Larvae and Pelagic Juveniles of Blackgill Rockfish, Sebastes melanostomus, Taken in Midwater Trawls off Southern California and Baja California

1978 ◽  
Vol 35 (7) ◽  
pp. 981-996 ◽  
Author(s):  
H. Geoffrey Moser ◽  
Elbert H. Ahlstrom
Keyword(s):  
Life History ◽  
Southern California ◽  
Baja California ◽  
Developmental Stages ◽  
Life History Strategy ◽  
The Body ◽  
Midwater Trawl ◽  
Life History Stages ◽  
Coastal Basins ◽  
Pelagic Juveniles

Examination of 217 midwater trawl samples from the coastal basins off southern California and Baja California revealed a recurring group of rockfish species. The late larvae and pelagic juveniles of the blackgill rockfish, Sebastes melanostomus, constituted 16% of the total number of rockfish specimens. The life-history stages of this species are described, with emphasis on the pelagic juvenile stage. Late stage larvae and pelagic juveniles develop a distinctive pattern of melanophore bands which, by disrupting the body outline, may help conceal the young during their midwater existence. Evidence from midwater trawl collections suggests that 30-mm pelagic juveniles migrate or are carried shoreward at a depth of ~ 200 m to the appropriate habitat for settling. The high relative abundance of blackgill rockfish pelagic juveniles in midwater trawl samples suggests that this species may represent a potential resource. Key words: blackgill rockfish, Sebastes melanostomus, larvae, pelagic juveniles, midwater trawls, developmental stages, melanophore patterns, life-history strategy, head-spine development

Language use, not language, is what develops in childhood and adolescence

2006 ◽  
Vol 29 (3) ◽  
pp. 280-281 ◽  
Author(s):  
Derek Bickerton
Keyword(s):  
Life History ◽  
Language Acquisition ◽  
Language Use ◽  
Developmental Stages ◽  
Language Evolution ◽  
Childhood And Adolescence ◽  
Life History Stages ◽  
Acquisition Period ◽  
Causative Factors

That both language and novel life-history stages are unique to humans is an interesting datum. But failure to distinguish between language and language use results in an exaggeration of the language acquisition period, which in turn vitiates claims that new developmental stages were causative factors in language evolution.

scholarly journals Live Fast, Die Young, and Sleep Later: Life History Strategy and Human Sleep Behavior

2020 ◽  
Author(s):  
Vahe Dishakjian ◽  
Daniel M T Fessler ◽  
Adam Maxwell Sparks
Keyword(s):  
Life History ◽  
Individual Differences ◽  
Sleep Duration ◽  
Sleep Onset ◽  
Life History Strategy ◽  
The Body ◽  
Equation Modeling ◽  
Sleep Onset Latency ◽  
Sleep Behaviors

Abstract Background and objectives Life History Theory (LHT) describes trade-offs that organisms make with regard to three investment pathways: growth, maintenance, and reproduction. In light of the reparative functions of sleep, we examine sleep behaviors and corresponding attitudes as proximate manifestations of an individual’s underlying relative prioritization of short-term reproduction versus long-term maintenance. Methodology We collected survey data from 568 participants across two online studies having different participant pools. We use a mixture of segmented and hierarchical regression models, structural equation modeling, and machine learning to infer relationships between sleep duration/quality, attitudes about sleep, and biodemographic/psychometric measures of life history strategy (LHS). Results An age-mediated U- or V-shaped relationship appears when LHS is plotted against habitual sleep duration, with the fastest strategies occupying the sections of the curve with the highest mortality risk: < 6.5 hours (short sleep) and > 8.5 hours (long sleep). LH “fastness” is associated with increased sleepiness and worse overall sleep quality: delayed sleep onset latency, more wakefulness after sleep onset, higher sleep-wake instability, and greater sleep duration variability. Hedonic valuations of sleep may mediate the effects of LHS on certain sleep parameters. Conclusions and implications The costs of deprioritizing maintenance can be parameterized in the domain of sleep, where “life history fastness” corresponds with sleep patterns associated with greater senescence and mortality. Individual differences in sleep having significant health implications can thus be understood as components of lifelong trajectories likely stemming from calibration to developmental circumstances. Relatedly, hedonic valuations of sleep may constitute useful avenues for non-pharmacological management of chronic sleep disorders. LAY Summary Sleep is essential because it allows the body to repair and maintain itself. But time spent sleeping is time that cannot be spent doing other things. People differ in how much they prioritize immediate rewards, including sociosexual opportunities, versus long-term goals. In this research, we show that individual differences in sleep behaviors, and attitudes toward sleep, correspond with psychological and behavioral differences reflecting such differing priorities. Orientation toward sleep can thus be understood as part of the overall lifetime strategies that people pursue.

scholarly journals Some Like It Hot: Evolution and Ecology of Novel Endosymbionts in Bat Flies of Cave-Roosting Bats (Hippoboscoidea, Nycterophiliinae)

2012 ◽  
Vol 78 (24) ◽  
pp. 8639-8649 ◽  
Author(s):  
Solon F. Morse ◽  
Carl W. Dick ◽  
Bruce D. Patterson ◽  
Katharina Dittmar
Keyword(s):  
Life History ◽  
Developmental Stages ◽  
Geographic Area ◽  
Pupal Development ◽  
Content Type ◽  
Environmental Tolerance ◽  
Temperature Range ◽  
Life History Stages ◽  
Bat Flies ◽  
Bacterial Endosymbionts

ABSTRACTWe investigated previously unknown associations between bacterial endosymbionts and bat flies of the subfamily Nycterophiliinae (Diptera, Streblidae). Molecular analyses revealed a novel clade ofGammaproteobacteriainNycterophiliabat flies. This clade was not closely related toArsenophonus-like microbes found in its sister genusPhalconomusand other bat flies. High population infection rates inNycterophiliaacross a wide geographic area, the presence of the symbionts in pupae, the general codivergence between hosts and symbionts, and high AT composition bias in symbiont genes together suggest that this host-symbiont association is obligate in nature and ancient in origin. SomeNycterophiliasamples (14.8%) also containedWolbachiasupergroup F (Alphaproteobacteria), suggesting a facultative symbiosis. Likelihood-based ancestral character mapping revealed that, initially, obligate symbionts exhibited association with host-specificNycterophiliabat flies that use a broad temperature range of cave environments for pupal development. As this mutualism evolved, the temperature range of bat flies narrowed to an exclusive use of hot caves, which was followed by a secondary broadening of the bat flies' host associations. These results suggest that the symbiosis has influenced the environmental tolerance of parasite life history stages. Furthermore, the contingent change to an expanded host range ofNycterophiliabat flies upon narrowing the ecological niche of their developmental stages suggests that altered environmental tolerance across life history stages may be a crucial factor in shaping parasite-host relationships.

The cells of Nephromyces: developmental stages of a single life cycle

1983 ◽  
Vol 61 (12) ◽  
pp. 3230-3239 ◽  
Author(s):  
Mary Beth Saffo ◽  
Rebecca Nelson
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Developmental Stages ◽  
Cell Types ◽  
Infective Stage ◽  
Microbial Infection ◽  
Microbial Cells ◽  
Life History Stages ◽  
Single Organism ◽  
Taxonomic Relations

Nephromyces Giard is a diverse collection of funguslike microbial cells, endosymbiotic in the ductless renal sac of molgulid ascidian tunicates (phylum Chordata). Though Giard considered Nephromyces a Chytridiomycete, the taxonomic affinities of these peculiar cells remain uncertain. In Molgula manhattensis DeKay, at least seven Nephromyces cell types can be distinguished. Despite their diverse appearance, these cell types are not separate taxa, but instead are separate life-history stages of a single organism. Developmental roles for these life-history stages are discussed, as are the possible taxonomic relations of Nephromyces. A new Nephromyces cell, a motile but nonflagellated infective stage, is described. The experiments reported here confirm earlier suggestions that the molgulid renal sac is not merely the site of an occasional or random microbial infection. Instead, this organ is the locus of an exclusive, presumably coevolved, association between two taxa: Nephromyces and the tunicate family Molgulidae.

Developmental shifts in functional morphology of the retina in Atlantic tarpon, Megalops atlanticus (Elopomorpha: Teleostei) between four ecologically distinct life-history stages

2010 ◽  
Vol 28 (4) ◽  
pp. 309-323 ◽  
Author(s):  
SCOTT M. TAYLOR ◽  
ELLIS. R. LOEW ◽  
MICHAEL S. GRACE
Keyword(s):  
Life History ◽  
Developmental Stages ◽  
Atlantic Coast ◽  
Piscivorous Fish ◽  
Life History Stages ◽  
Megalops Atlanticus ◽  
Transmission Electron ◽  
Stage Juvenile ◽  
And Behavior ◽  
Atlantic Tarpon

AbstractThe Atlantic tarpon, Megalops atlanticus, is a large piscivorous fish that supports economically important recreational fisheries in the Gulf of Mexico, Caribbean, and Florida Atlantic coast. Megalops atlanticus undergoes ontogenetic shifts in morphology, hatching in the open ocean as larvae (less than 1 cm in length), moving into hypoxic turbid mangrove marshes as juveniles (around 10 cm in length), and then moving into coastal oceanic waters as adults (over 100 cm in length). In this study, photoreceptor distributions, opsin distributions, and photoreceptor absorbance characteristics were studied with light microscopy, transmission electron microscopy, antiopsin immunofluorescence, and microspectrophotometry, respectively, at four ecologically distinct life-history stages—premetamorphic larva, settlement stage, juvenile, and adult. The purposes of this study were 1) to determine the extent to which the retina of M. atlanticus changes over the course of development and 2) to relate these retinal changes with ecological shifts between developmental stages. The new data presented here indicate that the M. atlanticus retina changes substantially in rod and cone distributions and absorbance characteristics over the course of development and that these changes correlate closely with those in habitat and behavior. We show that M. atlanticus has a rod-dominated retina at the larval stage (which is unusual for teleost larvae) and that the scotopic visual system becomes far better developed with maturity, adding a substantial tapetum and high densities of small, bundled, and stacked rod cells. We also show that there are shifts in cone and rod spectral sensitivities and an increase in the diversity of spectrally distinct cone classes, including the addition of ultraviolet cones as fish mature into adults.

Aspects of spatial and temporal cooccurrence in the life history stages of the sibling hakes, Urophycis chuss (Walbaum 1792) and Urophycis tenuis (Mitchill 1815) (Pisces: Gadidae)

1982 ◽  
Vol 60 (9) ◽  
pp. 2057-2078 ◽  
Author(s):  
Douglas F. Markle ◽  
David A. Methven ◽  
Linda J. Coates-Markle
Keyword(s):  
Young Adults ◽  
Life History ◽  
Sibling Species ◽  
Life Histories ◽  
Life History Strategy ◽  
Juvenile Stage ◽  
Life History Stage ◽  
Life History Stages ◽  
Delayed Maturation ◽  
The Right

The amount of coexistence in the sympatric sibling species, Urophycis chuss and U. tenuis, appears to be a function of ontogeny, with each life history stage showing different probabilities of interspecific encounters. Demersal juveniles coexist the least since U. chuss is inquiline with scallops and U. tenuis is in nearshore shallows. In U. tenuis there is also intraspecific segregation, with older juveniles and young adults bathymetrically segregated from the youngest demersal juveniles in summer.Relatively more coexistence is seen between neustonic juveniles. However, they show some seasonal and pronounced diel differences in availability to neuston nets (U. chuss predominates during the day and U. tenuis during night). The greatest coexistence is seen between adult U. chuss and adolescent to adult U. tenuis.Over its life, U. tenuis tends to move into deeper water while U. chuss is relatively stenotopic, its distribution largely a reaction to temperature. The life history strategy of U. tenuis is "get big quick," a goal achieved, in part, through delayed maturation (relative to U. chuss). The strategy of U. chuss seems to be avoid predation, concentrate growth in the juvenile stage, and "get mature quick." We speculate that both species' life histories may be subordinate to getting the demersal juveniles into the right nursery area at the right time.

scholarly journals How thermal ecophysiology assists the conservation of reptiles: case studies from New Zealand’s endemic fauna

2020 ◽  
pp. 269-286
Author(s):  
Alison Cree ◽  
Kelly M. Hare ◽  
Nicola J. Nelson ◽  
Christian Chukwuka ◽  
Jo Virens
Keyword(s):  
Life History ◽  
Case Studies ◽  
Environmental Temperature ◽  
The Body ◽  
Body Temperatures ◽  
Captive Management ◽  
Life History Stages ◽  
Physiological Processes

Environmental temperature profoundly influences the body temperatures of reptiles, and hence the rates at which physiological processes occur. We review progress in understanding the thermal ecophysiology of New Zealand’s endemic, terrestrial reptiles (tuatara, geckos, and skinks), and in applying this knowledge to conservation. By understanding the constraints and opportunities that environmental temperature places on different life-history stages, including embryos in nests and those that develop within live-bearing females, we can plan better translocations, improve captive management, and make stronger predictions about risks from changes in climate. We encourage conservation physiologists to offer leadership in demonstrating the societal transformations necessary to sustain a liveable planet.

scholarly journals Dynamic transcriptome and histomorphology analysis of developmental traits of hindlimb thigh muscle from Odorrana tormota and its adaptability to different life history stages

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Yilin Shu ◽  
Jun He ◽  
Huijuan Zhang ◽  
Guangxuan Liu ◽  
Shikun Li ◽  
...  
Keyword(s):  
Life History ◽  
Muscle Development ◽  
Developmental Stages ◽  
Thigh Muscle ◽  
Integrated Analysis ◽  
Life History Stages ◽  
Related Substances ◽  
Hindlimb Muscles ◽  
Muscle Groups ◽  
Developmental Traits

Abstract Background Systematic studies on the development and adaptation of hindlimb muscles in anura amphibians are rare. Here, we integrated analysis of transcriptome and histomorphological data for the hindlimb thigh muscle of Odorrana tormota (concave-eared torrent frog) at different developmental stages, to uncover the developmental traits of hindlimb thigh muscle from O. tormota and its adaptability to different life history stages. Results The development of hindlimb thigh muscle from O. tormota has the following characteristics. Before metamorphosis, myogenous cells proliferate and differentiate into myotubes, and form 11 muscle groups at G41; Primary myofibers and secondary myofibers appeared during metamorphosis; 11 muscle groups differentiated continuously to form myofibers, accompanied by myofibers hypertrophy after metamorphosis; During the growth process of O. tormota from G42 to G46, there were differences between the sexes in the muscle groups that differentiate into muscle fibers, indicating that there was sexual dimorphism in the hindlimb thigh muscles of O. tormota at the metamorphosis stages. Some genes and pathways related to growth, development, and movement ability of O. tormota at different developmental stages were obtained. In addition, some pathways associated with adaptation to metamorphosis and hibernation also were enriched. Furthermore, integrated analysis of the number of myofibers and transcriptome data suggested that myofibers of specific muscle groups in the hindlimbs may be degraded through lysosome and ubiquitin pathways to transform into energy metabolism and other energy-related substances to meet the physiological needs of hibernation. Conclusions These results provide further understanding the hindlimb thigh muscle development pattern of frogs and their adaption to life history stages.

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