Synodontis irsacae • Mochokidae • Cat-eLog • PlanetCatfish

Close-up of head
Close-up of mouth showing teeth
Close-up of humeral process
S. tanganaicae above, S. irsacae below
Lateral view

Cat-eLog Data Sheet
Scientific Name	**Synodontis irsacae** Matthes, 1959
Common Name(s)	None
Pronunciation	sin oh don tiss - er say see
Etymology	Synodontis: From the Greek syn, meaning together, and odontos, meaning tooth; in reference to the closely-spaced lower jaw teeth.
Species Information
Size	157mm (6.2") SL. Find near, nearer or same sized spp.
Identification	All species in the genus Synodontis have a hardened head cap that has attached a process (humeral process) which is situated behind the gill opening and pointed towards the posterior. The dorsal fin and pectoral fins have a hardened first ray which is serrated. Caudal fin is always forked. There is one pair of maxillary barbels, sometimes having membranes and occasionally branched. The two pairs of mandibular barbels are often branched and can have nodes attached. The cone-shaped teeth in the upper jaw are short. S-shaped and movable in the lower jaw. These fish produce audible sounds when disturbed rubbing the base of the pectoral spine against the pectoral girdle. Body grayish to cuprous brown, lower body lighter. Scattered irregularly-shaped black spots on juvenile specimens, spots becoming slightly smaller in large specimens. Maxillary and mandibular barbels white, bases sometimes with scattered dusky pigmentation. Iris copper colored. Dorsal and pectoral –fin spines dark, terminating in short, light to dusky colored filaments. Anterior margin and ventral side of pectoral fin light colored. All rayed fins with black triangles at their base. Both lobes of caudal fin black, posterior margin white. Axillary pore absent; mandibular teeth 15-29; 8-9 pectoral-fin rays; premaxillary toothpad interrupted; Maxillary barbel with distinct basel membrane; secondary branches on medial mandibular barbels present; skin of body smooth. Adipose fin long well developed, margin convex. Humeral process narrow, elongated, granulous, weakly developed ridge on ventral margin, dorsal margin concave, terminating in rounded point.
General Remarks	An explanation as to why Synodontis irsacae has often been called S. dhonti in the past. Synodontis dhonti (Boulenger 1917) was described from a single specimen collected in 1912. Synodontis irsacae (Matthes, 1959) was placed in junior synonymy with S. dhonti by Matthes in 1962 with specimens of S. irsacae being thought to be juvenile individuals of S. dhonti. Wright & Page in 2006 put forth that none of these specimens have carried on any ontogenetic changes that would support the idea of S. irsacae being a juvenile form of S. dhonti. Mathes also cited a specimen n 1962 as being intermediate between the two species and this fish turned out to actually be a specimen of S. tanganaicae. Major differences separating S.irsacae from S. dhontibeing the absence of an axillary pore, retaining its spots and a smaller adult size.
Habitat Information
Distribution	Lake Tanganyika, common and widely distributed. African Waters , Western Rift Valley Lakes, Tanganyika (hover or click on these areas to show maps or find other species found there)
Husbandry Information
Feeding	Omnivorous, feeding on algae, sponges, ostracods, small crabs, insect larvae and fish eggs (Mathes 1959;Coulter1991a)
Furniture	In Lake Tanganyika inhabits littoral to benthic zones over shell, sand and mud bottoms.
Breeding	Unreported
Further Information
References	Wright, JJ and LM Page (2006) Taxonomic revision of Lake Taganyikan Synodontis (Siluriformes: Mochokidae). Florida Mus. Nat. Hist. Bull. 46(4):99-154.
Registered Keepers	(1) Dinyar, (2) Richard B (k: 2), who also notes: "Added a 5" individual - i am unsure if one is dhonti as although the differ in size by 3" they do appear different fish (?)". Click on a username above to see all that persons registered catfish species. You can also view all "my cats" data for this species. Add this species to your "my cats" page.
Breeding Reports	None.
More Resources	- Search Planet Catfish for more on Synodontis irsacae - BBcode (for use in linking to this page from forum posts) - Look up Synodontis irsacae on AquaticRepublic.com - Look up Synodontis irsacae on Fishbase, I.T.I.S. or ispecies search. - URL (for use in linking to the species from anywhere on the web)
Hits	4611 hits.
Last Update	2010 Oct 27 13:52 (species record created: 2002 Apr 12 00:00)

Cat-eLog Data Sheet

Scientific Name

Synodontis irsacae Matthes, 1959

Common Name(s)

None

Pronunciation

sin oh don tiss - er say see

Etymology

Synodontis: From the Greek syn, meaning together, and odontos, meaning tooth; in reference to the closely-spaced lower jaw teeth.

Species Information

Size

157mm (6.2") SL. Find near, nearer or same sized spp.

Identification

All species in the genus Synodontis have a hardened head cap that has attached a process (humeral process) which is situated behind the gill opening and pointed towards the posterior. The dorsal fin and pectoral fins have a hardened first ray which is serrated. Caudal fin is always forked. There is one pair of maxillary barbels, sometimes having membranes and occasionally branched. The two pairs of mandibular barbels are often branched and can have nodes attached. The cone-shaped teeth in the upper jaw are short. S-shaped and movable in the lower jaw. These fish produce audible sounds when disturbed rubbing the base of the pectoral spine against the pectoral girdle.

Body grayish to cuprous brown, lower body lighter. Scattered irregularly-shaped black spots on juvenile specimens, spots becoming slightly smaller in large specimens. Maxillary and mandibular barbels white, bases sometimes with scattered dusky pigmentation. Iris copper colored. Dorsal and pectoral –fin spines dark, terminating in short, light to dusky colored filaments. Anterior margin and ventral side of pectoral fin light colored. All rayed fins with black triangles at their base. Both lobes of caudal fin black, posterior margin white. Axillary pore absent; mandibular teeth 15-29; 8-9 pectoral-fin rays; premaxillary toothpad interrupted; Maxillary barbel with distinct basel membrane; secondary branches on medial mandibular barbels present; skin of body smooth. Adipose fin long well developed, margin convex. Humeral process narrow, elongated, granulous, weakly developed ridge on ventral margin, dorsal margin concave, terminating in rounded point.

General Remarks

An explanation as to why Synodontis irsacae has often been called S. dhonti in the past. Synodontis dhonti (Boulenger 1917) was described from a single specimen collected in 1912. Synodontis irsacae (Matthes, 1959) was placed in junior synonymy with S. dhonti by Matthes in 1962 with specimens of S. irsacae being thought to be juvenile individuals of S. dhonti.
Wright & Page in 2006 put forth that none of these specimens have carried on any ontogenetic changes that would support the idea of S. irsacae being a juvenile form of S. dhonti. Mathes also cited a specimen n 1962 as being intermediate between the two species and this fish turned out to actually be a specimen of S. tanganaicae. Major differences separating S.irsacae from S. dhontibeing the absence of an axillary pore, retaining its spots and a smaller adult size.

Habitat Information

Distribution

Lake Tanganyika, common and widely distributed.
African Waters Show it on a map

, Western Rift Valley Lakes, Tanganyika Show it on a map

(hover or click on these areas to show maps or find other species found there)

Husbandry Information

Feeding

Omnivorous, feeding on algae, sponges, ostracods, small crabs, insect larvae and fish eggs (Mathes 1959;Coulter1991a)

Furniture

In Lake Tanganyika inhabits littoral to benthic zones over shell, sand and mud bottoms.

Breeding

Unreported

Further Information

References

Wright, JJ and LM Page (2006) Taxonomic revision of Lake Taganyikan Synodontis (Siluriformes: Mochokidae). Florida Mus. Nat. Hist. Bull. 46(4):99-154.

Registered Keepers

(1) Dinyar, (2) Richard B (k: 2), who also notes: "Added a 5" individual - i am unsure if one is dhonti as although the differ in size by 3" they do appear different fish (?)".

Click on a username above to see all that persons registered catfish species. You can also view all "my cats" data for this species.

Add this species to your My Cats species list

Add this species to your "my cats" page.

Breeding Reports

None.

More Resources

- Search Planet Catfish for more on Synodontis irsacae
Link

- BBcode (for use in linking to this page from forum posts)
Look up AquaticRepublic.com

- Look up Synodontis irsacae on AquaticRepublic.com
Look up Fishbase

- Look up Synodontis irsacae on Fishbase, I.T.I.S. or ispecies search.
Link

- URL (for use in linking to the species from anywhere on the web)

Hits

4611 hits.

Last Update

2010 Oct 27 13:52 (species record created: 2002 Apr 12 00:00)

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