Reproductive success, relative abundance and population structure of two species of Nephtys in an estuarine beach

Olive, P. J. W.; Garwood, P. R.; Bentley, M. G.; Wright, N.

doi:10.1007/bf00406827

Cited by 33 publications

(23 citation statements)

References 15 publications

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“…N. virens juveniles are sliders. BeUan (1977) and Olive et al (1981) reported higher densities of N. caeca in sandy (> 50%) regions, as appears to be the case for the majority of nephtyids (Olive et al 1985). The major reason for the high density of juveniles in the high shore zone is, however, likely to be their detritivorous feeding habit and a subsequent requirement for fine sediments (Bloom et al 1972).…”

Section: Discussionmentioning

confidence: 97%

“…Its requirements for coarse sediment further favors its limitation to homogeneously sandy zones (Bellan 1977). Nevertheless, migration could be initiated by decreases in food level or by canibalism, and thereby have some adaptive value (Olive et al 1981). Warwick and Price reported a sublittoral larval settlement and subsequent onshore migration for N. hombergi.…”

Section: Discussionmentioning

confidence: 99%

“…Warwick and Price reported a sublittoral larval settlement and subsequent onshore migration for N. hombergi. Nephtyids may therefore occupy habitats where conditions for reproduction are not optimal every year (Olive et al 1981(Olive et al , 1985. A migration triggered by changing food requirements similar to that ofNereis virens would thus not seem possible.…”

Section: Discussionmentioning

confidence: 99%

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Distributions and population structures of two intertidal estuarine polychaetes in the lower St. Lawrence Estuary, with special reference to environmental factors

Miron

Desrosiers

1990

Mar. Biol.

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An intensive study of the spatial distribution of Nereis virens (Sars) and Nephtys caeca (Fabricius) was conducted during the spring and autumn of 1986 in the lower St. Lawrence estuary. Statistical analysis showed that spatial variations in density, individual body weight and sexual maturity, particularly in the case of Nereis virens, are correlated with the intertidal level, with certain sediment characteristics, and with the thickness of the colonizable sediment layer. The density of N. virens increases in an offshore-onshore direction, whereas that of Nephtys caeca decreases in the same direction. For both species, mean body weight increases downshore from the upper intertidal level. Other specific relationships exist in relation to sediment characteristics. Sexually mature Nereis virens are found only at the lower intertidal level; sexual maturity in Nephtys caeca was not studied. There were no changes in spatial distribution patterns between spring and autumn. The spatial distribution of Nereis virens parallels depth contours and may reflect its ability to inhabit environments which become more physically unstable in an offshore-onshore direction. This spatial distribution is consistent with a model whereby larvae are recruited in the upper intertidal zone and juveniles migrate downshore.

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Section: Discussionmentioning

confidence: 97%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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Distributions and population structures of two intertidal estuarine polychaetes in the lower St. Lawrence Estuary, with special reference to environmental factors

Miron

Desrosiers

1990

Mar. Biol.

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“…High longevity (a life-span of more than 5 years), small eggs, and planktotrophic development are common to all the species. Therefore, Nephtyidae may be regarded as K-selected organisms (Olive 1984b) However, there is considerable variation in the reproductive output of individual species among field localities and among years, even in the same niche (Olive et al 1981b(Olive et al , 1997. The characteristics of energy allocation to reproduction also vary among species, the annual reproductive index for N. hombergi and Nephtys coeca being 0.33 and 0.24, respectively (Olive et al 1997).…”

Section: The Reproductive Cycle Of Nephtys Hombergi (Nephtyidae)mentioning

confidence: 98%

Endocrine and environmental control of reproduction in Polychaeta

Andries¹

2001

Can. J. Zool.

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In Polychaeta, as in many invertebrates, reproduction is controlled by both environmental and endocrine factors. Although the effects of environmental factors on reproductive behaviour are briefly discussed, this review focuses on the endocrinology of reproduction. As Nereidae are the most intensively studied polychaetes, their epigamic monotelic strategy is discussed first in this review. Although a large number of physiological observations have been made, biochemical data have been greatly lacking until recent years, except, however, for the recent isolation of several pheromones. These substances, such as uric acid and L-cysteine gluthathione disulfide, occur widely and must be present at high concentrations in order to exert their physiological effects. Results obtained from iteroparous species are also considered. The stolonization strategy of Syllidae, the control of vitellogenesis in Nephtyidae, Phyllodocidae, Polynoidae, and Cirratulidae, and the regulation of gamete maturation in Arenicolidae and Pectinariidae are discussed. As with Nereidae, our knowledge of endocrine control is mainly based on experimental data, since only spermmaturation factor in the genus Arenicola has been identified. Therefore, despite numerous interesting experimental studies in which functional roles for polychaete reproductive hormones have been described, their nature, their primary targets, and their mechanism of action are unfortunately still largely unknown.Résumé : Chez les polychètes, comme chez de nombreux invertébrés, la reproduction est sous le contrôle de facteurs de l'environnement et de facteurs endocriniens. L'objet essentiel de cette synthèse est le contrôle endocrinien de la reproduction; des données plus fragmentaires ont trait aux effets des facteurs environnementaux. Puisque les Nereidae sont les polychètes les mieux connus, l'étude de leur stratégie monotélique épigame est envisagée dans un premier point. Toutefois, malgré de nombreuses observations physiologiques, peu de données biochimiques sont disponibles, si l'on excepte l'isolement récent de plusieurs phéromones. Celles-ci, comme l'acide urique et le disulfure de L-cystéine glutathion, sont des substances ubiquistes qui, de ce fait, doivent être présentes en concentrations élevées afin de pouvoir exercer une action physiologique. Les résultats obtenus chez les espèces itéropares font l'objet d'un second point. La stratégie de stolonisation des Syllidae, le contrôle de la vitellogenèse des Nephtyidae, des Phyllodocidae, des Polynoidae et des Cirratulidae, ainsi que le contrôle de la maturation des gamètes des Arenicolidae et des Pectinariidae sont examinés. Comme dans le cas des Nereidae, notre compréhension du contrôle endocrinien repose essentiellement sur des données expérimentales. Seul est identifié le facteur de maturation des spermatozoïdes d'Arenicola. Ainsi, malgré les nombreuses études expérimentales réalisées chez les polychètes et les multiples actions hormonales décrites dans les processus de reproduction, la nature des hormones, leurs cibl...

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“…hombergi begins with the production of primary oocytes around the capillaries of the genital blood vessels. Usually, the ovary at this time, contains a number of oocytes well into oogenesis and at almost full size, as a result of incomplete spawning of the previous year's cohort of oocytes in the spring (Olive et al, 1981a;Olive et al, 1981b;Olive et al, 1985). Whilst most unspawned oocytes are resorbed, it may be that some of these oocytes will remain in the ovary throughout the next phase of gametogenesis and be spawned in the following April or May.…”

Section: Introductionmentioning

confidence: 99%

An ultrastructural study of oogenesis in the polychaeteNephtys hombergi Savigny

Bentley

1989

Helgolander Meeresunters

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The polychaete Nephtys hombergi has an annual cycle of reproduction. Ovaries were fixed for electron microscopy during the gametogenic phase from September to March, and during the breeding and post-breeding period. Oogenesis takes place entirely within the ovary, the integrity of which is maintained by a network of simple follicle cells. Previtellogenic oocytes have close contacts with the peri-vasal cells which surround the genital blood capillaries. These contacts are lost as the oocytes enter vitellogenesis. The vitellogenic oocytes have a cytology typical of oocytes which are thought to undergo autosynthetic production of protein yolk. Biochemical studies would be required to establish whether heterosynthesis of yolk also occurs. As the oocytes proceed through vitellogenesis, cortical material is laid down near the periphery of the oocyte and a microvillous surface is developed. When the microvillous surface is complete the oocytes, by then hormone independent, are ovulated from the ovary and are ready to be spawned.

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Reproductive success, relative abundance and population structure of two species of Nephtys in an estuarine beach

Cited by 33 publications

References 15 publications

Distributions and population structures of two intertidal estuarine polychaetes in the lower St. Lawrence Estuary, with special reference to environmental factors

Distributions and population structures of two intertidal estuarine polychaetes in the lower St. Lawrence Estuary, with special reference to environmental factors

Endocrine and environmental control of reproduction in Polychaeta

An ultrastructural study of oogenesis in the polychaeteNephtys hombergi Savigny

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