Jason Martinez
ID: 4246155
PCB 3043L
February 15, 2016
Vertical Life History Table for Gambusia holbrooki Collected from Hennington Pond
U05
Catherine Bravo
Table of Contents
Abstract………………………………………………………………………………………..Pg. 3
Introduction……………………………………………………………………………………Pg. 3
Methods…………………..…………………………………………..……………………….Pg. 4
Results………………………………………………………………………………………...Pg. 8
Discussion…………………………………………………….………...……………………..Pg. 9
References…………………………………………...……………………….…………...….Pg. 9
Abstract:
Introduction: The Gambusia holbrooki, also known as the eastern mosquitofish, live in areas of freshwater. They are commonly confused with a similar species known as the Gambusia affinis, or western mosquitofish, …show more content…
One of the many factors relates to the length of male Gambusia holbrooki. The way these fish produce offspring is through an insemination process that occurs where the male fish “sneak[s] up” on the female species and inserts their gonopodia (an anal fin that males use to insert into the female’s sexual organ to deposit sperm and reproduce) into the female for fertilization (O’Dea). It was discovered that females tend to prefer longer gonopodium for fertilization. However, males with longer gonopodium have an incline to lose maneuverability, so, greater length serves them as a drawback in their reproductive approach (Magellan). In other words, smaller lengths is more beneficial because they have more rapid mobility and are able to reach the female with less effort (Head).
The length of the Gambusia holbrooki also plays a role in the survival rates, along with the body color of the fish. Approximately ninety-nine percent of this species develops a silver pigmentation while one percent produce a melanic (black spotted) pigmentation. The melanic species tends to have larger bodies than the silver species, which is advantageous during their survival in conspecific competition. The larger body size of melanic Gambusia holbrooki also benefits them in their survival against predators (Horth).
The objective of this experiment was to create vertical life history tables for the Gambusia holbrooki species and analyze …show more content…
1. Summary of Length and Age data for Gambusia holbrooki taken from Hennington Pond.
Example 2: Vertical Life Table for a Gambusia holbrooki population
Age class (days) x Sample/age class s(x) Number/age class n(x) Survival rate l(x) Fecundity b(x) Offspring/ind l(x)*b(x) Age-weighted fecundity l(x)*b(x)*x 0 130 759 1.00 0.00 0.00 0.00
30 190 629 0.829 0.00 0.00 0.00
60 240 439 0.578 0.00 0.00 0.00
90 120 199 0.262 24.00 6.29 566.32
120 60 79 0.104 27.00 2.808 336.96
150 15 19 0.025 29.00 0.73 108.89
180 3 4 0.005 32.00 0.17 30.36
210 1 1 0.001 0.00 0.00 0.00
240 0 0 0.000 0.00 0.00 0.00 Sum 759 9.998 1042.53 R0 9.998 offspring G 104.27 days r 0.0221 ind/day Optimal age for sexual maturity 90 days
Fig. 2. Example of a Vertical Life Table taken from Example 2 for reference.
ID: 4246155
PCB 3043L
February 15, 2016
Vertical Life History Table for Gambusia holbrooki Collected from Hennington Pond
U05
Catherine Bravo
Table of Contents
Abstract………………………………………………………………………………………..Pg. 3
Introduction……………………………………………………………………………………Pg. 3
Methods…………………..…………………………………………..……………………….Pg. 4
Results………………………………………………………………………………………...Pg. 8
Discussion…………………………………………………….………...……………………..Pg. 9
References…………………………………………...……………………….…………...….Pg. 9
Abstract:
Introduction: The Gambusia holbrooki, also known as the eastern mosquitofish, live in areas of freshwater. They are commonly confused with a similar species known as the Gambusia affinis, or western mosquitofish, …show more content…
One of the many factors relates to the length of male Gambusia holbrooki. The way these fish produce offspring is through an insemination process that occurs where the male fish “sneak[s] up” on the female species and inserts their gonopodia (an anal fin that males use to insert into the female’s sexual organ to deposit sperm and reproduce) into the female for fertilization (O’Dea). It was discovered that females tend to prefer longer gonopodium for fertilization. However, males with longer gonopodium have an incline to lose maneuverability, so, greater length serves them as a drawback in their reproductive approach (Magellan). In other words, smaller lengths is more beneficial because they have more rapid mobility and are able to reach the female with less effort (Head).
The length of the Gambusia holbrooki also plays a role in the survival rates, along with the body color of the fish. Approximately ninety-nine percent of this species develops a silver pigmentation while one percent produce a melanic (black spotted) pigmentation. The melanic species tends to have larger bodies than the silver species, which is advantageous during their survival in conspecific competition. The larger body size of melanic Gambusia holbrooki also benefits them in their survival against predators (Horth).
The objective of this experiment was to create vertical life history tables for the Gambusia holbrooki species and analyze …show more content…
1. Summary of Length and Age data for Gambusia holbrooki taken from Hennington Pond.
Example 2: Vertical Life Table for a Gambusia holbrooki population
Age class (days) x Sample/age class s(x) Number/age class n(x) Survival rate l(x) Fecundity b(x) Offspring/ind l(x)*b(x) Age-weighted fecundity l(x)*b(x)*x 0 130 759 1.00 0.00 0.00 0.00
30 190 629 0.829 0.00 0.00 0.00
60 240 439 0.578 0.00 0.00 0.00
90 120 199 0.262 24.00 6.29 566.32
120 60 79 0.104 27.00 2.808 336.96
150 15 19 0.025 29.00 0.73 108.89
180 3 4 0.005 32.00 0.17 30.36
210 1 1 0.001 0.00 0.00 0.00
240 0 0 0.000 0.00 0.00 0.00 Sum 759 9.998 1042.53 R0 9.998 offspring G 104.27 days r 0.0221 ind/day Optimal age for sexual maturity 90 days
Fig. 2. Example of a Vertical Life Table taken from Example 2 for reference.