2009
DOI: 10.1590/s1679-62252009000200013
| View full text |Cite
|
Sign up to set email alerts
|

Abstract: Correct estimates of size at first maturity (L 50 ) are useful for fish stock management and different methods have been proposed. In this study we propose the use of a modified logistic to estimate L 50 , including a variable asymptote (A). We also test the use of the Gonadossomatic Index (GSI) as a flag to establish the reproductive status of each female fish. The method is demonstrated using GSI data for four Neotropical fish species: Characiformes: Astyanax fasciatus (n = 473) and Oligosarcus robustus (n … Show more

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...
1
1
1
1

Citation Types

1
52
0
6

Year Published

2016
2016
2024
2024

Publication Types

Select...
8
1

Relationship

1
8

Authors

Journals

citations
Cited by 69 publications
(59 citation statements)
references
References 8 publications
1
52
0
6
Order By: Relevance
“…When L 50 was estimated by using relative frequency of reproductive animals identified through testes or ovarian morphology, the values was 12.5 cm for males (R² = 0.89; p = 0.02) and 13.0 cm for females (R² = 0.97; p = 0.004). By using the G SI method proposed by Fontoura et al (2009), L 50 was estimated as 13.1 cm for males (R² = 0.95; p = 0.003) and 13.7 cm for females (R² = 0.95; p = 0.002). For males, values of L 50 and the stanza changing length (L sc ) were not different taking into account the 95% confidence interval (Table 2), although this was not the case for females, with estimates of L sc 0.5 to 1.0 cm below the estimates of L 50 . )…”
Section: Resultsmentioning
confidence: 99%
See 1 more Smart Citation
“…When L 50 was estimated by using relative frequency of reproductive animals identified through testes or ovarian morphology, the values was 12.5 cm for males (R² = 0.89; p = 0.02) and 13.0 cm for females (R² = 0.97; p = 0.004). By using the G SI method proposed by Fontoura et al (2009), L 50 was estimated as 13.1 cm for males (R² = 0.95; p = 0.003) and 13.7 cm for females (R² = 0.95; p = 0.002). For males, values of L 50 and the stanza changing length (L sc ) were not different taking into account the 95% confidence interval (Table 2), although this was not the case for females, with estimates of L sc 0.5 to 1.0 cm below the estimates of L 50 . )…”
Section: Resultsmentioning
confidence: 99%
“…The other method, the G SI values were transformed into a percentage of the maximum value recorded for the species. As proposed by Fontoura et al (2009) ; where P = the proportion of reproductive/ adult individuals for each size class; A = the asymptote of the curve; r = rate of change between the non-reproductive and the reproductive phase; L t = total length (cm), and L 50 = size at fist sexual maturity, the estimated size (cm) at which 50% of the individuals have reached maturity. In the approach based on the scale of maturity, A = 1.0.…”
Section: Data Analysesmentioning
confidence: 99%
“…Female histological classification of size at maturity was performed using standardized ovarian development classifications (Wallace and Selman 1981), with reproductive maturity assigned to individuals with vitellogenic oocytes, post ovulatory oocytes, or hydrated eggs, because these are signs of spawning activity. Size at maturity was assessed using GSI by classifying maturity using 5, 10, 15, and 20% of the maximum GSI as cutoffs for maturity (Fontoura et al 2009). GSI and histological assessment of size at maturity (L 50 ) were determined as the size at which 50% of individuals were mature for a given fork length (FL: length of the fish from the tip of the snout to the fork or middle of the tail) or age (Lowerre-Barbieri et al 2009).…”
Section: Size At Maturity and Spawning Season Assessmentsmentioning
confidence: 99%
“…In the present study, we aimed to estimate the length at first maturity (L 50 ) according to the Gonadossomatic Index (GSI) using a mathematical approach (Marques et al, 2007;Fontoura et al, 2009) and identify if a polyphasic growth pattern is present for C. paleatus, verifying a possible relationship between the stanza changing length and aspects of the fish biology, as the attainment of sexual maturity.…”
Section: Palavras-chavementioning
confidence: 99%