Shifts ◽  
Larval Fishes ◽  
Wide Range ◽  
Otolith Increment ◽  
Otolith Microstructure Analysis ◽  
Survival And Growth ◽  
Age Studies ◽  
Eggs And Larvae ◽  
Behavioural Strategies

Upwelling systems can provide ideal conditions for survival and growth of larval fishes. However, these unstable environments are highly dispersive and mortalities can be high. Anchovies (Engraulis spp.) utilise a range of behavioural strategies to increase egg and larval survival. Ontogenetic shifts in distribution have been proposed for Australian anchovy (Engraulis australis), but no supporting otolith-based age studies have been published to date. The present study used otolith increment counts to age larval, juvenile and adult Australian anchovy, which spawn throughout South Australian gulf and shelf waters. Only fish up to 1 year of age occurred in the northern Spencer Gulf, where eggs and larvae in high densities are retained in a nursery area favourable to anchovies. The southern gulf area was inhabited by 1, 2 and 3 year olds. Older anchovy were found in offshore shelf waters, where upwelling occurs and larval survivorship may be high. We hypothesise that Australian anchovy move offshore with age to utilise the wide range of environments that provide suitable spawning and nursery areas for this species.

RELATIONSHIPS BETWEEN ATTACK RATES AND SURVIVAL OF WESTERN SPRUCE BUDWORM, CHORISTONEURA OCCIDENTALIS FREEMAN (LEPIDOPTERA: TORTRICIDAE), AND BUD DEVELOPMENT OF DOUGLAS-FIR, PSEUDOTSUGA MENZIESII (MIRB.) FRANCO

1992 ◽  
Vol 124 (2) ◽  
pp. 347-358 ◽  
Author(s):  
Roy F. Shepherd
Keyword(s):  
Close Association ◽  
Spruce Budworm ◽  
Larval Survival ◽  
Douglas Fir ◽  
Choristoneura Occidentalis ◽  
Western Spruce Budworm ◽  
Bud Development ◽  
Feeding Sites ◽  
Vegetative Buds ◽  
Wide Range

AbstractIndividual larvae of western spruce budworm (Choristoneura occidentalis Freeman) were observed from overwintering emergence to pupation at six locations spread over a wide range of altitudes and thus climate. A weekly census of 100 lower-crown buds per plot indicated large differences in rates of bud development and larval survival among locations.Emerging second-instar larvae attempted to mine swelling buds of Douglas-fir. If the buds were hard and tight, larvae mined 1-year-old needles until penetrable buds were available. Larvae dispersed over the crowns with only one larva becoming established in each bud; thus, many early-emerging and surplus larvae could not find suitable feeding sites and disappeared. Within the protective bud, survival was high. After buds flushed and larvae became exposed, densities dropped, probably due to increased predation and decreased food quality. Correlations indicated a close association between larval survival for the exposed period between bud flush and pupation, and overall larval survival.Douglas-fir trees responded to initial bud removal, but not to needle removal, by inducing latent buds in the axils of needles to grow into active vegetative buds ready to develop and flush the next spring. The number of these new vegetative buds formed was greatest when the initial buds were removed early in the season before flush, and decreased thereafter. Trees with vigorous crowns had the greatest response to defoliation by inducing the largest number of latent buds into becoming active vegetative buds; these were found mainly on the 2- and 3-year-old internodes.

Temporal patterns in distributions of tropical fish larvae on the North West Shelf of Australia

2004 ◽  
Vol 55 (5) ◽  
pp. 473 ◽  
Author(s):  
A. Sampey ◽  
M. G. Meekan ◽  
J. H. Carleton ◽  
A. D. McKinnon ◽  
M. I. McCormick
Keyword(s):  
Southern Oscillation ◽  
Fish Larvae ◽  
Early Stage ◽  
Larval Survival ◽  
Zooplankton Biomass ◽  
Tropical Fish ◽  
North West ◽  
Larval Fishes ◽  
The North ◽  
Abundance And Diversity

Information on the temporal distributions of tropical fish larvae is scarce. Early stage larval fishes were sampled using towed bongo plankton nets at sites on the southern North West Shelf of Australia (21°49′S, 114°14′E), between October and February of 1997/98 and 1998/99. The first summer was characterised by El Niño–Southern Oscillation-driven upwelling and high primary productivity, whereas in the second summer water temperatures were warmer and primary production was lower. Benthic percoid shorefishes dominated surface assemblages in both summers and this pattern may be typical of tropical shelf environments.The abundance and diversity of larval fishes were lowest in October and increased from November through to February. Assemblages displayed weak cross-shelf patterns, with a few taxa being more abundant at inshore sites (e.g. monacanthids), whereas others were more abundant offshore (e.g. scombrids). Although the composition of assemblages remained relatively consistent, many taxa (e.g. pomacentrids and carangids) showed differences in abundance between summers. Multivariate analyses found no relationships between abundance patterns of larval fishes and biophysical variables, such as temperature, salinity, and zooplankton biomass. Thus, seasonal changes in abundance may reflect differences in the spawning activities of adult fishes and/or larval survival.

scholarly journals Effects of Temperature on the Survival and Larval Development of Deiratonotus Japonicus (Brachyura, Camptandriidae) as a Biological Indicator

2020 ◽  
Vol 8 (3) ◽  
pp. 213 ◽  
Author(s):  
Il-Kweun Oh ◽  
Seung-Woo Lee
Keyword(s):  
Larval Development ◽  
Brachionus Plicatilis ◽  
Survival Rates ◽  
Biological Indicator ◽  
Larval Survival ◽  
Effect Of Temperature ◽  
Larval Stages ◽  
Kanagawa Prefecture ◽  
Survival And Growth ◽  
Increasing Temperature

Deiratonotus japonicus (D. japonicus) inhabits isolated locations and upstream brackish waters from Kanagawa Prefecture to Okinawa Prefecture in Japan. This species faces the threat of extinction because of changing habitat conditions. Our previous studies have shown that its complete larval development from hatching to metamorphosis consists of five zoeal stages and one megalopal stage. In this study, the effect of temperature on the survival and growth of larval development in D. japonicus under controlled laboratory conditions of 13, 18, 23, 24, 25, and 26 °C was investigated by rearing larvae (30 PSU; 12:12 h light/dark cycle; fed a diet of Brachionus plicatilis rotundiformis and Artemia sp. nauplii). The survival rates and developmental periods were measured for each larval stage. The highest survival rates were obtained at 18–24 °C. Metamorphosis to megalopa occurred at 23–25 °C. There were rapid and synchronous developments at 25–26 °C but delayed and extended developments at 13 °C. The molting period decreased with increasing temperature. With decreasing temperature, the beginning of the development and duration of molting was prolonged. In addition, there were very low survival rates at 13 °C and 26 °C in all zoeal stages. Our results indicate that the early larval stages of D. japonicus are well adapted to 18–24 °C, the range observed in the estuarine marine environment of the Kita River during the breeding season. Optimum larval survival and growth were obtained at 23 °C. Temperature significantly affected the survival rate, developmental period, and molting of the larvae. The relationship between the cumulative periods of development from hatching through individual larval stages (y) and temperatures (T) was described as a power function (y = a × Tb).

The use of harpacticoid copepods as live prey for Amphiprion clarkii larviculture: Effects on larval survival and growth

Aquaculture ◽  
2008 ◽  
Vol 274 (2-4) ◽  
pp. 347-352 ◽  
Author(s):  
I. Olivotto ◽  
F. Capriotti ◽  
I. Buttino ◽  
A.M. Avella ◽  
V. Vitiello ◽  
...  
Keyword(s):  
Larval Survival ◽  
Live Prey ◽  
Harpacticoid Copepods ◽  
Survival And Growth ◽  
Amphiprion Clarkii

scholarly journals Coral larvae for restoration and research: a large-scale method for rearing Acropora millepora larvae, inducing settlement, and establishing symbiosis

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3732 ◽  
Author(s):  
F. Joseph Pollock ◽  
Sefano M. Katz ◽  
Jeroen A.J.M. van de Water ◽  
Sarah W. Davies ◽  
Margaux Hein ◽  
...  
Keyword(s):  
Large Scale ◽  
Larval Settlement ◽  
Larval Survival ◽  
Coralline Algae ◽  
Larval Rearing ◽  
Crustose Coralline Algae ◽  
Minimal Impact ◽  
Acropora Millepora ◽  
Wide Range ◽  
Order Of Magnitude

Here we describe an efficient and effective technique for rearing sexually-derived coral propagules from spawning through larval settlement and symbiont uptake with minimal impact on natural coral populations. We sought to maximize larval survival while minimizing expense and daily husbandry maintenance by experimentally determining optimized conditions and protocols for gamete fertilization, larval cultivation, induction of larval settlement by crustose coralline algae, and inoculation of newly settled juveniles with their dinoflagellate symbiont Symbiodinium. Larval rearing densities at or below 0.2 larvae mL−1 were found to maximize larval survival and settlement success in culture tanks while minimizing maintenance effort. Induction of larval settlement via the addition of a ground mixture of diverse crustose coralline algae (CCA) is recommended, given the challenging nature of in situ CCA identification and our finding that non settlement-inducing CCA assemblages do not inhibit larval settlement if suitable assemblages are present. Although order of magnitude differences in infectivity were found between common Great Barrier Reef Symbiodinium clades C and D, no significant differences in Symbiodinium uptake were observed between laboratory-cultured and wild-harvested symbionts in each case. The technique presented here for Acropora millepora can be adapted for research and restoration efforts in a wide range of broadcast spawning coral species.

Terapia di gruppo: il setting gruppale nel trattamento delle dipendenze

MISSION ◽  
2019 ◽  
pp. 51-59
Author(s):  
Pietro Algisi
Keyword(s):  
Substance Abuse ◽  
Group Intervention ◽  
Welfare System ◽  
Positive Outcomes ◽  
Specific Field ◽  
Addiction Therapy ◽  
Number Of Patients ◽  
Wide Range ◽  
Hospital Team ◽  
Behavioural Strategies

The development and maturation of group intervention techniques have conferred more and more to grouptherapy the characteristics of an effective intervention technique on many pathologies and from the ‘70s therehas been a progressive application of this technique to the specific field of addiction therapy with a growing consensusby specialists for the positive outcomes supported by scientific literature.Also in Italy, the use of this work tool is a reality that is characterizing more and more the practice in differentclinical areas of addiction and group intervention has become one of the main therapeutic resources of outpatientand hospital team for the wide range of possible strategies and for the high number of patients that is possibleto treat effectively, combining the criteria of efficacy and of efficiency.This article highlights the specific processes and dynamics of psychodynamic oriented psychotherapeutic grouptreatment, which aims to develop a better self-protective ability not only trough the identification and experimentationof new psyco-behavioural strategies different from the dysfunctional ones of substance abuse but alsotrough the acquisition of instruments and resources to find your own "welfare system", affective, emotional,physic and mental, and to try to keep it in balance as much as possible

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