scholarly journals The life history of weedy seadragons, Phyllopteryx taeniolatus (Teleostei:Syngnathidae)

2006 ◽  
Vol 57 (3) ◽  
pp. 313 ◽  
Author(s):  
Kristy L. Forsgren ◽  
Christopher G. Lowe
Keyword(s):  
Life History ◽  
Standard Length ◽  
Growth Parameters ◽  
Management Strategies ◽  
Morphological Characters ◽  
Mature Female ◽  
Von Bertalanffy ◽  
Population Demography ◽  
History Of

The aim of this study was to provide a detailed description of the life history of weedy seadragons, Phyllopteryx taeniolatus. Weedy seadragon development was described based on morphological characters and categorised into four periods: incubation, larval, juvenile and sub-adult. Hatching occurred 35–42 days post-fertilisation, most hatchlings exhibited juvenile characteristics upon hatching or shortly thereafter. The von Bertalanffy growth parameters generated from weedy seadragon length-at-age data were L ∞ = 285 ± 3 mm standard length (SL; mean ± s.e.) and k = 2.20 ± 0.05 year−1. Females possessed a higher gonosomatic index (GSI; 1.25 ± 1.18%; mean ± s.d.) than males (0.34 ± 0.20%), which increased substantially for females over 230 mm in length. Mature female weedy seadragons (290 ± 32 mm SL) ovulated 110 ± 27 eggs per female per spawning. Additionally, three females produced more than one clutch per season. Male weedy seadragons (319 ± 9 mm SL) successfully incubated 91 ± 40 eggs per spawning event. In addition to improving our understanding of the life history of weedy seadragons, this information can be used to estimate population demography and develop management strategies.

scholarly journals Age estimation, growth and maturity of the European hake (Merluccius merluccius (Linnaeus, 1758)) from Iberian Atlantic waters

2003 ◽  
Vol 60 (5) ◽  
pp. 1086-1102 ◽  
Author(s):  
C Piñeiro ◽  
M Saínza
Keyword(s):  
Life History ◽  
Age Estimation ◽  
Growth Parameters ◽  
Grey Literature ◽  
Von Bertalanffy ◽  
Merluccius Merluccius ◽  
Consistent Manner ◽  
The Mean ◽  
First Maturity ◽  
European Hake

Abstract Difficulties in age estimation for hake (Merluccius merluccius) have hampered the assessment of stocks. Here, we describe new, agreed ageing criteria based on the interpretation of the pattern of otolith growth. Improved estimates of von Bertalanffy growth parameters, and new estimates of maturity ogive parameters and length–weight relationships for European hake from Iberian Atlantic waters are presented. The results came from a study carried out during 1996–1997 and provide the first published account of the main life history traits of Southern stock hake. von Bertalanffy growth parameters of males were L∞ = 70cm, K = 0.18 year−1, and t0=−0.97 year, and those of females were L∞ = 89cm, K = 0.13 year−1, and t0 = −1.15 year. Growth of sexes differed from age 3 onwards, with females being on average larger and heavier than males. The estimated total length (L, cm)–total weight (W, g) relationships were W=0.0132135L2.8134246 for males and W=0.0086471L2.942563 for females. Spawning took place from December to May with a peak in February. The mean length and age at first maturity were 32.8 cm at 2.5 years for males and 45 cm at 4.4 years for females. Application of new ageing criteria showed that otolith sections may be used to determine ages up to 5 years in a consistent manner. These results indicate that hake of the Southern stock grow at higher rates and mature earlier than previously considered. Summaries of hake's life history parameters from other marine regions are also presented in order to make information that belongs largely to the grey literature available.

scholarly journals Age, growth and genetic status of the white shark (Carcharodon carcharias) from Kashima-nada, Japan

2011 ◽  
Vol 62 (6) ◽  
pp. 548 ◽  
Author(s):  
S. Tanaka ◽  
T. Kitamura ◽  
T. Mochizuki ◽  
K. Kofuji
Keyword(s):  
South Africa ◽  
Life History ◽  
Life History Traits ◽  
Growth Parameters ◽  
White Shark ◽  
Von Bertalanffy ◽  
Top Predator ◽  
Monophyletic Clade ◽  
Loop Region ◽  
D Loop

The white shark, a top predator inhabiting the world’s oceans, is an endangered species. However, knowledge of its life-history traits and population structure is still limited. We hypothesised that life-history traits would vary among populations because the species’ various habitats are diverse and change through time. Age was estimated by counting growth bands in the centra of white sharks caught in Japan. The von Bertalanffy growth parameters were estimated at L∞ = 455 cm TL, k = 0.196 year–1 and t0 = –1.92 years for males and L∞ = 607 cm TL, k = 0.159 year–1 and t0 = –1.80 years for females. The growth rate to maturity was higher than that known for individuals from California and South Africa. Male sharks matured at 310 cm TL at 4 years of age and females began to mature at ~450 cm TL and 7 years. The D-loop-region sequences of mitochondrial DNA extracted from Japanese white sharks and GenBank datasets from sharks of California, Australia, New Zealand and South Africa indicate that Japanese white sharks form a monophyletic clade separate from the populations of other regions. The results suggest that unique life-history traits of Japanese white sharks may be caused by genetic differences.

STUDIES ON CESTODES OF THE GENUS TRIAENOPHORUS FROM FISH OF LESSER SLAVE LAKE, ALBERTA: V. DESCRIPTION AND LIFE HISTORY OF TRIAENOPHORUS STIZOSTEDIONIS N.SP.

1945 ◽  
Vol 23d (5) ◽  
pp. 117-127 ◽  
Author(s):  
Richard B. Miller
Keyword(s):  
Life History ◽  
Male Genitalia ◽  
Sexual Maturity ◽  
Morphological Characters ◽  
Parietal Peritoneum ◽  
Stizostedion Vitreum ◽  
Pike Perch ◽  
History Of

Triaenophorus stizostedionis is a pseudophyllidean cestode that occurs as an adult in the intestine of the pike-perch, Stizostedion vitreum. It differs from T. crassus and T. nodulosus in several morphological characters but particularly in the shape of the scolex hooks and the size and disposition of the male genitalia. Sexual maturity is attained in the spring; spawning and death take place during the first two weeks of June. The eggs average 56 μ long by 40 μ wide. The coracidia average 73 by 71 μ. The procercoid develops in the copepod, Cyclops bicuspidatus, in from 10 days to two weeks. When fully grown it reaches 220 μ. The plerocercoids occur encysted on the visceral and parietal peritoneum of the trout-perch, Percopsis omiscomaycus. The life history is completed when an infested trout-perch is swallowed by a pike-perch.

scholarly journals Evolution of morphological and climatic adaptations inVeronica L.(Plantaginaceae)

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2333 ◽  
Author(s):  
Jian-Cheng Wang ◽  
Bo-Rong Pan ◽  
Dirk C. Albach
Keyword(s):  
Life History ◽  
Substitution Rate ◽  
Parallel Evolution ◽  
Morphological Characters ◽  
Annual Species ◽  
Selective Pressures ◽  
History Of ◽  
Phylogenetic Perspective ◽  
Drought Resistant ◽  
Annual Life History

Perennials and annuals apply different strategies to adapt to the adverse environment, based on ‘tolerance’ and ‘avoidance’, respectively. To understand lifespan evolution and its impact on plant adaptability, we carried out a comparative study of perennials and annuals in the genusVeronicafrom a phylogenetic perspective. The results showed that ancestors of the genusVeronicawere likely to be perennial plants. Annual life history ofVeronicahas evolved multiple times and subtrees with more annual species have a higher substitution rate. Annuals can adapt to more xeric habitats than perennials. This indicates that annuals are more drought-resistant than their perennial relatives. Due to adaptation to similar selective pressures, parallel evolution occurs in morphological characters among annual species ofVeronica.

scholarly journals Larval morphology and life history of Eutrichosoma mirabile Ashmead and description of a new species of Eutrichosoma (Hymenoptera, Chalcidoidea)

2020 ◽  
Vol 75 ◽  
pp. 67-85
Author(s):  
Austin J. Baker ◽  
John M. Heraty
Keyword(s):  
Life History ◽  
New Species ◽  
Morphological Characters ◽  
Larval Morphology ◽  
Phylogenetic Placement ◽  
History Of ◽  
A New Species

The larval morphology and life history of the weevil parasitoid Eutrichosoma mirabile Ashmead (Hymenoptera, Chalcidoidea, Pteromalidae) are described, and the phylogenetic placement of the subfamily Eutrichosomatinae within Chalcidoidea is determined using larval morphological characters. A description of Eutrichosoma burskisp. nov. and key to the species of Eutrichosoma are provided.

Revision of the Madagascan genera Oncodopus Brongniart and Colossopus Saussure (Orthoptera: Tettigoniidae: Conocephalinae; Euconchophorini), with description of Malagasopus gen. nov.

Zootaxa ◽  
2017 ◽  
Vol 4341 (2) ◽  
pp. 193 ◽  
Author(s):  
MUSTAFA ÜNAL ◽  
GEORGE W. BECCALONI
Keyword(s):  
Life History ◽  
New Species ◽  
Phylogenetic Relationships ◽  
New Genus ◽  
Habitat Preferences ◽  
Mate Guarding ◽  
Morphological Characters ◽  
Museum Specimens ◽  
History Of

The endemic Madagascan genera Oncodopus Brongniart and Colossopus Saussure are revised using museum specimens, including the types, and recently collected material. A new genus, Malagasopus gen. nov., and seven new species, Malagasopus desutterae sp. nov., Malagasopus meridianus sp. nov., Oncodopus janetae sp. nov., Oncodopus brongniarti sp. nov., Oncodopus saussurei sp. nov., Oncodopus soalalaensis sp. nov. and Colossopus parvicavus sp. nov. are described. Lectotypes are designated for Oncodopus zonatus Brongniart, 1897 and Colossopus redtenbacheri (Brongniart, 1897). A new term, mesothoracic auricle, is proposed for a structure on the episternum of the mesothorax. A tabulated key to the genera and keys to the species are presented. All species are described and diagnosed, and their phylogenetic relationships, geographical distributions, habitat preferences and phenologies are documented. The life history of Colossopus grandidieri is described, and the unusual possible mate-guarding behaviour of several species is discussed. Maps showing the distribution of the species are presented, as too are 57 photographs of museum specimens, 51 drawings of morphological characters, 17 photographs of living specimens and one habitat photograph. 

Life history of Lygus keltoni (Hemiptera: Miridae) in the laboratory

2006 ◽  
Vol 138 (6) ◽  
pp. 871-874 ◽  
Author(s):  
H.A. Cárcamo ◽  
T.R. Larson ◽  
C.E. Herle ◽  
J.K. Otani
Keyword(s):  
Life History ◽  
Management Strategies ◽  
Reproductive Potential ◽  
Adult Longevity ◽  
Western Canada ◽  
Life History Parameters ◽  
Egg Incubation ◽  
Preoviposition Period ◽  
Reproductive Life ◽  
History Of

AbstractLygus keltoni Schwartz and Foottit is a species of plant bugs recently recognized as distinct from L. shulli Knight and an important component of the pest complex that attacks a number of field crops such as canola (Brassica napus) and alfalfa (Medicago sativa) in western Canada. The current laboratory study was undertaken to determine basic life-history parameters, such as instar duration, adult longevity, and reproductive potential, required to develop biologically based pest management strategies. At 25–27 °C, males lived around 34 days and females lived around 48 days. Females produced an average of 133 nymphs but up to 306 nymphs during their reproductive life, which averaged around 4 weeks (7-day preoviposition period). Egg incubation lasted around 10 days, instars 1–4 lasted 2–3 days each, and the 5th instar lasted 4 days. The reproductive potential of L. keltoni seems to be lower than that of L. hesperus Knight and L. lineolaris (Palisot de Beauvois), but other life-history parameters of the adults and development times of the nymphs are comparable.

A new likelihood for simultaneously estimating von Bertalanffy growth parameters, gear selectivity, and natural and fishing mortality

2005 ◽  
Vol 62 (1) ◽  
pp. 215-223 ◽  
Author(s):  
Nathan G Taylor ◽  
Carl J Walters ◽  
Steven J.D. Martell
Keyword(s):  
Growth Parameters ◽  
Fork Length ◽  
Simulated Data ◽  
Data Sets ◽  
Von Bertalanffy ◽  
Fishing Mortality ◽  
Size Selectivity ◽  
Gear Selectivity ◽  
History Of ◽  
Size At Age

Gear selectivity and the cumulative effects of size-selective fishing produce bias in the length-at-age samples used to estimate the von Bertalanffy growth parameters. In fished populations, fast-growing young fish and slow-growing old fish are overrepresented in size–age samples. To account for such effects, we treated size-at-age observations as multinomial samples, with expected catches in each size–age category dependent on growth parameters, growth variation, size selectivity, abundance at age, and the history of exploitation. Using simulated data sets, estimated growth parameters using the multinomial likelihood were unbiased when fishing mortality was not too high and the shape of the vulnerability function was correct. In contrast, estimated growth parameters using a least squares approach overestimated the metabolic growth coefficient (K) and underestimated mean asymptotic length (L∞). Models that do not explicitly account for the effects of fishing and size selectivity underestimated L∞ and overestimated K. We estimate growth parameters for northern pikeminnow (Ptychocheilus oregonensis) as an example of the method and document a stunted "pigmy" population with an L∞ of 175-mm fork length, attributing its small size to effects of high density and (or) a short growing season.

scholarly journals Some explorations of the life history ratios to describe length composition, spawning-per-recruit, and the spawning potential ratio

2014 ◽  
Vol 72 (1) ◽  
pp. 204-216 ◽  
Author(s):  
Adrian Hordyk ◽  
Kotaro Ono ◽  
Keith Sainsbury ◽  
Neil Loneragan ◽  
Jeremy Prince
Keyword(s):  
Life History ◽  
Growth Parameters ◽  
Estimation Method ◽  
Cost Effective ◽  
Analytical Models ◽  
Small Scale ◽  
Natural Mortality ◽  
Von Bertalanffy ◽  
Cost Effective Method ◽  
Spawning Potential Ratio

Abstract Evaluating the status of data-poor fish stocks is often limited by incomplete knowledge of the basic life history parameters: the natural mortality rate (M), the von Bertalanffy growth parameters (L∞ and k), and the length at maturity (Lm). A common approach to estimate these individual parameters has been to use the Beverton–Holt life history invariants, the ratios M/k and Lm/L∞, especially for estimating M. In this study, we assumed no knowledge of the individual parameters, and explored how the information on life history strategy contained in these ratios can be applied to assessing data-poor stocks. We developed analytical models to develop a relationship between M/k and the von Bertalanffy growth curve, and demonstrate the link between the life history ratios and yield- and spawning-per-recruit. We further developed the previously recognized relationship between M/k and yield- and spawning-per-recruit by using information on Lm/L∞, knife-edge selectivity (Lc/L∞), and the ratio of fishing to natural mortality (F/M), to demonstrate the link between an exploited stock's expected length composition, and its spawning potential ratio (SPR), an internationally recognized measurement of stock status. Variation in length-at-age and logistic selectivity patterns were incorporated in the model to demonstrate how SPR can be calculated from the observed size composition of the catch; an advance which has potential as a cost-effective method for assessing data-poor stocks. A companion paper investigates the effects of deviations in the main assumptions of the model on the application of the analytical models developed in this study as a cost-effective method for stock assessment [Hordyk, A. R., Ono, K., Valencia, S., Loneragan, N. R., and Prince, J. D. 2015. A novel length based empirical estimation method of spawning potential ratio (SPR), and tests of its performance, for small-scale, data-poor fisheries. ICES Journal of Marine Science, 72: 217–231].

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