The African Sharptooth Catfish (Cla

The African Sharptooth Catfish (Clarias gariepinus)
grow up to 1.17 m long and the adult fish weighs 10 - 25 kg.
The male adult is slightly larger than the adult female
(Napitapat, 2000). This catfish has yellow colored flesh and
is a popular and delicious fish, especially in the Northern
and Northeastern Regions of Thailand. Researchers have
identified two types of algae as appropriate feed for the
African Sharptooth Catfish: the Spirulina platensis and the
Cladophora.
Cladophora is a member of the Chlorophyta group. It
is a branching alga with attaching filaments that grow out of
the back of the cell. Chloroplast is present in the
Cladophora alga and pyrenoids are present throughout the
plant’s cells. Many nuclei are present in the cytoplasm and
are surrounded by chloroplast (Wongrat, 2001). Spirulina
platensis is a blue-green spiral coiled alga, with the spiral
varying among different species (Promya et al., 2008). The
optimum N: P ratio of kitchen wastewater (Kw) and oilextracted
fermented soybean water (Sw) for cultivation of S.
platensis was evaluated. The highest levels of biomass
production of S. platensis were achieved using 5%Sw (0.90
g/L) and Zm (0.80 g L-1) with an N:P ratio of 6:1 and 6.1:1,
respectively. The highest levels of β-carotene and Cphycocyanin
in S. platensis, were achieved in cultures with
10%Sw (0.37 mg/g and 21.27 mg g-1, respectively (Promya
et al., 2008).
The Spirulina alga is rich in protein and vitamins, and
can be used to improve the immunity capacity of the
animals which consume it. Consumption of Spirulina alga
also increases the ability to absorb nutrients. When
Spirulina alga is used as feed for young prawns and
fingerlings, the fish exhibit good coloring, as well as
maintain a low death rate and a high growth rate
(Sermwattanakul & Bamrungtham, 2000). Previous studies
using the raw Spirulina alga as the primary feed given to the
Nile tilapia feed have found an increase in reproductive,
birth and survival rates, compared with conventional fish
feed. These studies have also found an increase in the
amounts of linoleic acid, gamma-linolenic acid (GLA),
protein and an improved color in the meat of the fish
compared with fish fed on standard instant feeds (Lu &
Takeuchi, 2003). The 3% Spirulina supplemented in pellet
feed and hormone application improved growth and
maturation performance of brood stock Pangasius catfish
(Meng-Umphan, 2009). Previous studies demonstrated their
economic benefits when S. platensis and Cladophora algae