Page 22 - Vol.36-No.8 issue

FISHERIES

BROODSTOCK DIETS – AN OVERVIEW

The use of fresh and frozen seafood as commonly used. In many hatcheries,
a partial or complete diet for broodstock these moist diets are produced in-house.
is still the standard with many marine
species, including established species
such as gilthead sea bream and Euro-
pean sea bass, shrimps. While there are
commercial broodstock diets that can
be used solely, marine organisms such
as sardines, mackerels, squid, mussels
and polychaetes are considered to be
essential for marine fish and shrimp
Dr Sagiv Kolkovski broodstock.

Nutrakol Australia In shrimp aquaculture, significant ef-
info@nutrakol.com forts are made to grow polychaetes,
which together with squid and Artemia While the nutritional requirements of
Broodstock are considered to be the are considered as essential for brood- fish and shrimp broodstock may not be
core of any fish and shrimp hatchery and stock. Large hatcheries and breeding fully described(especially for ‘new’ cul-
their physiological and nutritional con- centers usually have their own poly- tured species such as groupers Epineph-
ditions are the keys to their success. chaete tanks. Although this practice has alus sp., Seriola sp., Cobia, and many oth-
It is well established that high fecun- a potential risk for introducing pathogen ers), they are partially or fully fulfilled
dity results in high quality larvae and vectors which may affect broodstock with the supplementation of fresh feeds
therefore, optimal growth and survival quality, the global shrimp industry is and nutritional boosters.
are dependent on the broodstock nutri- still reliant on live polychaetes and other Current commercial broodstock diets
tion and their health. fresh and frozen feeds. and supplements focus on the nutrition-
The effect of nutrients on gonadal de- In general, there are no ‘standard’ al requirements of the fish and shrimps.
velopment, maturation and fecundity of feeding protocols for marine fish brood- However, additives or supplements that
different aquatic species has been the stock and the nutrition and feeding pro- support the hormonal cycle, and thus
subject of research efforts for decades. tocols can vary significantly between will lead to better gonadal development
This research includes protein levels hatcheries and species. A mix of seafood and higher fecundity, are scarce. This is
and amino acids, levels and fractions of such as sardines, mackerels and squid, especially true for out-of-season brood-
phospholipids, essential fatty acids (es- in addition to commercial boosters and stock groups of well-established and
pecially DHA, EPA, ARA) and vitamins broodstock diets containing vitamins, new species in aquaculture.
such as ascorbic acid (C) and α-tocoph- minerals, fatty acids and other nutrients Moreover, other factors affecting the
erol (E), in addition to many others. Spe- are usually the norm. broodstock fecundity and maturation
cific nutrients such as carotenoids, yeast such as stress and immune and diges-
extracts and microalgae (Spirolina, Chlo- tive systems are not usually directly ad-
rella, Dunaliella salina) have been found dressed.
to have a significant effect on fecundity
and are currently included as a standard While phytomedicine and herbal ther-
in broodstock diets. apy for women with reproductive hor-
monal problems has been recognized
Although there is a significant quanti- for centuries, there is very little adapta-
ty of scientific literature on broodstock tion of it in aquaculture.
nutrition of marine fish and crustaceans,
there are still many factors which are Medicinal plants are known to have
unknown. Due to the large number of hormonal boosting effects. Some herbs
species grown in aquaculture (which, in are utilised in herbal medicine as natu-
many cases are varied in habitat, behav- ral boosters for the hormonal cycle and
ior, feeding habits, activity etc.) there is the development of gametes in both men
no one (or even several) optimal formu- and women. There are specific herbal
lae that can suit all species. For example, extracts mixtures used as hormonal re-
nutritional requirements for flat fish such placement therapy (‘HRT’) for meno-
as Solea solea are significantly differ- pausal women.
ent than pelagic species such as Seriola The effect of herbal extracts on the
lalandi. As Cobia Rachycentron canadum development and performance of fish
is a tropical species, it has significant- and shrimp broodstock have not been
ly different requirements than Halibut intensively investigated. However, scien-
Hippoglossus sp., which is a cold water tific evidence suggests that aside from
species. While in recent years, more In addition, moist diets based on a mix known properties of plant extracts such
species-specific maturation diets have of fishmeal and other marine organism as antibacterial, antiviral and antifungal,
become available, the nutrition of brood- meals such as krill and squid, oils and these compounds can significantly im-
stock is still far from optimal. nutritional additives, as well as, fresh in- prove broodstock condition and there-
gredients (squid, fish) and binders are
fore, the quality of their eggs and larvae.
20 Vol. 36 No. 8