LIFE HISTORIES OF SOME COMMON SPIDERS FROM TREES AND SHRUBS IN NOVA SCOTIA

1961 ◽  
Vol 39 (6) ◽  
pp. 777-787 ◽  
Author(s):  
C. D. Dondale
Keyword(s):  
Nova Scotia ◽  
Life Histories ◽  
Carapace Width ◽  
Reproductive Maturity ◽  
Frequency Distributions ◽  
Two Generations ◽  
Trees And Shrubs

At Kentville, Nova Scotia, Araniella displicata (Hentz), Philodromus rufus Walckenaer, Philodromus cespiticolis Walckenaer, Paraphidippus marginatus (Walckenaer), and Metaphidippus protervus (Walckenaer) attained reproductive maturity in May and June. Eggs were laid in late June and early July. The young of A. displicata, P. rufus, and M. protervus began to appear in late July, while those of the remaining species began in early August. In A. displicata, P. rufus, P. cespiticolis, and P. marginatus there were two generations containing immature spiders at all times of the year, as indicated by frequency distributions of carapace width. It was concluded that these species are biennial in development. M. protervus, with only one generation containing immatures in any season, is annual.

scholarly journals Growth and population biology of the sand-bubbler crab Scopimera crabricauda Alcock 1900 (Brachyura: Dotillidae) from the Persian Gulf, Iran

2021 ◽  
Vol 82 (1) ◽  
Author(s):  
Sana Sharifian ◽  
Vahid Malekzadeh ◽  
Ehsan Kamrani ◽  
Mohsen Safaie
Keyword(s):  
Persian Gulf ◽  
Population Biology ◽  
Slow Growth ◽  
Carapace Width ◽  
Population Data ◽  
Natural Mortality ◽  
Frequency Distributions ◽  
Iranian Coast ◽  
The Mean ◽  
The Persian Gulf

Abstract Background Dotillid crabs are introduced as one common dwellers of sandy shores. We studied the ecology and growth of the sand bubbler crab Scopimera crabricauda Alcock, 1900, in the Persian Gulf, Iran. Crabs were sampled monthly by excavating nine quadrats at three intertidal levels during spring low tides from January 2016 to January 2017. Results Population data show unimodal size-frequency distributions in both sexes. The Von Bertalanffy function was calculated at CWt = 8.76 [1 − exp (− 0.56 (t + 0.39))], CWt = 7.90 [1 − exp (− 0.59 (t + 0.40))] and CWt = 9.35 [1 − exp (− 0.57 (t + 0.41))] for males, females, and both sexes, respectively. The life span appeared to be 5.35, 5.07, and 5.26 years for males, females, and both sexes, respectively. The cohorts were identified as two age continuous groups, with the mean model carapace width 5.39 and 7.11 mm for both sexes. The natural mortality (M) coefficients stood at 1.72 for males, 1.83 for females, and 1.76 years−1 for both sexes, respectively. The overall sex ratio (1:0.4) was significantly different from the expected 1:1 proportion with male-biased. Recruitment occurred with the highest number of annual pulse once a year during the summer. Conclusions The results, which show slow growth, emphasize the necessity of proper management for the survival of the stock of S. crabricauda on the Iranian coast of the Persian Gulf.

Reference points for the length-based indicator Lmax5% for use in the assessment of data-limited stocks

2019 ◽  
Vol 76 (7) ◽  
pp. 2125-2139 ◽  
Author(s):  
Tanja Miethe ◽  
Yves Reecht ◽  
Helen Dobby
Keyword(s):  
Life Histories ◽  
Stock Assessment ◽  
Reference Points ◽  
Length Frequency ◽  
Frequency Distributions ◽  
Simulation Tools ◽  
Spawning Potential Ratio ◽  
The Mean ◽  
Commercial Sources ◽  
Length Frequency Data

Abstract In the absence of abundance indices from scientific surveys or commercial sources, reliable length frequency data from sampled commercial catches can be used to provide an indirect assessment of fishing mortality. Length-based indicators are simple metrics which describe length frequency distributions. The length-based indicator Lmax5%, the mean length of the largest 5% of individuals in the catch, combined with appropriately selected reference points, can be used to evaluate the presence of very large individuals in the catch and hence determine exploitation level. Using analytical per-recruit models, we derive reference points consistent with a spawning potential ratio of 40%. The reference points depend on the life history parameters for natural mortality, maturity, and growth (M, Lmat, L∞, k, CVL∞). Using available simulation tools, we investigate the sensitivity of the reference points to errors in these parameters and explore the usefulness of particular reference points for management purposes for stocks with different life histories. The proposed reference points are robust to uncertainty in length at first capture, Lc, and take into account the maturation schedule of a species. For those stocks with high M/k ratios (>1), Lmax5%, combined with the appropriate reference point, can be used to provide a data-limited stock assessment.

STUDIES ON THE APOIDEA OF WESTERN NOVA SCOTIA WITH SPECIAL REFERENCE TO VISITORS TO APPLE BLOOM

1933 ◽  
Vol 9 (5) ◽  
pp. 443-457 ◽  
Author(s):  
C. E. Atwood
Keyword(s):  
Nova Scotia ◽  
Special Reference ◽  
Social Organization ◽  
Life Histories ◽  
Pupal Stage ◽  
Simple Type ◽  
Nest Construction ◽  
Wild Bees ◽  
Males And Females ◽  
Nova Scotian

This paper describes the results of studies on the wild bees of Nova Scotia, which were carried out in connection with apple pollination investigations in the Annapolis-Cornwallis Valley, Nova Scotia.The biology of the Apoidea in general is reviewed from the literature, and a list of bees taken on apple bloom is given. As the members of the genera Halictus and Andrena were found to be the most important native pollinators, the greater part of the paper is devoted to accounts of the habits and life histories of representative species.The members of the genus Andrena were found to have a simple type, such as is generally found among solitary bees. The females provision the nest and then die; the larvae develop to the pupal stage in their underground cells, then emerge as adults the following season. All Nova Scotian species studied were one-generation forms.The bees of the genus Halictus show a primitive social organization, more complex in some species than in others. The first brood consists of females only, which are apparently sterile and work at nest construction, the gathering of pollen, etc. They are followed later in the season by a brood of males and females; these females, after being fertilized, hibernate for the winter, while the males die in the fall. The hibernating habits of different species are described, and notes are given on some parasites and inquilines of the two genera.

REPEATED TRENDS OF FOLDS AND CROSS-FOLDS IN PALAEOZOIC ROCKS, PARRSBORO, NOVA SCOTIA

1964 ◽  
Vol 1 (3) ◽  
pp. 167-183 ◽  
Author(s):  
W. K. Fyson
Keyword(s):  
Nova Scotia ◽  
Vertical Movements ◽  
Clastic Rocks ◽  
Three Generations ◽  
The North ◽  
North Side ◽  
Two Generations ◽  
Major Fault ◽  
Granitic Intrusions ◽  
Middle Carboniferous

On the north side of a major fault three generations of folds F1, F2, F3 affect pre-Carboniferous phyllites; south of the fault two generations, C1, C2, affect middle Carboniferous clastic rocks. The F1 folds are isoclinal and obscure. The main folds, F2 in the phyllites and C1 in the Carboniferous rocks, trend east-northeast parallel to the fault. F2 are overturned southward and C1 northward, both toward the fault. Cross-folds, F3 in the phyllites and C2 in the Carboniferous rocks, trend northnortheast. Steeply plunging F3 and C2 are asymmetric and Z-shaped in plan profile.The F2 folds in the phyllites, though similar in geometry to folds in the middle Carboniferous rocks, appear, like F1 and F2, to have formed prior to the middle Carboniferous. This is indicated by the occurrence of unfolded Devonian(?) granitic intrusions crossing F3 folds, and a few miles north of the major fault, by middle Carboniferous rocks lying unconformably- above similar intrusions.One possible explanation for the repeated trends, which also accounts for the sense of overturning and asymmetry of the folds, relates the folding to alternating vertical and horizontal movements along the major fault. The vertical movements were followed by gravity sliding toward the fault to produce the main folds, and the horizontal movements, repeatedly dextral in sense, resulted in the Z-shaped cross-folds.

Integrated analysis of sexual maturation through successive growth instars in the spider crab Leurocyclus tuberculosus (Decapoda: Majoidea)

2017 ◽  
Vol 95 (7) ◽  
pp. 473-483 ◽  
Author(s):  
Ximena González-Pisani ◽  
Pedro J. Barón ◽  
Laura S. López Greco
Keyword(s):  
Sexual Maturation ◽  
Sexual Maturity ◽  
Carapace Width ◽  
Integrated Analysis ◽  
Growth Stages ◽  
Spider Crab ◽  
Size At Maturity ◽  
Frequency Distributions ◽  
The Right ◽  
Sexually Mature

An integrative analysis of sexual maturity associated with growth was developed for the spider crab Leurocyclus tuberculosus (H. Milne Edwards and Lucas, 1842). Sexual maturity was characterized based on gonadal, morphological, morphometric, and functional sexual maturity. Progress in sexual maturation was described through 13 growth stages (instars) detected by the examination of size (carapace width) frequency distributions. Mature females displayed mature ovaries, developed vaginae, open gonopores, allometric changes in the abdomen, and ovigerous stage in the transition from instar IX to instar X. Sexually mature males presented spermatophores in the distal vasa deferentia and allometric changes in several measurements of the right chela in the transition from instar X to instar XI. However, two prepubertal phases were recognized in both sexes separated from each other by a prepubertal critical molt. Preceding the second critical molt, gonopores were sealed and vasa deferentia showed no spermatophores, and therefore neither sex was able to mate. The integrated analysis of size at maturity and size frequency distributions showed that in both sexes molt to gonadal, morphological, morphometric, and functional sexual maturity occurred in advance of the terminal molt, in contrast with patterns observed in other Majoidea.

The Lobster (Homarus americanus) Fishery off Lower Argyle Southwestern Nova Scotia

1990 ◽  
Vol 47 (6) ◽  
pp. 1177-1184 ◽  
Author(s):  
Alan Campbell
Keyword(s):  
Nova Scotia ◽  
Fold Increase ◽  
Homarus Americanus ◽  
Weekly Basis ◽  
Index Numbers ◽  
Management Implications ◽  
Frequency Distributions ◽  
Fishing Season ◽  
Juvenile Abundance ◽  
Overall Mortality

Catch and effort data for the lobster (Homarus americanus) fishery of Lower Argyle, Nova Scotia, were obtained from sales slips on a weekly basis during 1978–87. Lobster size–frequency distributions were collected during at-sea sampling at the beginning and end of each fishing season. This fishery experienced a three-fold increase in landings (from 87.6 to 270 t) due to an increase in recruitment during the 10-yr study. The fishermen responded to the improved recruitment by increasing the total number of days fished per season by 41%. Overall mortality of recruited lobster (estimated from size–frequencies) rose from 55% in 1978 to 72–81% during 1985–87. During the 1987–88 fishing season, about 1 t lobster were removed per km2 of fishing grounds. Regression relationships between a prerecruit juvenile abundance index (numbers of lobster/trap haul) and the recruited yield one to two fishing seasons later were significantly correlated for 8–9 yr of data; equations predicted that lobster yields would remain high during the 1988–89 fishing season but decline in this area during 1989–90 fishing season. Management implications of forecasting recruitment yields 1–2 yr in advance and possible strategies to reduce major recruitment fluctuations in this fishery are discussed.

Overwintering Females and the Number of Generations of Typhlodromus (T.) pyri Scheuten (Acarina: Phytoseiidae) in Nova Scotia

1962 ◽  
Vol 94 (3) ◽  
pp. 233-242 ◽  
Author(s):  
H. J. Herbert
Keyword(s):  
Life History ◽  
Nova Scotia ◽  
Laboratory Study ◽  
Life Histories ◽  
Prey Species ◽  
Typhlodromus Pyri ◽  
Predacious Mite ◽  
Predominant Species ◽  
Laboratory Conditions ◽  
Wide Range

Typhlodromus pyri Scheuten (= T. tiliae Oudms.) is the predominant species of predacious mite on apples in Nova Scotia. It feeds on a wide range of prey species (Herbert, 1959). Chant (1960) investigated the life-history and habits of this species in southeastern England and Herbert (1956) studied its life-history under controlled laboratory conditions. A knowledge of the life-histories of various components of the fauna is basic to an evaluation of predation; therefore, a study of the life-history and habits of T. pyri in the field was undertaken. This was supplemented by a laboratory study in which an attempt was made to duplicate field temperarures. The results of these studies are presented here.

Fungi with heteroxenous life histories

1995 ◽  
Vol 73 (S1) ◽  
pp. 1334-1342 ◽  
Author(s):  
David Malloch
Keyword(s):  
Reproductive Success ◽  
Life Histories ◽  
Transmission Efficiency ◽  
Lifetime Reproductive Success ◽  
Population Densities ◽  
Frequency Distributions ◽  
Parasitic Fungi ◽  
Host Life ◽  
High Level ◽  
Dispersal Events

Heteroxenous (multiple host) life histories are characteristic of many groups of parasitic protista and animals, including Zoomastigina, Apicomplexa, Mesozoa, Platyhelminthes, Nematoda, Acanthocephala, Pentastomida, and Arthropoda. Parasitic fungi, including the Chytridiomycota and the Dikaryomycota (ascomycetes and basidiomycetes), may also have heteroxenous life histories and have many features in common with parasites from other groups. In spite of many conceptual similarities, the study of parasitic fungi has occurred in isolation, resulting in the creation of a separate vocabulary and literature. Many of the concepts developed by zoologists are useful to mycologists and allow examination of parasitic fungi from new perspectives. These new perspectives reveal that heteroxenous fungi are not only similar to heteroxenous protistans and animals but that they also have unique characteristics of their own. Chief among these is a high level of endocyclic asexual reproduction, a phenomenon promoting exponential increases of infections in definitive host populations. Heteroxeny appears to have a number of benefits including (i) increased lifetime reproductive success, (ii) increased transmission efficiency (iii) enhanced effectiveness in colonizing ephemeral or periodically appearing hosts and hosts occurring in low population densities, (iv) maintenance or enhancement of overdispersed frequency distributions in host populations, and (v) enhancement of genetic exchange through multiple dispersal events. Key words: fungi, heteroxenous, parasite, life histories.

OBSERVATIONS ON THE WHITE APPLE LEAFHOPPER, TYPHLOCYBA POMARIA (HEMIPTERA: CICADELLIDAE), AND ON THE MIRID PREDATOR BLEPHARIDOPTERUS ANGULATUS, AND MEASUREMENTS OF THEIR COLD-HARDINESS

1979 ◽  
Vol 111 (4) ◽  
pp. 487-490 ◽  
Author(s):  
A. W. MacPhee
Keyword(s):  
Nova Scotia ◽  
Low Temperatures ◽  
Cold Hardiness ◽  
Second Generation ◽  
Freezing Points ◽  
Two Generations ◽  
Predatory Mirid

AbstractTyphlocyba pomaria McA., with two generations per year, damages the leaves and defaces the fruit of apple. It was reduced in numbers in an experimental orchard by the predatory mirid Blepharidopterus angulatus (Fall.) which attacked the second generation. The cold-hardiness of T. pomaria and B. angulatus overwintering eggs, which had mean freezing points of −35 °C and −34 °C respectively, was sufficient to protect these species from winter low temperatures in Nova Scotia.

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