his month (July 2021) we have a collaboration with
the owner of AmazonTropics.com,
fish explorer and Auchenipteridae expert, Jeremy Basch.
We welcome his input on the former Tatia
species Centromochlus
heckelii and the
difficulties of keeping them in the home aquarium.
Mees in 1974 assigned this species to Tatia
but Ferraris in 2007 reverted it back to the original
genera of Centromochlus.
Centromochlus
heckelii
Two
features in both images are very obvious, the large
eyes and the also the large pectoral fins which are
always spread. The spines of the pectoral fins should
be handled with care as one can become stung by them,
and the spines also tend to tangle up in the mesh's
of a net when it is necessary to catch the fish. In
its natural habitat they are more active at dusk,
feeding mainly on insects and small crustaceans. They
stay sheltered in logs or crevices in rocks during
daytime, sometimes in small groups.
Centromochlus
heckelii
The family Auchenipteridae
consists of 26 genera and 126 species (Fricke et al.,
2020) divided into two subfamilies (Centromochlinae
and Auchenipterinae), which present some historical
internal phylogenetic incongruities (Ferraris, 1996;
Soares-Porto, 1998). This family gathers small to
medium size fishes, with suborbital groove to lodge
maxillary bone and anal fin of male with intromittent
organ (Calegari et al., 2019).
Auchenipterids
are inseminating fishes, a distinctive characteristic
also present in Astroblepidae and Scoloplacidae (Spadella
et al., 2006; 2012). Moreover, they also present internal
insemination and a remarkable sexual dimorphism related
to anal fin modification and other parts of the body,
such as dorsal and pelvic fins, and maxillary barbels
(Birindelli, 2014).
Between the two
subfamilies, Auchenipterinae has the highest species
richness, embracing 17 genera with 77 species (Fricke
et al., 2020), and Centromochlinae was composed of
eight genera and 49 species (Fricke , 2020). In the
recent phylogenetic study by Calegari et al. (2019),
Centromochlus Kner, 1858 was restricted to include
only Centromochlus heckelii (De Philippi,
1853) and Centromochlus existimatus Mees,
1974, both widely distributed species in the Orinoco
and Amazon basins (Soares-Porto, 1998; Ferraris, 2003,
2007; Akama, Sarmento-Soares, 2007). Centromochlinae
is a well-supported clade, and is diagnosed primarily
by traits associated to inseminating reproductive
system (Soares-Porto, 1998; Birindelli, 2014; Calegari.,
2019).
Distrbution: Map of the Amazon River drainage basin with
the Marañón River highlighted. Type
locality: Marañon River, upper
Amazon and Napo Rivers.
The Marañón River (Spanish: Río
Marañón, IPA: ['ri.o maa'on]) is the
principal or mainstem source of the Amazon River,
arising about 160 km to the northeast of Lima, Peru,
and flowing through a deeply eroded Andean valley
in a northwesterly direction, along the eastern
base of the Cordillera of the Andes, as far as 5°
36' southern latitude; from where it makes a great
bend to the northeast, and cuts through the jungle
Andes, until at the Pongo de Manseriche it flows
into the flat Amazon basin. Although historically,
the term "Marañon River" often
was applied to the river all the way to the Atlantic
Ocean, nowadays the Marañon River is generally
thought to end at the confluence with the Ucayali
River, after which most cartographers label the
ensuing waterway the Amazon River.
There is a report in scientific
works on the puncture wounds that are inflicted
on the natives along the Amazon River by species
of Centromochlus. In Brazil, as in much
of the world, puncture wounds caused by catfish
usually result from handling the netted or hooked
fish. The puncture wounds are sometimes aggravated
by the presence of venom glands in the skin sheath
that covers the sharp and often serrated spines
on the dorsal and pectoral fins of various catfish
species. The riverside people who inhabit the floodplain's
of Amazonian white water (turbid) rivers habitually
bucket bathe which they do several times a day and
most frequently at dusk. During bucket bathing,
the people are dressed (men in shorts, women in
frocks). For bathing, a person throws a bucket tied
to a rope into the river, pulls it out, and empties
it over him- or herself. At dusk and night the bucket
often collects small spiny driftwood catfish, Centromochlus
existimatus and Centromochlus heckelii
(Auchenipteridae) which the bather inadvertently
throws onto his or her body along with the water.
These spiny catfish have 3 well developed and sharp
spines with serrated edges, 1 in the dorsal fin
and 1 in each pectoral fin, which they spread out
and lock readily when frightened. This defensive
behavior may result in a catfish becoming attached
by its spines to several places on a bather’s
body (Sazima et .al.).
Remarks:
A little bit of history on our contributor Jeremy
Bash who is the proprietor of the web site AmazonTropics.com.
He houses over 100 aquariums ranging in size from
a few gallons to well over one hundred gallons!
AmazonTropics.com specializes in catfish of the
families, Loricariidae and Auchenipteridae from
South America. In fact, Jeremy was the first person
in the world to have Liosomadoras oncinus
spawn! He also maintains species from the families,
Callichthyidae and Aspredinidae. Along with catfish,
Jeremy also keeps some species of cichlids from
the family Cichlidae, the Geophaginae which include
Geophagus and Apistogramma. We
thank Jeremy for his input into this months factsheet.
Visit AmazonTropics.com.
South America:
Amazon and Orinoco River basins. Type locality:
Marañon River, upper Amazon and Napo Rivers.
Size:
14.0cm (5½ins)
Temp:
26-28°c (79-83°f.)
p.H.
6.5-7.5.
Characteristics
Adipose fin present, 5-8 branched
anal-fin rays; anal fin oblique relative to the body
axis in mature males; caudal peduncle oval in cross
section.
Colouration
Body with a uniform blue-grey
colour. They have a white underbelly. The dorsal
and caudal fins are dusky and dark.
Aquarium
Care & Compatibility
Jeremy states that unfortunately
this species constantly swims in the aquarium and
seems to be unable to detect the sides of the tank
so it's not really a good aquarium candidate as a
result. One might see better results in a tank with
a constant stream of water that goes across the tank.
This would require a fairly large pump or many jet
lifters. This species never goes and hides. They literally
swim 99% of the time. I'll occasionally see them resting
on the ground but it's uncommon.
Reproduction
Not reported.
Sexual
differences
Urogenital opening
at base of anteriormost anal-fin rays in mature males.
The sexes can be distinguished best by the shape of
the maxillary barbels, these barbels are curved in
males, straight in females.
Diet
In its native habitat they
feed on small invertebrates and crustaceans and in
the aquarium they will eat anything given such as
frozen bloodworm, catfish tablets, white worm (sparingly),
prawns and shrimp.
Glossary
of Terms
Anal fin:
The median, unpaired, ventrally located fin that lies
behind the anus, usually on the posterior half of
the fish. Caudal:The tail. Caudal peduncle: The narrow part
of a fish's body to which the caudal or tail fin is
attached. Dorsal fin: The primary rayed fin(s)
on top of the body. Maxillary Barbels: Pertaining to
the upper jaw. (maxillary barbels).
Etymology
Centromochlus:
Centrum = sting; mochlus = lever, from
ancient Greek "lever arm", referring to
the pectoral spines which can be a locked by a special
mechanism. heckelii:
In honour of Johann Jakob Heckel.
References
Basch,
Jeremy. AmazonTropics.com
pers. comm. 2021. Ferraris, C.J. Jr., 2007. Checklist
of catfishes, recent and fossil (Osteichthyes: Siluriformes),
and catalogue of siluriform primary types. Zootaxa
1418:1-628. Kowalski S, Paiz LM, da Silva M, Machado AS,
Feldberg E, Traldi JB, Margarido VP, Lui RL.
Chromosomal analysis of Centromochlus heckelii (Siluriformes:
Auchenipteridae), with a contribution to Centromochlus
definition. Neotrop Ichthyol. 2020; 18(3):e200009. Sazima, Ivan
PhD, BSc; Zuanon, Jansen PhD, BSc; Haddad Jr, Vidal
MD, PhD. Puncture Wounds by Driftwood Catfish During
Bucket Baths: Local Habits of Riverside People and
Fish Natural History in the Amazon. Sleen, van der Peter and Albert, S. James;
Field guide of the Amazon, Orinoco & Guianas.
Princeton University Press, Princeton and Oxford.
2018.
Soares-Porto, L.M., 1998. Monophyly and interrelationships
of the Centromochlinae (Siluriformes: Auchenipteridae).
p. 331-350. In L.R. Malabarba, R.E. Reis, R.P. Vari,
Z.M.S. Lucena and C.A.S. Lucena (eds.) Phylogeny and
classification of neotropical fishes. Porto Alegre:
EDIPUCRS. www.aquariumglaser.de
(Frank Schäfer). Wikipedia.org/wiki
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