Life History and Spawning Behavior

as of July 2018

The table below provides information on specific life history and spawning behavior parameters for 28 species of marine fishes in the Gulf of Mexico. These parameters were selected, because they are directly correlated with resilience or vulnerability to fishing pressure and environmental variation in marine fishes. The parameters related to spawning behavior (aggregation type, spawning season duration, density change) are those known to be important for assessing the vulnerability of spawning aggregations to fishing pressure. These parameters represent how far individuals travel to form fish spawning aggregations (FSAs), how long they aggregate to spawn, and how densely they aggregate. For example, fishes that travel vast distances to aggregate in large numbers for a short and very predictable time period at a specific location will be highly vulnerable to exploitation. Conversely, fishes that form many aggregations that each hold fewer fish, are distributed widely, and persist for several months will be much less vulnerable to exploitation.

The remaining parameters were chosen to represent the life history of the species, and indicate their natural productivity or resilience to exploitation. One can see that a large species with a long lifespan and generation time that grows slowly and sustains a high level of natural mortality will not be equipped to handle a high rate of exploitation. Similarly, a small species with a short lifespan and generation time that grows quickly and sustains a low level of natural mortality would likely be able to withstand a relatively high level of exploitation. These parameters may be used in conjunction with parameters that represent fisheries and management to determine the vulnerability of these fishes to exploitation under current management regimes.

Additional details and information on life history parameters, types of spawning aggregations, and other aspects can be found in the “Methods” section of the website.

(Click here to download the full dataset in Excel file with notes, metadata, and references included)

Suggested Citation for Data set (Excel file)
Biggs, C., B. Erisman, W. Heyman, S.Kobara, N. Farmer, S. Lowerre-Barbieri, M. Karnauskas, and J. Brenner. (2018). Cooperative monitoring program for spawning aggregations in the Gulf of Mexico: Life History and Spawning Behavior. Version 2018.07. Available from GCOOS Web site:

Name FMP Category Family Scientific Name Aggregation Type Spawning Season Months Spawning Season Duration (1-4) Density Change (1-4) Max Age (yr) Max Weight (kg) Max Length (cm) K vB Growth Coeff. Linf Asym. Length (cm) Age at length 0 (yr) Age at Maturity (months) Length at Maturity (cm) Natural Mortality
** No data/records leave blank.
Age (Max, 0, Maturity)
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Length (Max, Maturity)
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Max Weight
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K Growth Coefficient & Mortality
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Life History Parameters

FMP Fisheries Management Plan management unit
Common Name American Fisheries Society Common Name
Family Family
Scientific Name Genus and Species names
Aggregation Type (1-4) The type of spawning aggregation: Does Not Aggregate; Unknown; Simple Migratory Spawner; Resident Spawning Aggregation; Transient Spawning Aggregation.
Spawning Season Months Months of spawning, with peak months in bold. (J, F, M, A, Ma, Ju, Jl, Au, S, O, N, D)
Spawning Season Duration (1-4) Scales the duration of the spawning season ranging from 1-3 months = 4, 4-6 months = 3, 7-9 months = 2 and 9-12 months = 1, with shorter spawning seasons conferring higher vulnerability to aggregation fishing
Density Change (1-6) Based on order of magnitude comparisons between peak spawning aggregation densities and population densities during non-spawning period. Scale distinguishes between species that are solitary, grouping or schooling for non-reproductive functions. Larger density changes confer higher vulnerability to aggregation fishing. No change in densities between spawning and non-spawning periods = 1; density doubles from solitary to few to ca. 10 fish (clustering of polygynous groups) = 2; density increases from small groups to 100-200 fish = 3; density increases from small groups to 500-1000 fish = 4; density increases from small groups to 1,000-10,000 fish =5; density increases from small groups to >10,000 fish = 6
Max Age (years) Maximum age in years (longevity)
Max Weight (kg) Maximum weight in kilograms.
Max Length (cm) Maximum reported length for the species in centimeters
K (vB Growth Coefficient) von Bertalanffy growth coefficient
Linf(Asymptotic Length, cm) Asymptotic length for von Bertalanffy growth equation, expressed in centimeters
t0(time at length zero, years) Time at length zero for von Bertalanffy growth equation, expressed in years
Age at Maturity (months) Age at 50% maturity in months
Length at Maturity (cm) Length at 50% maturity in centimeters
M (Natural Mortality) Death rate per year not associated with fishing