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 polli.
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
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
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.
Tanganyika. Type locality: Luhanga,
145mm S.L. (standard length
– this is the measurement of the fish from the
tip of the snout to the base of the caudal peduncle).
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
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.
Care & Compatibility
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
The males tend
to be larger and more robust than the females and
when viewed from underneath exhibit external genital
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
Anal fin is
defined as the medial fin immediately posterior to
the anus. Anterior is defined as being in front.
Caudal fin is defined as the tail fin.
Compressed is defined as flattened from side
Dorsal fin is defined as the medial fin on
top of back. Mandibular is defined as being in
relation to the mandible or lower jaw. Maxillary is defined as being in
relation to the maxilla, the bone of the upper jaw.
Papilla is defined as being a small
fleshy projection. Pectoral fins are defined as the
paired lateral fins. Posterior is defined as being situated
behind. Ramifications are defined as side
branches. Ventral is defined as being bottom,
below or underneath. Ventral fins are defined as being
the paired fins between the pectoral and anal fins
(also referred to as pelvic fins).
From the Greek syn, meaning together, and odontos,
meaning tooth; in reference to the closely-spaced
lower jaw teeth. Polli: in honour of Dr.
Max Poll an eminent Belgian ichthyologist.
J Wright and Lawrence M Page,
Taxonomic Revision of Lake Tanganyikan Synodontis