The Chiloglanis thread

[Shane]

I am keeping several spp that I have collected and would like to start an ongoing discussion covering people's experiences with various species. A few things I have learned:

1) Diet; They are not algae eaters. In fact algae grows like crazy in their tanks if you let it (I did just to see if they would eat it). They like frozen foods and I am sure they would eat live foods if I had them. Those that have been in captivity longest appear to take small amounts of flake food. Gut content analysis show insect larvae and small amounts of algae. I believe the algae is ingested as a by product of snatching larvae from algae covered stones in nature.

2) Frequency of feeding; They need an incredible amount of food to stay fat. Twice daily feedings of large amounts appear necessary for optimal health. Jools, when he was collecting with me, noted the incredible density and diversity of aquatic larvae and insects in their habitat. A much higher density of food items than I have ever seen in a similar South or North American stream.

3) Aggressive feeding; They are not shy eaters. They will all come out of hiding and attack a chunk of floating frozen food right at the water's surface.

4) Fry feeding; The fry swim around the water's surface upside down eating whatever thy can find, including flake foods. The fry were all captured on the river's margins around vegetation. They must eat floating insects and debris this way in nature.

5)Temp; Average daily temps in the wild are in the low to mid 70s (21-22C), but if kept in well aerated clean water they can do well up to 80F (26.5C). It is high summer and I can not keep my tanks below the high 70s to 80F. The Chiloglanis are fine.

-Shane

[Richard B]

Hi Shane

Not much from me i'm afraid but here goes...

I have a single 2" Chiloganis - species unknown. It is kept in a small unlit (except for daylight)tank with power filtration & for tankmates there are a pair of phyllonemus typus & two Synodontis granulosus (2-3"). After an initial aclimatisation period it set up home underneath a four inch abalone shell and rarely ventures out in the day except for when food goes in - it is a ravenous little individual that feeds equally as well as the synos. Flakes, small grain pellet type foods & frozen bloodworm etc are eagerly consumed. it has not taken food from the water surface though. It shows no regard to the other fish in the tank even when competing for food.

I had a small (1-2") Atopochilus many years ago that i never saw until food was in the tank, although it waqs one of the last to react to the presence of food. However, it would try to nudge any other fish out of the way or chase them off & never failed - even if the other fish was massively bigger than it was.

Neither the chiloglanis or atopochilus touched algae & did show preferences for 'meaty' based food. The chiloglanis will greedily feed 2 or 3 times a day & the temperature is 80-82 as this tank is used as my quarantine tank.

All the best

Richard B

[lfinley58]

Hello Shane and all.

Shane, thank for starting this thread. Your experiences with these interesting mochokids are great to hear about and I will look forward to more.

I, like Richard, have found the Chiloglanis spp. that I have kept to be very good eaters of a wide variety of standardly offered aquarium foods.

I have made mention on this site before of a website that I am developing which will deal with the natural foods of catfish species (siluri-gut.net). For possible interest, I have included below the information that I currently have on various Chiloglanis species. Most of the information is based on what are generally called "snapshots". This is providing information on gut contents based on the examination of a single specimen or a few individuals of a given species. While these are limited in their scope, they can none-the-less provide valuable information in regards to the diet of a given species. As far as I am aware, at least to date, no long range (e.g. seasonal, yearly, etc.) studies of food habits have been performed on any Chiloglanis species.

One last note: In moving the data below to this post some of the various features (some formatting, italics for scientific names, etc.) were lost. I have previewed the post and it looks basically readable so I will forgo taking the time to make the numerous corrections in this area. Also, please excuse that some of this information is somewhat rough and still in need of editing. The references for each species are noted in the text, but are not included herein. If someone might be interested in a particular reference please PM me and I will be happy to furnish it.

Lee



Chiloglanis Peters, 1868

General considerations: Roberts (1989) states that members of this genus feed predominately on insects and attached algae. Roberts also provides a large amount of material (text and SEM photographs) on the teeth and taste buds of Chiloglanis.

Chiloglanis anoterus Crass, 1960

Skelton (2001) notes that this species grazes insects such as mayfly nymphs (Ephemeroptera) and blackfly larvae (Simuliidae) from rocks.

Chiloglanis asymetricaudalis De Vos, 1993

In the original description of this species De Vos (1993) makes note that G. Marlier, using the name C. lukugae, reported that this fish eats algae. The examination of the stomach contents of some specimens by De Vos showed the presence of insect larvae (not further qualified). Based on this it was noted that this species is probably an insectivore.

Chiloglanis batesii Boulenger, 1904

Under the name C. micropogon, the following items were reported in the gut of stream dwelling specimens from Western Cameroun: filamentous blue-green algae; rare diatoms; a small arthropod that was probably an ostracod (this has been feeding on the same algae eaten by the fish); and a segmented invertebrate (not further qualified) which was observed in the stomach of a cleared and stained individual. These observations led to the conclusion that this species feeds on algae (on stones) and the micro fauna that lives therein (Trewavas, 1974).

Chiloglanis bifurcus Jubb & Le Roux, 1969

Jubb and Le Roux (1969), in the original description of this species, note it to feed on algae and the associated macroinvertebrates (mainly insect larvae) found on rocks in its habitat. Some small empty mollusk shells were also seen in some specimens.
Skelton (1987, 2001) expanded on the insect component of the diet, noting that the larvae and nymphs of mayflies (Ephemeroptera), caddis flies (Trichoptera) are eaten in addition to the larvae of black flies (Simuliidae) and midges (chironomids). The small mollusk component of the diet was noted to be snails (gastropods).

Chiloglanis cameronensis Boulenger, 1904

Matthes (1964) noted the following items from the stomach of one fish from the Kululu River (Congo); sand, vegetal debris (especially small dead twigs), numerous small insect larvae (chironomids ? Simulium sp.).

Chiloglanis emarginatus Jubb & Le Roux, 1969

In the original description (Jubb and Le Roux, 1969) the gut of this species was noted to contain epiphytic algae and aquatic insect larvae. The type specimen was engorged with the larvae of Simulium sp. (black flies).
Additional food items that have been reported for this species include:
1. Ostracods and small molluscs (Skelton, 1987; Kleynhans, 1997).
2. Mayfly nymphs (Ephemeroptera) and the larvae of caddis flies (Trichoptera) and midges (chironomids) which are noted to be grazed from rocks (Skelton, 2001).

Chiloglanis fasciatus Pellegrin, 1936

This species feeds on small invertebrates (not qualified) and algae that are taken from both rock and plants (Skelton, 2001).

Chiloglanis microps Matthes, 1965

Matthes (1965) reported identifying the following stomach contents from this species: sand, some vegetal debris, occasional filamentous algae, scrapings from sponges, ostracods and large numbers of aquatic insect larvae (chironomids (Diptera), dragonfly (Odonata) and black flies (Simuliidae). Based on these results this species was considered to be an omnivore with a tendency towards carnivory.

Chiloglanis occidentalis Pellegrin, 1983

Daget (1954), using the name C. niloticus waterloti, briefly notes that this species feeds on algae.

Chiloglanis pretoriae Van der Horst, 1931

Skelton (2001) notes this species to feed on aquatic insects. Included are such items as mayfly nymphs (Ephemeroptera) and caddis flies (Trichoptera) and black fly (Simuliidae) larvae.

Chiloglanis sanagaensis Roberts, 1989

Although no specific food items were mentioned, Roberts (1989) does note that this species has long and highly coiled intestines. A specimen of 27 mm [presumed SL] was noted to have an intestinal length of slightly more than 30 mm. This was noted to be more than twice the relative length of that seen in C. batesii and some other species.

Chiloglanis somereni Whitehead, 1958

In the original description of this species Whitehead (1958) stated that the form of the mouth and the teeth suggest that it is a bottom feeder and grazer on algae. One examined stomach contained a light brown mass (most of which could not be identified) thought to probably represent epiphytic algae. Some diatoms were also observed. The fish was also noted to have a long and tightly coiled intestine.

Chiloglanis swierstrai Van der Horst, 1931

Bell-Cross, and Minshull (1988) state that this predominately sand dwelling species feeds on aquatic insects [larvae] such as midges (chironomids) and caddis flies (Trichoptera).
Skelton (2001) was more general in his diet description of this fish, noting only small invertebrates (not further qualified).

[Dinyar]

I kept a handful of Chiloglanis some years ago, and they were quite hardy once acclimatized. As observed by Shane and Lee, and previously by HH and others, they appear to rasp algae from the glass, but only become animated when foods like bloodworms hit the tank. I kept them for about a year before they succumbed to some passing pathogen.

I have also kept and still keep a half dozen Euchilichthys. Over the last three years, some have become quite big and fat. Like Chiloglanis, they obviously like meat, but they also graze -- to some limited extent -- on algae. Or maybe it's just that they're much bigger than Chiloglanis, so their algae grazing is more easily noticed.

[Shane]

Lee (and others),
Outstanding information. Of note to me is that all the spp mentioned from South Africa appear to be insectivores. There may well be algae eating spp from other parts of Africa, but they are not here.

I have been studying up on the info available and these animals are very difficult to identify to exact species even with collection data. Dentition is used in Jubb and Le Roux's key, but it is only a starting point as C. pretoriae and C. anoterus have the same dentition as do C. bifurcus and C. emarginatus. None of these spp are separated geographically, they are all described from the same (quite small) drainages. The above paper even states, "...it is not possible to separate female C. anoterus from C. pretoriae." Ok, then why are they two different spp? The distinction (remember they have the same dentition) is based on the shape of the caudal fin. Is this s different sp or simply a regional variation? Jubb and Le Roux also note that this difference in the caudal fin is sometimes "barely noticeable."
-Shane

[Shane]

A few updates,

These "suckers" can really climb!


Part of a day's catch


C. pretoriae dentition



-Shane