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Book ChapterDOI

Chapter 1 – INTRODUCTION: GENERAL PRINCIPLES

01 Jan 1974-pp 1-49
About: The article was published on 1974-01-01. It has received 290 citations till now.
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Book ChapterDOI
01 Jan 1983
TL;DR: The chapter discusses various physiological components of growth in marine molluscs (excluding the cephalopods) in relation to the major variables of body size, seasonal effects, temperature, oxygen concentration, and ration level.
Abstract: Publisher Summary This chapter discusses the physiological energetics of marine molluscs. The measurement of the components of the energy balance equation for individual organisms—namely, ingestion, absorption, excretion, and respiration—allows the derivation of the energy available to the animal for growth and for reproduction. In this way, it is possible to analyze the relationships between growth and various endogenous and exogenous variables in terms of underlying physiological processes. The chapter discusses various physiological components of growth in marine molluscs (excluding the cephalopods) in relation to the major variables of body size, seasonal effects, temperature, oxygen concentration, and ration level. Studies on energy flow at the population level indicate the average rates and efficiencies that have been reported in the major trophic categories. Three efficiencies of energy transfer are commonly considered: (1) absorption efficiency (A/C); (2) gross growth efficiency (P/C); and (3) net growth efficiency (P/A). The concept of scope for growth, which was regarded as the difference between the energy of the food an animal consumes and all other utilizations and losses, has descriptive validity for a wide range of environmental variables and has been widely used in the study of physiological adaptation in molluscs. Recent advances in knowledge of the population genetics of marine molluscs pose a challenge to the whole-animal physiologist, and future research in either discipline must clearly take account of recent understanding that derives from the other.

820 citations

Book ChapterDOI
Maria Byrne1
22 Jun 2011
TL;DR: To address questions of future vulnerabilities, data on the thermo- and pH/ pco2 tolerance of fertilization and development in marine invertebrates are reviewed in the context of the change in the oceans that are forecast to occur over the next 100-200 years.
Abstract: Global warming and increased atmospheric co2 are causing the oceans to warm, decrease in pH and become hypercapnic. These stressors have deleterious impacts on marine inver - tebrates. Increasing temperature has a pervasive stimulatory effect on metabolism until lethal levels are reached, whereas hypercapnia has a narcotic effect. ocean acidification is a major threat to cal - cifying larvae because it decreases availability of the carbonate ions required for skeletogenesis and also exerts a direct pH effect on physiology. Marine invertebrate propagules live in a multistressor world and climate change stressors are adding to the mix. ocean pH, pco2 and caco3 covary and will change simultaneously with temperature, challenging our ability to predict future outcomes for marine biota. To address questions of future vulnerabilities, data on the thermo- and pH/ pco2 tolerance of fertilization and development in marine invertebrates are reviewed in the context of the change in the oceans that are forecast to occur over the next 100-200 years. Gametes and fertilization in many invertebrates exhibit a broad tolerance to warming and acidification beyond stressor values projected for 2100. Available data show that all development stages are highly sensitive to warming. larvae may be particularly sensitive to acidification/hypercapnia. Embryos that develop through the bottleneck of mortality due to warming may succumb as larvae to acidification. Early juveniles may be vulnerable to skeletal dissolution, although warming may diminish the negative impact of acidifi - cation on calcification. The effects of climate change stressors and their interaction differ among life history stages and species. Multistressor experiments show that if thermal thresholds are breached, embryos may not reach the calcifying stage. If the bottleneck for species persistence is embryonic thermotolerance, then the question of compromised calicification due to acidification may not be relevant. our limited knowledge of the interactive effects of climate change stressors is a major knowledge gap. Although climate change is deleterious for development in a broad range of marine invertebrates, some species and regional faunas will be more resilient than others. This has implica- tions for persistence, faunal shifts, species invasions and community function in a changing ocean.

707 citations

Journal ArticleDOI
TL;DR: Systematic and biogeographical patterns in the reproductive biology of the Scleractinia are explored within the context of a new molecular phylogeny and using reproductive traits from nearly 400 species, confirming that coral sexuality is highly conserved, and mode of larval development is relatively plastic.
Abstract: A limited diversity of character states for reproductive traits and a robust phylogeny make scleractinian corals an ideal model organism with which to explore the evolution of life-history traits. Here, we explore systematic and biogeographical patterns in the reproductive biology of the Scleractinia within the context of a new molecular phylogeny and using reproductive traits from nearly 400 species. Our analyses confirm that coral sexuality is highly conserved, and mode of larval development is relatively plastic. An overabundance of species with autotrophic larvae in the eastern Pacific and Atlantic is most likely the result of increased capacity for long-distance dispersal conferred by vertical transmission of symbiotic zooxanthellae. Spawning records from diverse biogeographical regions indicate that multispecies spawning occurs in all speciose coral assemblages. A new quantitative index of spawning synchrony shows peaks at mid-tropical latitudes in the IndoPacific, influenced in part by two spawning seasons in many species on equatorial reefs.

645 citations

Journal ArticleDOI
TL;DR: The results indicate that production of zygotes could be much less than production of eggs, unless adults aggregate and spawn synchronously, countering dilution of sperm by currents.
Abstract: Percent fertilization of eggs of the echinoid Strongylocentrotus droebachiensis (O. F. Muller) was determined both in laboratory and field experiments. In the laboratory, over 50% of the eggs were fertilized only in relatively dense sperm suspensions (> 106 sperm/I); such suspensions retained their potency for less than 20 minutes. In the field, divers induced individual S. droebachiensis to spawn with KCl injections. Along five meter transects running directly downcurrent from spawning males, fixed volumes of seawater presumably containing sperm were drawn into syringes already containing eggs. Within 20 cm of spawning males 60-95% fertilization usually occurred; at distances greater than 20 cm less than 15% of the eggs were fertilized. Higher percentages of eggs were fertilized when current speeds were low (<0.2 m/s); swifter currents quickly diluted sperm so that little fertilization occurred. When several males were induced to spawn synchronously, percent fertilization increased but was generally less than 40% at distances greater than 2 m downstream. These results indicate that production of zygotes could be much less than production of eggs. Life-tables based on estimates of egg production may then be in error, unless adults aggregate and spawn synchronously, countering dilution of sperm by currents.

509 citations

Journal ArticleDOI
01 Oct 1990-Ophelia
TL;DR: Results from laboratory investigations suggest that mortality rates change with larval size or age, and theoretical exercises indicate that rates of larval mortality are correlated with duration of the planktonic period.
Abstract: Planktonic marine invertebrate embryos and larvae lead transitory lives of great risk and grave uncertainty. Estimation of the magnitude of risk and mortality, however presents a formidable challenge. Three methods are currently in use to estimate levels of mortality among populations of marine invertebrate larvae: 1) theoretical models where rates of instantaneous mortality are correlated with other life history parameters, 2) estimation of mortality based on laboratory observations of predator-prey interactions and 3) analysis of relationships among gamete production, larval populations, and densities of post-larvae in the field. Theoretical exercises indicate that rates of larval mortality are correlated with duration of the planktonic period, and that differences in mortality rates may be offset by differences in egg size and fecundity. Results from laboratory investigations suggest that mortality rates change with larval size or age. Attempts to monitor cohorts of larvae in the plankton offe...

480 citations

References
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Journal ArticleDOI
TL;DR: In analysing the ecological conditions of an animal population, the most sensitive stages within the life cycle of the animal are focused upon, that is, the period of breeding and larval development.
Abstract: 1. In analysing the ecological conditions of an animal population we have above all to focus our attention upon the most sensitive stages within the life cycle of the animal, that is, the period of breeding and larval development.

2,321 citations

Journal ArticleDOI
TL;DR: The literature is reviewed to show the conditions under which hermaphroditism may have evolved and it is concluded that all thee explanations have some validity.
Abstract: Possible selective advantages, including some new ones, for hermaphroditism are reviewed It is proposed that hermaphroditism should evolve under the following conditions: (a) where it is hard to find a mate; (b) where one sex benefits from being larger or smaller than the other; or (c) where there are small, genetically isolated populations Some conceptual problems and a comparative means of study are discussed The literature is reviewed to show the conditions under which hermaphroditism may have evolved It is concluded that all thee explanations have some validity

996 citations

Book
01 Jan 1964
TL;DR: Ostrea was given by Linnaeus (1758) to a number of mollusks which he described as follows: "Tethys, testa bivalvis inaequivalvis, subaurita. Vulva anusve nulius" as mentioned in this paper.
Abstract: NMg.-Approved tor Publi&la~ionApril 24, 1964. The family Ostreidae consists of a large number of edible and nonedible oysters. Their distribution is confined to a broad belt of coastal waters within the latitudes 64 0 N. and 44 0 S. With few exceptions oysters thrive in shallow water, their vertical distribution extending from a level approximately halfway between high and low tide levels to a depth of about 100 feet. Commercially exploited oyster beds are rarely found below a depth of 40 feet. The name "Ostrea" was given by Linnaeus (1758) to a number of mollusks which he described as follows: "Ostrea. Animal Tethys, testa bivalvis inaequivalvis, subaurita. Cardo edentulus and fossula cava ovata, striisque lateralibus transversis. Vulva anusve nulius." The name Tethys (from Greek mythology and also refers to the sea) applies to the type of marine animals, living either within the shells or naked, that Linnaeus listed under a general name "Vermes" which includes worms, mollusks, echinoderms, and others. The translation of Linnaeus' diagnosis reads as follows: SheH bivalve, unequal, almost ear-shaped. Hinge toothless, depression concave and oval-shaped, with transverse lines on the sides. No vulva or anus. TlUOoomlc characten • • ._•• _. _ Bhell. __ •• • •• ._•. _ Anatomy •" • • • • , _ sex and spawnlng••• _. • . __•• __ • ----_-_ Habitat. _.. • . ... .•__ . ••_. __ Larval shell (Prodlssoconch) _' _•• _._. • ' _ The genera of JIving oysters__ . •• ._••_. • ,_ •__ "_ Oimus Oatre4• • • __ • ._ • • __ ._._ -. _ Genns eruu__. ..__.. . . __ ._. .__ . ._. _ Oimas PrcnodorlU••_.__ •_-_ -_-_.-.-._ -__ ---_. --.., •__ . ---Bibliography • _. . • __ . __ ._ •__ • • _ PtJ4t

895 citations