Mary Opiyo
I am interested in sustainable aquaculture production and use of novel products in fish health management. My other interest is reducing the use of fish meal in fish diets to save the wild fishery from over-exploitation. Fish breeding and quality seed production is my passion. I have 14 years of experience in the fisheries and aquaculture sector both in the public sector and have collaborated with the private sector in different aquaculture projects. I have worked closely with all the links on the aquaculture value chain from production to market. Training across the value chain, group formation to create networks that enable quality and sustainable aquaculture. I have managed more than 18 donor-funded projects as the Project manager, Coordinator and researcher in various aspects of aquaculture supported by I have managed more than 17 donor funded projects as the Project manager, Coordinator and researcher in various aspects of aquaculture with funding and collaboration from LIDC, ICIPE, UK-RI, VLIR-UOS, BBSRC, STFC, KCSAP, ASARECA, VicRes-IUCEA and KAPAP with funding from DfID, European Union (EU), SIDA and World Bank.
Address: Kenya
Address: Kenya
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Papers by Mary Opiyo
species in the world. The current study evaluated the spawning interactions between
naturalized and wild rainbow trout from two high-altitude second-order streams,
in Kenya. Data on total length, weight, condition factor, fecundity, fertilization, egg
diameter and fry survival were collected on spawning rainbow trout between March
and December 2021. Length–weight relationship showed parabolic equations as
W = 0.0144L2.900, W = 0.0069L3.0285 and W = 0.00027L3.175 for wild fish stock,
hatchery-reared and wild × hatchery-reared rainbow trout, respectively. Total fecundity
differed significantly among the hatchery-reared, wild fish and the cross of
the two (p < 0.05). The fertilization rate showed significant differences (p < 0.05),
with no discernable difference observed between the hatchery-reared and crossed
(wild × hatchery-reared). There was a positive correlation among the total fecundity
to female egg weight, female body weight, fertilization rate and eyed egg survival
in all the populations. Relative fecundity was significantly different among the three
groups of fish (p < 0.05), but the differences between the hatchery and the crossed
(wild × hatchery-reared) fish showed no significant differences. We recommend the
use of crossed (wild × hatchery-reared) populations for fry production for use in aquaculture
as they presented the highest fecundity and gave the best outcome of fry with
high survival.
KEYWORDS
aquaculture, fecundity, interactions, naturalized rainbow trout, tropical streams
species in the world. The current study evaluated the spawning interactions between
naturalized and wild rainbow trout from two high-altitude second-order streams,
in Kenya. Data on total length, weight, condition factor, fecundity, fertilization, egg
diameter and fry survival were collected on spawning rainbow trout between March
and December 2021. Length–weight relationship showed parabolic equations as
W = 0.0144L2.900, W = 0.0069L3.0285 and W = 0.00027L3.175 for wild fish stock,
hatchery-reared and wild × hatchery-reared rainbow trout, respectively. Total fecundity
differed significantly among the hatchery-reared, wild fish and the cross of
the two (p < 0.05). The fertilization rate showed significant differences (p < 0.05),
with no discernable difference observed between the hatchery-reared and crossed
(wild × hatchery-reared). There was a positive correlation among the total fecundity
to female egg weight, female body weight, fertilization rate and eyed egg survival
in all the populations. Relative fecundity was significantly different among the three
groups of fish (p < 0.05), but the differences between the hatchery and the crossed
(wild × hatchery-reared) fish showed no significant differences. We recommend the
use of crossed (wild × hatchery-reared) populations for fry production for use in aquaculture
as they presented the highest fecundity and gave the best outcome of fry with
high survival.
KEYWORDS
aquaculture, fecundity, interactions, naturalized rainbow trout, tropical streams