Growth and population structure of the seabob shrimp Xiphopenaeus kroyeri (Decapoda: Penaeidae) on the continental shelf of Sergipe, Brazil

2018 ◽  
Vol 99 (1) ◽  
pp. 81-92 ◽  
Author(s):  
Sonja Luana Rezende Da Silva ◽  
Rafael De Carvalho Santos ◽  
Rogério Caetano Costa ◽  
Gustavo Luis Hirose
Keyword(s):  
Population Structure ◽  
Sex Ratio ◽  
Sexual Maturity ◽  
Growth Parameters ◽  
Logistic Function ◽  
Individual Growth ◽  
Brazilian Coast ◽  
Chi Square ◽  
Shrimp Fishery ◽  
Xiphopenaeus Kroyeri

This study evaluated the population structure, growth and longevity of Xiphopenaeus kroyeri in the State of Sergipe. The obtained data were compared with other populations on a latitudinal scale in order to evaluate whether the latitudinal paradigm applies to this species. Shrimp sampling took place monthly from September 2013 to August 2014, in nine stations distributed at 5, 15 and 30 m depths, using a shrimp fishery boat equipped with a ‘double rig’ net. Sexual maturity was estimated by the logistic function y = a/(1 + b*exp(-cx)), and the sex ratio was analysed with the Chi-square test. The individual growth rate was estimated using the von Bertalanffy model, and the longevity was estimated by the inverse form of this formula. A total of 6418 (3457 females and 2961 males) was analysed. The size at onset of sexual maturity was 12 mm of carapace length (CL) for males and 12.5 mm CL for females. The total sex ratio did not differ from the expected (1:1). Males exhibited higher growth coefficients (k) and smaller asymptotic growth (CC∞ = 28.74 mm, k = 0.0081 day−1) than females (CC∞ = 30.79 mm, k = 0.0058 day−1). The estimated longevity (years) was 1.55 for males and 2.15 for females. No evident latitudinal pattern was observed regarding the size at onset of sexual maturity or the growth parameters for X. kroyeri. The information found, besides contributing to the knowledge about the biology of this shrimp, can also clarify hypotheses presented in relation to the latitudinal paradigm along the Brazilian coast.

scholarly journals Population structure and reproductive characteristics of the silky shark Carcharhinus falciformis (Müller & Henle, 1839) (Carcharhiniformes: Carcharhinidae) off the coast of Oaxaca, Mexico

2017 ◽  
Vol 44 (3) ◽  
pp. 513-524
Author(s):  
María del Carmen Alejo-Plata ◽  
Miguel Ángel Ahumada-Sempoal ◽  
José Luis Gómez-Márquez ◽  
Adrián González-Acosta
Keyword(s):  
Population Structure ◽  
Sex Ratio ◽  
Seasonal Changes ◽  
Sexual Maturity ◽  
Size Structure ◽  
Landing Sites ◽  
Silky Shark ◽  
Oceanic Species ◽  
Carcharhinus Falciformis ◽  
Gravid Females

Carcharhinus falciformis is an abundant oceanic species, which occurs in equatorial and tropical zones, with an important catch in the Atlantic and Pacific coasts of Mexico. Samples were taken from December 2000 to December 2007 in four landing sites of the artisanal fleet on the coast of Oaxaca. During the period of study 1236 specimens (602 females and 634 males) of C. falciformis were registered. Total length (TL) ranged from 49 to 217 cm for females (mean = 111.3 cm) and from 59 to 265 cm for males (mean = 111.7 cm). The sex ratio of females to males was 1:1 ( 2 0.05 = 0.78, P > 0.05). The present data suggest a size at first sexual maturity of about 184.8 cm TL for females and 178.5 cm TL for males. The catches were composed mainly of young. In the 52 gravid females examined, the average number of embryos per female was seven; with a range of 3-14 embryos. Mean TL of embryos ranged from 10 to 66 cm with evidence of seasonal changes in the size structure. Results obtained showed that C. falciformis gives birth most of the year, with the highest proportion of births during the rainy season (May to October).

Brook Trout (Salvelinus fontinalis) Population Structure in Acidified Lac Tantaré, Quebec

1984 ◽  
Vol 41 (6) ◽  
pp. 865-877 ◽  
Author(s):  
Jean-Jacques Frenette ◽  
Julian J. Dodson
Keyword(s):  
Population Structure ◽  
Brook Trout ◽  
Sexual Maturity ◽  
Reproductive Effort ◽  
Salvelinus Fontinalis ◽  
Individual Growth ◽  
Toxic Stress ◽  
Age Classes ◽  
Recruitment Failure ◽  
Trout Population

To present evidence of acid-induced stress, we studied the population structure and distribution of brook trout (Salvelinus fontinalis) in acidified Lac Tantaré, Quebec. Trout greater than 21 cm (FL) represented only 16.2 and 10% of the population sampled in 1979 and 1980, respectively. Survival rates of trout from 1979 to 1980 indicated higher survival among individuals > 25 cm, mortality occurring primarily among fish of 13–25 cm. The marked decline in numbers of fish occurring at 21 cm coincided with the size at which 50% of the female trout population reached sexual maturity, suggesting that postspawning mortality contributes to the high mortality observed among these fish. Comparisons of population and individual growth rates revealed that smaller fish of age-classes 1 to 5 suffer higher mortality than do the larger individuals of these age-classes, implicating mortality agents other than those related to spawning. We provide evidence to support the hypothesis that the most probable cause of mortality is size-related differential exposure to toxic stress whereby small brook trout (< 25 cm) are found in lake areas (brooks) exhibiting the most potentially toxic combination of pH and aluminum, thus enhancing the exposure of the most susceptible part of the population to toxic stress. Large brook trout [Formula: see text] are found in the "safest" lake areas (springs), thus diminishing the exposure of the least susceptible part of the population to toxic stress and enhancing survival. Female trout exhibit delayed sexual maturity relative to other Quebec populations, attaining 50% maturity at age 3 and a length of 21–24 cm such that the major part of the population's reproductive effort is provided by those fish representing only 15% of the population in 1979 and 1980. During the October spawning season, 20% of potential spawners exhibited retarded oogenesis. These reductions in reproductive effort and changes in spawning site selection provide evidence in support of the hypothesis that recruitment failure may be occurring in the Tantaré brook trout population.

scholarly journals ASPEK BIOLOGI IKAN TEMBANG (Sardinella gibbosa BLEEKER, 1849) DI PERAIRAN PRIGI DAN SEKITARNYA

2019 ◽  
Vol 11 (3) ◽  
pp. 151
Author(s):  
Prawira A. R. P. Tampubolon ◽  
Maya Agustina ◽  
Zulkarnaen Fahmi
Keyword(s):  
Sex Ratio ◽  
Logistic Function ◽  
Purse Seine ◽  
Chi Square ◽  
Gonadal Maturity ◽  
Fish Samples ◽  
Sardinella Gibbosa ◽  
Chi Square Test ◽  
Relationship Of ◽  
The Relationship

Ikan tembang (Sardinella gibbosa Bleeker, 1849) adalah salah satu jenis ikan pelagis kecil, bernilai ekonomis penting serta banyak tertangkap di perairan Prigi dan sekitarnya. Informasi terkait ikan ini masih sangat terbatas di perairan Prigi. Penelitian ini bertujuan untuk mengungkap beberapa aspek biologi ikan tembang hasil tangkapan pukat cincin di perairan Prigi dan sekitarnya. Penelitian berlangsung selama lima bulan, dari Mei hingga September 2019. Ikan tembang yang dijadikan contoh merupakan hasil tangkapan pukat cincin yang didaratkan di PPN Prigi. Contoh ikan yang diukur panjang dan ditimbang bobotnya berjumlah 705 ekor. Tiga ratus diantaranya kemudian dibedah untuk diamati jenis kelamin dan tingkat kematangan gonadnya secara visual. Analisis data dilakukan menggunakan regresi power yang diuji menggunakan uji-t untuk hubungan panjang bobot, uji khi kuadrat untuk menentukan keseimbangan nisbah kelamin, dan fungsi logistik untuk menentukan ukuran pertama kali ikan matang gonad. Panjang cagak ikan yang dianalisis berkisar antara 91-183 mm dengan ikan terbanyak pada selang kelas 110-119 mm. Pola pertumbuhan ikan tembang adalah allometrik negatif dengan nisbah kelamin yang seimbang. Ukuran pertama kali matang gonad ikan tembang di perairan Prigi dan sekitarnya adalah 128 mm. Sebagian besar ikan tembang yang tertangkap pada alat tangkap pukat cincin adalah ikan tembang yang masih belum dewasa.Goldstripe sardinella (Sardinella gibbosaBleeker, 1849) is a kind of small pelagic fish, economically important and caught a lot in Prigi and adjacent waters. The information regarding this fish was still very limited in Prigi waters. This study aimed to reveal several aspects of the biology of goldstripe sardinella caught by purse seine in Prigi and adjacent waters. The research was held for five months, from May to September 2019. Fish samples were from purse seiners that landed the caught at PPN Prigi. There were 705 fish measured and weighed. Three hundred of them were dissected to be observed the sex and gonadal maturity visually. Data analysis was performed using power regression which was tested using t-test for the relationship of weight length, chi-square test to determine the balance of sex ratio, and logistic function to determine the first length of maturity. The length of the fish was ranged from 91-183 mmFL and mostly was at 110-119 mmFL length class. The growth pattern of the goldstripe sardinella was allometric negative with a balanced sex ratio. The first length of maturity for goldstripe sardinella in Prigi and adjacent waters was 128 mm. Most of the fish which were caught by purse seine were still immature.

scholarly journals Influence of Microalgae Diets on the Biological and Growth Parameters of Oithona nana (Copepoda: Cyclopoida)

Animals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3544
Author(s):  
Jordan I. Huanacuni ◽  
Renzo Pepe-Victoriano ◽  
María C. Lora-Vilchis ◽  
Germán E. Merino ◽  
Fressia G. Torres-Taipe ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Growth Parameters ◽  
Ingestion Rate ◽  
Isochrysis Galbana ◽  
Population Level ◽  
Individual Growth ◽  
Mixed Diet ◽  
Final Population ◽  
Chaetoceros Calcitrans ◽  
Copepoda Cyclopoida

Several species of the planktonic free-living genus Oithona have been successfully used in the larviculture of marine fish and shrimp. However, few studies have been published that allow us to estimate the potential of Oithona nana culture under controlled conditions. This work evaluated the effect of the microalgae Isochrysis galbana and Chaetoceros calcitrans as single (200,000 cells/mL) and mixed diets (100,000 + 100,000 cells/mL) on population and individual growth, ingestion rate, number of spawnings, fertility, development time by stage, and sex ratio of O. nana. We cultured this copepod at 28 ± 0.5 °C, 35 PSU salinity, 125 lux, and 12:12 photoperiod. Results showed that diet had no effect on the final population level (6273–7966 ind/L) or on individual growth, nor on sex ratio, with less males than females. With C. calcitrans, O. nana had a higher filtration rate (57 ng C/ind/day). On the other hand, a mixed diet induced a higher number of spawns (0.4 events/day) and nauplii per spawn (23 ind). Similarly, a single or mixed diet, containing I. galbana, accelerated the development rate by 6.33–7.00 days. We concluded that O. nana can be cultured with both microalgae, indicating its potential use in an intensive system for production. However, more research is required to improve the productivity of O. nana rearing.

scholarly journals Population structure and growth of the hermit crab Pagurus brevidactylus (Anomura: Paguridae) from the northern coast of São Paulo, Brazil

2005 ◽  
Vol 85 (1) ◽  
pp. 127-128 ◽  
Author(s):  
F.L. Mantelatto ◽  
R.A. Christofoletti ◽  
W.C. Valenti
Keyword(s):  
Population Structure ◽  
Sex Ratio ◽  
Hermit Crab ◽  
Sexual Maturity ◽  
Scuba Diving ◽  
Northern Coast ◽  
Short Life ◽  
Continuous Reproduction ◽  
Shield Length ◽  
Number Of Males

The hermit crab Pagurus brevidactylus (Crustacea: Anomura: Paguridea) from the infralittoral area of Anchieta Island, Ubatuba, was characterized by population structure (size, sex ratio, reproduction and recruitment) and growth. Animals were collected monthly during 1999 by SCUBA diving. A total of 1525 individuals was collected (633 males and 892 females), 695 of them were ovigerous females. Overall sex ratio was 0·7:1 in favour of females. The crabs showed a unimodal distribution with males significantly larger than females. Ovigerous females were collected during all months and in high percentages from 1·0 mm of shield length, demonstrating intense and continuous reproduction. The longevity was approximately 24 months for males and 18 for females, which showed larger growth rate and reached sexual maturity earlier (two months) than males. The low number of males in this population may be due to the longer life span. Moreover, the sexual dimorphism favours males during the intra- and interspecific fights by shell, food, reproduction and territory. Females demonstrated a short life cycle and intense reproduction.

Annual cycle of growth and population structure of the estuarine crab Hemigrapsus crenulatus (Brachyura: Varunidae) off central Chile

2021 ◽  
pp. 1-15
Author(s):  
Ramiro A. Riquelme-Bugueño ◽  
Tomás Luppi ◽  
Gonzalo S. Saldías ◽  
Marcelo E. Lagos ◽  
Mauricio A. Urbina ◽  
...  
Keyword(s):  
Population Structure ◽  
Sex Ratio ◽  
Size Distribution ◽  
Annual Cycle ◽  
Linear Models ◽  
Environmental Variability ◽  
Growth Parameters ◽  
Austral Summer ◽  
Size Frequency Distribution ◽  
Central Chile

Abstract Estuaries and saltmarshes play a fundamental role in the life cycle of many crab species. Diverse studies show that temperature and salinity modulate abundance, size frequency distribution (SFD), sex ratio and growth in crustaceans. These population parameters are usually challenging to estimate due to the high environmental variability of estuaries. Monthly samples of the estuarine crab Hemigrapsus crenulatus were taken from October 2003 to October 2004 (except July 2004) in the Tubul estuary, central Chile. We quantified temporal changes in abundance, size distribution, sex ratio and monthly growth through the annual cycle. A total of 1025 individuals were collected. Sizes ranged from 7.72–33.51 mm carapace length (CL) with a growth rate ranging between 2.13–30.5% mm CL mo−1. Size and growth rates were greater in spring-summer, suggesting a faster growth of younger crabs correlated with increasing sea temperatures in the austral summer. Overall, sex ratio was 1.75:1 in favour of males. Modal analysis identified at least seven cohorts cohabiting throughout the annual cycle. Growth parameters for males and females were the following, respectively: L∞ = 33.6 and 29.6, k = 0.69 and 0.91, t0 = –0.39 and −0.28. Changes in size distribution suggested a recruitment period during autumn and winter seasons when there are lower salinities and temperature fluctuations stresses. Generalized linear models indicated that sea temperature, salinity and chlorophyll were the environmental variables that better predicted the annual patterns in the population structure.

scholarly journals Estructura de la población del cangrejo rojo de manglar, Goniopsis cruentata (Decapoda: Grapsidae) bajo diferentes impactos de pesca: Implicaciones para la gestión de los recursos.

2015 ◽  
Vol 63 (2) ◽  
pp. 443 ◽  
Author(s):  
Gustavo L. Hirose ◽  
Laize S. Souza ◽  
Sonja L. R. Silva ◽  
Douglas F. R. Alves ◽  
Maria Lucia Negreiros-Fransozo
Keyword(s):  
Body Size ◽  
Sex Ratio ◽  
Sexual Maturity ◽  
Abiotic Factors ◽  
Mangrove Ecosystem ◽  
The Body ◽  
Sediment Surface ◽  
Brazilian Coast ◽  
Catch Per Unit Effort ◽  
Fishery Resource

<p>The red mangrove crab, <em>Goniopsis cruentata,</em> influences the recruitment and composition of plant species in the mangrove ecosystem and it is an important fishery resource. Nevertheless, no current management and conservation plans are available for this species for the Brazilian coast. This investigation evaluated the population structure and reproductive biology in populations of <em>G. cruentata</em> under contrasting fishery pressures. The sampling program was carried out in two mangroves, Vaza-Barris and Sergipe River, from January through December 2011. Crabs from both mangroves were randomly collected by a professional fisherman during daytime low tide periods, using a fishing rod baited with pieces of a locally abundant gastropod, <em>Pugilina morio</em>, during 20min/area (catch per unit effort). Monthly measurements of air, sediment surface layer and water temperatures were obtained with a digital thermometer and salinity with an optical refractometer. Both crab populations were compared concerning their abundance, body size, sex ratio, size at onset of sexual maturity and fecundity (FI). Abiotic factors (air, water and mud temperature; and salinity) showed no significant differences between sampling localities. A total of 4 370 crabs were sampled, 2 829 from the Sergipe River and 1 541 from the Vaza-Barris River. The abundance and body size of crabs were compared between mangroves, and statistically significant differences were found. The sex ratio for both populations differed from the expected 1:1 ratio, and a significant deviation in favor of juvenile males was obtained, while adults showed a bias toward females. The estimated size at onset of sexual maturity for both sexes was similar in both populations. However, the populations differed significantly in the number and volume of eggs: a higher FI was obtained in females from the Sergipe River, while a higher egg volume was observed in females from the Vaza-Barris River mangrove. These results indicated a tendency to decrease the body size, the abundance of crabs and the reproductive potential of the species, with higher fishing intensities, reinforcing the need to develop a management plan as well as to establish conservation units for <em>G. cruentata</em> in the Northeastern Brazilian coast. Habitat loss in conjunction with long-term overfishing can have irreversible consequences, which can impact not only the populations of commercially exploited crabs, but the dynamics of virtually the entire mangrove ecosystem.</p>

Contribution to the study of the reproductive cycle of the wide-eyed flounder Bothus podas podas in the Gulf of Gabès (Tunisia)

2010 ◽  
Vol 90 (3) ◽  
pp. 519-526 ◽  
Author(s):  
S. Abid ◽  
A. Ouannes-Ghorbel ◽  
O. Jarboui ◽  
A. Bouain
Keyword(s):  
Sex Ratio ◽  
Sexual Maturity ◽  
Logistic Function ◽  
Sexual Cycle ◽  
Small Fish ◽  
Gulf Of Gabes ◽  
Spawning Period ◽  
Gulf Of Gabès ◽  
Gonad Somatic Index ◽  
Somatic Index

The wide-eyed flounder Bothus podas podas is a small fish that belongs to the Bothidae family. This species is a demersal fish inhabiting sandy and muddy bottoms where it lives buried in the sand. In the Gulf of Gabès (Tunisia), B. podas podas is an uncommon fish caught in small quantities by trawlers, between depths of 20 and 50 m. There are very few complete studies of the biology of this fish in the Mediterranean Sea. Even in Tunisia, the biology of B. podas podas is unknown. In addition, it has been noticed that during the last few years, despite having weak commercial value, this fish has attracted the fishermen's attention of the region after the observed reduction in the flat fish stocks, particularly the Egyptian sole Solea aegyptiaca. The aim of this work was to study the reproduction of B. podas podas and determine the sex-ratio, the sexual cycle, the spawning period and the first sexual maturity. The data for this work was collected during the period of May 2004 until September 2005. In general, this study shows that the proportion of sexes is in favour of females and permits us to analyse the sex-ratio variations according to the size and age of the fish. It also seems that males grow faster than females. The monthly following of the gonad somatic index (GSI), the liver somatic index (LSI) and the condition factor (K) enabled us to determine that the period of maturation occurs from May to August, to define the spawning period from August to November and to deduce that B. podas podas uses the lipid reserves accumulated in the liver to develop its gonads. Concerning the first sexual maturity it was noted that the main size related to 25%, 50% and 75% of matured individuals were respectively for males: 19.68 cm, 21 cm and 22.34 cm and for females: 18.87 cm, 20.4 cm and 21.93 cm. The coefficients of the logistic function were for males: a = 0.827, b = 17.38 and for females: a = 0.718, b = 14.65.

Fecundity and Gonado-somatic Index of Trichiurus lepturus (Linnaeus, 1758) Along the Zamboanga del Norte Coast

2018 ◽  
Vol 6 (7) ◽  
pp. 120
Author(s):  
Ma. Dulce C. Guillena
Keyword(s):  
Sex Ratio ◽  
Stock Assessment ◽  
Chi Square ◽  
Moon Phases ◽  
Ovary Weight ◽  
Moment Coefficient ◽  
Trichiurus Lepturus ◽  
Significant Difference ◽  
The Relationship ◽  
Somatic Index

Gonado-somatic index and fecundity are tools for measuring the sexual maturity and ability of animals to reproduce.  This study investigates the reproduction of Trichiurus lepturus. Specifically, this aimed to determine the sex ratio, the GSI, the relationship between fecundity and total length, fecundity and total weight, fecundity and ovary weight. The Descriptive Method of research was used.  Percentage and chi-square was utilized in determining the percentage of occurrence and sex ratio respectively.   Pearson r Product Moment Coefficient of Correlation was used to determine the relationships of the parameters. The study revealed that females outnumbered males and the sex ratio for different month showed significant difference.  Spawning season was observed to occur in November and December as revealed in its GSI values and it synchronized with the full and new moon phases.  Fecundity is positively correlated with body weight, body size, and ovary weight where ovary weight is observed to be the best index for fecundity.  The results of this study could be used further for formal stock assessment of cutlassfish fishery.

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