Population dynamics and reproduction of wild longsnout seahorse Hippocampus reidi

2011 ◽  
Vol 92 (2) ◽  
pp. 421-427 ◽  
Author(s):  
Ana C.G. Mai ◽  
Gonzalo Velasco
Keyword(s):  
Mature Female ◽  
Natural Mortality ◽  
Von Bertalanffy ◽  
Growth Constant ◽  
Instantaneous Rate ◽  
A Value ◽  
Eastern Brazil ◽  
North Eastern ◽  
Size At Sexual Maturity

Life-history characteristics such as growth, mortality, and size at sexual maturity of the seahorse Hippocampus reidi were investigated in situ in north-eastern Brazil from August 2006 to July 2007. The von Bertalanffy growth constant K was estimated at 1.195 year−1 and L∞ was set as 20 cm according to Taylor's relationship, using a Lmax of 19 cm. The smallest male with a brood pouch and the smallest male with a fully mature pouch measured 9 and 9.5 cm (height), respectively, while the smallest mature female measured 8.8 cm. Appropriate reproductive individuals were recorded throughout the study, with peaks from May to November. The size of first effective reproduction (carrying embryos) was 12.4 cm for males, a value higher than previously reported. Estimated instantaneous rate of natural mortality ranged from 1.43 to 1.58 year−1. The estimated life span for the species was 30 months.

scholarly journals Growth, mortality and length-weight relationship of the Bombay duck Harpadon nehereus (Ham. 1822) from North-eastern tip of the Bay of Bengal

2020 ◽  
Vol 32 (1) ◽  
pp. 135-139
Author(s):  
ROKEYA SULTANA ◽  
MD. ABDULLAH AL-MAMUN ◽  
ZOARDER FARUQUE AHMED ◽  
MST KANIZ FATEMA
Keyword(s):  
Growth Parameters ◽  
Natural Mortality ◽  
Von Bertalanffy ◽  
Growth Constant ◽  
North Eastern ◽  
Exploitation Rate ◽  
Bombay Duck ◽  
Relationship Of ◽  
Weight Data ◽  
Harpadon Nehereus

The present study was conducted to investigate the growth parameters, length-weight relationshipand diverse mortality rates of Bombay duck Harpadon nehereus, from North-eastern tip of the Bay of Bengal.The length weight data were collected from January to December 2017 where a total number of 2054individuals of both sex were analyzed. The von Bertalanffy growth parameters, the asymptotic length L?(cm), the growth constant K (year-1) and t0 were estimated as 38.50, 0.88, and -0.0181 years respectively.The growth performance index (Ø?) was found to be 3.115. The total length and body weight (L-W)relationship was found as W=0.004 L3.021, indicating that the growth rate showed a positive allometricpattern (b=3.021>3). The annual fishing morality rate (F) was 1.89, whereas the natural mortality rate (M)was 1.51. The obtained value of the exploitation rate (E= 0.56) indicated that the said population was inover-exploited condition.

Reproductive biology, age and growth of the two-banded seabream Diplodus vulgaris (Pisces: Sparidae) in the Gulf of Gabès, Tunisia

2013 ◽  
Vol 93 (5) ◽  
pp. 1415-1421 ◽  
Author(s):  
Aymen Hadj Taieb ◽  
Mohamed Ghorbel ◽  
Nader Ben Hadj Hamida ◽  
Othman Jarboui
Keyword(s):  
Growth Parameters ◽  
Age And Growth ◽  
Natural Mortality ◽  
Von Bertalanffy ◽  
Spawning Activity ◽  
Gulf Of Gabes ◽  
Instantaneous Rate ◽  
Total Length ◽  
Gulf Of Gabès ◽  
Overall Ratio

Samples of common two-banded seabream Diplodus vulgaris (N = 1097), used in this study, were caught in the Gulf of Gabès (Tunisia) from March 2008 to February 2010. Total length ranged from 7 to 25 cm. Diplodus vulgaris is a protandric hermaphrodite. The overall ratio of females to males was 1:1.66. The reproductive season extended from October to February, and the peak spawning activity occurred in December–January. The total length at which 50% of the population reached maturity was 14.14 ± 0.16 cm for females and 13.57 ± 0.01 cm for males. Parameters of the length–weight relationship (TW = aTLb) for all individuals were a = 0.0185 and b = 2.9319. The youngest specimen in this study was 0+ years, whereas the oldest one was 9 years. The von Bertalanffy growth parameters for the whole sample were: L∞ = 25.4 cm, k = 0.179 and t0 = −1.631 year. The instantaneous rate of natural mortality was: M = 0.333 year−1.

Age and growth of Alitta succinea (Polychaeta; Nereididae) in a tropical estuary of Brazil

2013 ◽  
Vol 93 (8) ◽  
pp. 2123-2128 ◽  
Author(s):  
C.S.C. Sette ◽  
R.A. Shinozaki-Mendes ◽  
T.L. Barros ◽  
J.R.B. Souza
Keyword(s):  
Growth Parameters ◽  
Length Distribution ◽  
Information Criteria ◽  
Age And Growth ◽  
Distribution Data ◽  
Tropical Estuary ◽  
Von Bertalanffy ◽  
Eastern Brazil ◽  
North Eastern ◽  
Shallow Subtidal

The aim of this work was to study the dynamics of Alitta succinea population growth in a tropical estuary. The organisms were collected in the polyhaline area of Pina Basin, north-eastern Brazil, in lower and shallow subtidal consolidated substrates, from October 2009 to March 2011. Fifteen samples with a size of 0.01 m2 were collected every month. A total of 2064 A. succinea individuals were measured for growth analysis, and the measure used was the length from prostomium to the 25th setiger. Growth parameters were estimated by the frequency–length distribution data from three different functions (i.e. von Bertalanffy, Gompertz and Richards). The differences in the densities of A. succinea were significant between the months of the dry and the rainy season, with the rain pattern being the factor that most affects the A. succinea life cycle. According to Akaike information criteria, the von Bertalanffy and Gompertz models were the ones that presented the best fit with the growth curve of A. succinea for the studied period. Using the Bhattacharya method for the analysis of modal progression, we identified eight cohorts. The lowest recruitment values were found in July and August 2010, respectively, and the remaining months had numbers of recruits that were representative of the total population. The growth performance index (Ø′) found was 2.86. The maximum longevity indicates that specimens of A. succinea live between 586 and 953 d, and the instantaneous mortality rate (Z) is 1.53 yr−1.

scholarly journals PERTUMBUHAN, MORTALITAS DAN TINGKAT PEMANFAATAN KERANG POKEA (Batissa violacea var. celebensis von Martens, 1897) DI SUNGAI LAEYA KONAWE SELATAN PROVINSI SULAWESI TENGGARA

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Sitti Nurlailah Basri ◽  
Bahtiar Bahtiar ◽  
La Anadi
Keyword(s):  
Growth Analysis ◽  
Total Mortality ◽  
Total Sample ◽  
Natural Mortality ◽  
Von Bertalanffy ◽  
Growth Constant ◽  
Area Method ◽  
Exploitation Rate ◽  
Model Inverse ◽  
Swept Area

Abstract : Pokea clam are one of the potential resources and have an important role both ecologically and economically. One of areas suitable for the life of this clam is the laeya river. This research aimed to determine growth, mortality and eksploitation rate of Pokea clam on the Laeya River in South Konawe which was started in September 2016 – February 2017. This research used swept area method by using a catching tool namely tangge. Data were growth, mortality and the exploitation level was analysed using Bhattacharya method, inverse von Bertalanffy, width converted catch curve and empirical Pauly, accommodated in FiSAT II version 3.0. The total sample of pokea clam during the research were 849 individuals. The result of growth analysis showed that the asymptotic width value (L∞), growth constant (K), estimated value t0 for the growth of pokea clam was 7,41, 0,56 and -0,38. The result of estimation analysis for the level of morality showed that the natural mortality value (M) was 1,84, the catching mortality (F) was 1,19, and the total mortality (Z) was 3,03. The exploitation rate (E) was 0,39 which shows the level exploitation rate of pokea clam in the waters of the Laeya River was still relatively low (under fishing). Keywords : Pokea Clam, Laeya Rivers, Growth, Mortality, Exploitation Rate Abstrak : Kerang pokea merupakan salah satu sumberdaya potensial dan mempunyai peranan penting baik secara ekologis maupun ekonomis. Salah satu wilayah yang cocok untuk kehidupan kerang ini adalah Sungai Laeya. Penelitian ini bertujuan untuk mengetahui pertumbuhan, mortalitas dan tingkat pemanfaatan kerang pokea di Sungai Laeya Konawe Selatan yang dimulai pada bulan September 2016 – Februari 2017. Metode penelitian yang digunakan adalah luas sapuan (swept area method) dengan memakai alat tangkap tangge. Data pertumbuhan, mortalitas dan tingkat eksploitasi masing-masing menggunakan metode Bhattacharya, model inverse von Bertalanffy, hasil tangkapan yang dikonversi dari data lebar cangkang dan empiris Pauly yang terakomodasi dalam program FiSAT II versi 3.0. Total sampel kerang pokea selama penelitian sebesar 849 individu. Hasil analisis pertumbuhan menunjukan nilai lebar asimtotik (L∞), konstanta pertumbuhan (K), nilai dugaan t0 pada pertumbuhan kerang pokea masing-masing 7,41, 0,56, dan -0,38. Hasil analisis pendugaan tingkat mortalitas menunjukkan nilai mortalitas alami (M) 1,84, mortalitas penangkapan (F) 1,19, dan mortalitas total (Z) 3,03. Tingkat eksploitasi (E) yaitu 0,39 yang menunjukkan tingkat eksploitasi kerang pokea di perairan Sungai Laeya masih tergolong rendah (under fishing). Kata Kunci : Kerang Pokea, Sungai Laeya, Pertumbuhan, Mortalitas, Tingkat Eksploitasi

Demography of the Agassiz's parrotfish Sparisoma frondosum (Agassiz, 1831) in north-eastern Brazil

2015 ◽  
Vol 96 (5) ◽  
pp. 1157-1166 ◽  
Author(s):  
Rosângela Lessa ◽  
Camila R. Da Silva ◽  
June F. Dias ◽  
Francisco M. Santana
Keyword(s):  
Growth Parameters ◽  
Growth Curves ◽  
Information Criterion ◽  
Age And Growth ◽  
Von Bertalanffy ◽  
Eastern Brazil ◽  
North Eastern ◽  
Marginal Increment ◽  
First Maturity ◽  
Size At First Maturity

Age and growth of Agassiz's parrotfish Sparisoma frondosum captured off Brazil (Pernambuco) were estimated using sagittal otoliths from 251 specimens. Sex of each specimen was determined and showed that 130 specimens were females (13.1 to 36.8 cm TL) and 121 were males (17.5 to 36.6 cm TL). The otolith marginal increment analysis indicated a single translucent ring formed every year. Parameters of growth curves were derived for the von Bertalanffy (VBGF) and Gompertz models. Based on the Akaike information criterion (AIC), both models were suitable for describing the growth of this species. VBGF parameters were estimated for males L∞ = 39.74 cm TL, K = 0.22, t0 = −1.63 years, females L∞ = 32.38 cm TL, K = 0.44; t0 = −0.23 years; and for the sexes combined L∞ = 33.66 cm TL, K = 0.41, t0 = −0.27 years. The study showed that 55% of individuals were 3 and 4 years of age, with maximal age of 9 years. Mature females (>17.6 cm TL) accounted for 45% of the sample. The age at first maturity for females was 1.6 years. For males the size at first maturity was not determined as immature individuals were not present in the overall sample. Also, primary males (PM) and specimens with gonads undergoing sexual transition were not found. The age structure and growth parameters for S. frondosum are an important contribution to the assessment of the state of exploitation of this species.

Taxonomy of Nystiellidae (Caenogastropoda, Epitonioidea) from Brazil, with description of three new species from the South-western Atlantic

2017 ◽  
Vol 98 (7) ◽  
pp. 1619-1644 ◽  
Author(s):  
Alexandre Dias Pimenta ◽  
Bruno Garcia Andrade ◽  
Ricardo Silva Absalão
Keyword(s):  
Rio Grande ◽  
Taxonomic Revision ◽  
South Atlantic ◽  
Shell Morphology ◽  
The South ◽  
Western Atlantic ◽  
North East ◽  
The North ◽  
Eastern Brazil ◽  
North Eastern

A taxonomic revision of the Nystiellidae from Brazil, including samples from the Rio Grande Rise, South Atlantic, was performed based on shell morphology. Five genera and 17 species were recognized. For the richest genus,Eccliseogyra, the three species previously recorded from Brazil were revised:E. brasiliensisandE. maracatu, previously known only from their respective type series, were re-examined. Newly available material ofE. maracatuexpanded the known geographic range of this species to off south-east Brazil.Eccliseogyra nitidais now recorded from north-eastern to south-eastern Brazil, as well as from the Rio Grande Rise. Three species ofEccliseogyraare newly recorded from the South Atlantic:E. monnioti, previously known from the north-eastern Atlantic, occurs off eastern Brazil and on the Rio Grande Rise; its protoconch is described for the first time, confirming its family allocation.Eccliseogyra pyrrhiasoccurs off eastern Brazil and on the Rio Grande Rise, andE. folinioff eastern Brazil. The genusIphitusis newly recorded from the South Atlantic.Iphitus robertsiwas found off northern Brazil, although the shells show some differences from the type material, with less-pronounced spiral keels. Additional new finds showed thatIphitus cancellatusranges from eastern Brazil to the Rio Grande Rise, and Iphitusnotiossp. nov. is restricted to the Rio Grande Rise.Narrimania, previously recorded from Brazil based on dubious records, is confirmed, including the only two living species described for the genus:N. azelotes, previously only known from the type locality in Florida, andN. concinna, previously known from the Mediterranean. A third species,Narrimania raquelaesp. nov. is described from eastern Brazil, diagnosed by its numerous and thinner cancellate sculpture. To the three species ofOpaliopsispreviously known from Brazil, a fourth species,O. arnaldoisp. nov., is added from eastern Brazil, and diagnosed by its very thin spiral sculpture, absence of a varix, and thinner microscopic parallel axial striae.Papuliscala nordestina, originally described from north-east Brazil, is recorded off eastern Brazil and synonymized withP. elongata, a species previously known only from the North Atlantic.

A Value Focused Thinking Approach to Decommissioning Decision Making

2021 ◽  
Author(s):  
Aaron Tung
Keyword(s):  
Decision Making ◽  
Scientific Evidence ◽  
Analysis Tool ◽  
Stakeholder Values ◽  
A Value ◽  
Value Focused Thinking ◽  
Science Theory ◽  
Past Experiences ◽  
Stakeholder Acceptance

Abstract Values are what stakeholders regard to be important to decisions (Kruglanski & Higgins 2007). How stakeholder prioritize, rank, balance, and trade-off values can have significant influence on their reasoning and evaluation of decommissioning outcomes and decisions. Stakeholder values can vary depending on various factors including religious beliefs, personal interests, and past experiences (Lechner et al., 2017). Value-focused thinking is a decision science theory developed by Keeney (1992) which builds upon the concept of varying stakeholder values. Keeney (1992) argues that the best decision is one that best reflects the actual values of stakeholders. which suggests that the acceptability of decommissioning decisions (full removal, partial removal, leave in-situ, rigs-to-reefs, etc.) by stakeholders will vary depending on the values of stakeholder in that particular context. This paper explores the idea of value-focused thinking and derive implications for decommissioning decision-making. Overall, the research finding suggests that rather than basing a decommissioning decision solely on scientific evidence, there is also a need for the decommissioning decisions to be able to reflect the actual values of stakeholders in that particular context. The criteria and weightage of the adopted multi-criteria decision analysis tool, for example, should accurately represent the actual values of stakeholders, so as to enable the tool to produce outcomes and decisions that has a higher probability of stakeholder acceptance.

scholarly journals Temporal and spatial patterns on serra, Scomberomorus brasiliensis (Teleostei, Scombridae), catches from the fisheries on the Maranhão coast, Brazil

2001 ◽  
Vol 61 (4) ◽  
pp. 541-546 ◽  
Author(s):  
V. da BATISTA ◽  
N. N. FABRÉ
Keyword(s):  
Spatial Patterns ◽  
Relative Abundance ◽  
West Coast ◽  
The West ◽  
Temporal And Spatial Patterns ◽  
Eastern Brazil ◽  
North Eastern ◽  
Displacement Pattern ◽  
Temporal And Spatial ◽  
Demersal Species

The displacement pattern of the serra, Scomberomorus brasiliensis, in North-eastern Brazil was analyzed from landing data recorded from the fleet fishing serra. Serra fishery has two seasons: from September to February (demersal species plus serra), and from March to August (almost only large amounts of serra). S. brasiliensis relative abundance increases similarly along the coast from March, but decreases first on the West coast from June. Records indicate that serra is near the coast at least until September/October in Eastern grounds. From October to March (strongest spawning season) there is no record of shoals on the coast. We concluded that the Maranhão coast is just a part of the migration circuit of S. brasiliensis that may exceed 300 nautical miles.

Sign in / Sign up

Export Citation Format

Share Document