e have now reached the milestone on ScotCat
of the 160th factsheet since 1997 and this month (October 2009)
we have been joined by Catfish expert and author, Chris Ralph
and his take on one of the Rift Valley Mochikids, Synodontis
Synodontis polli belongs to the
family Mochokidae known as the Squeaker Catfishes or Upside-down
Catfishes from Africa and is naturally found in Lake Tanganyika.
It is also documented as being found in Burundi, the Congo Democratic
Republic, Tanzania and Zambia. Reference is made to the fact that
this catfish occurs in the Western Rift Valley Lakes.
The catfish featured appears as Synodontis eurystomus
in the book ‘Revision Des Synodontis Africains (Famille
Mochocidae)’ by Max Poll, who worked extensively in the
field with fish from Lake Tanganyika and the River Congo.
I have seen a few of these truly stunning
catfish available for sale over the years and I would suggest
that you would expect to pay around £20.00- £30.00
per fish (2007 U.K. prices) depending upon size. This catfish
features in the recent ‘Taxonomic Revision of Lake Tanganyikan
Synodontis’ by Jeremy Wright and Lawrence Page. It would
appear that Synodontis polli has a wide distribution
within Lake Tanganyika and some slight colour variations amongst
the populations present.
Synodontis polli prefer to be kept in water which has
a pH in the range of 7.5-9.2. This catfish is ideally suited to
temperatures in the range of 23-29ºC or 73-84°F. and
they prefer hard water conditions which is very clean and stable
in terms of pH.
I would suggest a minimum size of 60” x 18” X 18”
for a small shoal of these magnificent catfish. I would suggest
good quality aquarium sand such as BD Aquarium Sand, or very smooth
rounded gravel as the preferred substrate when keeping these catfish.
The aquarium should provide some shelter in the form of rocks
or bogwood along with a small covering of aquatic plants, although
this is not essential. As with all other species of fish, water
quality and general husbandry is very important, and I would recommend
that a minimum of 25% water is changed on a weekly basis.
The body shape of Synodontis polli is
described as being compressed. The head is also described as being
compressed and the body is described as being naked. The mouth is
described as being inferior with wide lips (from the original description
of Synodontis eurystomus which means ‘wide mouth’).
It is documented that this catfish has 40-70 mandibular teeth which
are described as being short, uncuspid and arranged in 6-8 short
transverse rows. It has three pairs of barbels which are described
as being short, with the maxillary barbels having a small membrane
at the base. The mandibular barbels have slender ramifications.
Synodontis polli is described as having a cusp on the dorsal
edge of the humeral process. The dorsal fin is described as having
7 soft rays. The pectoral fin is described as having 8-9 soft rays.
The caudal fin is described as being forked with rounded lobes.
The base colour of the body and head is
described as being creamy white to light brown with black spots
and blotches scattered irregularly over the body. The ventral
region is described as being lighter in colour. The dorsal, caudal,
pectoral, anal and ventral fins are described as having white
outer edges to them, with similar colouration to the body eventually
turning black in colour towards the outer borders of the fins.
It is documented that adult males are chocolate brown in colour
with numerous black spots, with dull white edging on the posterior
edges of the fins. Juvenile specimens are described as having
lighter colouration and somewhat brighter white coloured fin edging.
Synodontis polli is an ideal addition
to an aquarium containing fish such as other species of African
Rift Lake catfish and cichlids, large tetras and large barbs, just
as long as the other occupants are not too aggressive. It is documented
that newly added males will fight with one another until territories
have been established.
There have been a number of reports of
successful aquarium spawnings of Synodontis polli. Bob
Barnes of the Catfish Study group has been breeding them for a
number of years and there have also been breeding attempts in
the Czech Republic using hormone injection, and it is generally
thought that there are now a few hybrids available to the hobbyist
resulting from these breeding attempts.
Synodontis polli readily accepts
a mixed and varied diet which includes sinking foods such as catfish
pellets, tablets and frozen bloodworm. These catfish benefit from
the addition of some meatier foods in their diet such as prawns
and mussels. Their natural diet would include insects and crustaceans.
|The males tend to be larger
and more robust than the females and when viewed from underneath
exhibit external genital papilla.
is defined as the medial fin on top of back.
Caudal fin is defined as the tail fin.
Anal fin is defined as the medial fin immediately
posterior to the anus.
Pectoral fins are defined as the paired
Ventral fins are defined as being the paired
fins between the pectoral and anal fins (also referred to
as pelvic fins).
Maxillary is defined as being in relation
to the maxilla, the bone of the upper jaw.
Mandibular is defined as being in relation
to the mandible or lower jaw.
Anterior is defined as being in front.
Posterior is defined as being situated
Ramifications are defined as side branches.
Compressed is defined as flattened from
side to side.
Ventral is defined as being bottom, below
Papilla is defined as being a small fleshy
Ancient name for an undetermined fish from
the Nile (Cuvier 1816).
Polli: in honour of Dr. Max Poll
an eminent Belgian ichthyologist.
Jeremy J Wright
and Lawrence M Page,
Taxonomic Revision of Lake Tanganyikan Synodontis (Siluriformes:
Allan James @