Hisonotus aky
(Azpelicueta, Casciotta, Almirón & Koerber, 2004)
|
t is the month of October 2018 and the topic is a small member
of the Loricariidae family and one of the most stunning discoveries
of the last 14 years namely the "Green Oto" Hisonotus
aky. This fish caused quite a stir in the hobby
when first described and all these years later it has now been
bred in the hobby.
Hisonotus aky
(Azpelicueta, Casciotta, Almirón & Körber, 2004)
was originally described in Epactionotus Reis &
Schaefer, 1998 because of its supposed possession of three synapomorphies
proposed for that genus: neural spine of seventh vertebra not
contacting nuchal plate dorsally (contacting unpaired predorsal
plates), first dorsal proximal radial contacting the eighth
vertebral centrum, and absence of an expanded fleshy flap on
the dorsal surface of the first pelvic-fin ray in males. Also,
Hisonotus aky possesses one of the additional diagnostic
characters of Epactionotus: longitudinal light stripes
on dorsal surface of head. However, the examination of type
specimens of Epactionotus aky indicates the absence
of most diagnostic features for the genus.
|
Hisonotus
aky - three day
old fry |
This species has been bred by English
aquarist Paul Dixon from the Bolton Museum, England and is shown
above.
According to Evers et al, they
are only found in a small area in the Rio Uruguay drainage in
the Fortaleza Creek, close to the city of Paraiso.
A very unique species, in that it can
be easily recognised by its overall green body colour, although
freshly imported specimens are often olive coloured and do not
show the bright metallic green colouring until well settled.
The following summary is from AZPELLICUETA
et al (2004). Epactionotus (Hisonotus) aky is
diagnosed by the following combination of characters: 1) 21 to 23
lateral plates; 2) light stripes extended from snout tip to supraoccipital
level; 3) caudal fin with dark vertical stripes; 4) ventral surface
of body completely covered by small platelets; 5) 1-4 feeble serrae
on distal portion of pectoral spine posterior margin.
Green body colouration
although freshly imported specimens are often olive coloured and
do not show the bright metallic green colouring until well settled.
| Aquarium
Care |
They rest on aquatic
vegetation in the aquarium and the less light in the tank
the darker they become. Provide a current in your tank for
this species as they come from swift flowing waters. A sandy
substrate is best with smooth rocks and pieces of bogwood,
with thickets of broad-leaved plants such as Amazon swords.
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| Compatibility |
Peaceful fish with other companions who
like water movement in the aquaria.
They lay their eggs on plant leaves
| Sexual
differences |
Females grow a bit larger
than the males. The males usually are not as strong in colouration
and have longer fins.
|
| Feeding |
Will feed on flake, algae, tablet foods,
algae wafers and insect based foods.
| Glossary
of Terms |
Lateral:
A sensory line, along the sides of the body.
Nuchal: Area between the skull and dorsal
fin.
Dorsal: The primary rayed fin(s) on top
of the body.
Pelvic fins: The paired fins, between the
pectorals and the anal fins. (also referred to as ventrals).
Supraoccipital: Unpaired bone at the back
of the skull, usually with a crest.
Caudal fin: The tail.
Pectorals: The paired fins just behind
the head.
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| Etymology |
Hisnotus:
Greek, isos = equal + Greek, noton = back
|
| References |
Evers, H.-G. &
I.Seidel: Mergus, Baensch
Catfish Atlas Volume 1, 1st English edn., 2005. Pp.944.
Ferraris, C.J. Jr., 2007. Checklist of catfishes,
recent and fossil (Osteichthyes: Siluriformes), and catalogue
of siluriform primary types. Zootaxa 1418:1-628.
Azpellicueta, Casciotta, Almiron, & S. Korber,
2004, A new species of Otothyrini (Siluriformes: Loricariidae:
Hypoptopomatinae) from the Río Uruguay basin, Argentina.
Tiago Pinto Carvalho; The species of Hisonotus
(Siluriformes: Loricariidae: Hypoptopomatinae) of the Rio
Uruguay basin, southeastern South America in: A new species
of Hisonotus (Siluriformes: Loricariidae: Hypoptopomatinae)
from the Laguna dos Patos Basin, Southern Brazil.
Fuller, Ian.
https://www.practicalfishkeeping.co.uk/features/articles/green-oto-epactionotus-aky
www.l-welse.com/reviewpost/showproduct.php/product/1228/cat/105
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| Photo
Credits |
Top: ©
Ingo Seidel @ 
Bottom: ©
Paul Dixon @ |
|
|
| Synonyms:
|
| Epactionotus
aky |
| Common
Name: |
| Green Oto |
| Family: |
| Loricariidae |
| Subfamily: |
Hypoptopomatinae |
| Distribution: |
| Argentina:
Yabotí-Guazú basin, Uruguay River system, Misiones.
Type locality: Argentina, Misiones, Río
Uruguay basin, Arroyo Garibaldi (26º38'46.1"S, 53º59'55"W).
|
| Size: |
| 4.5cm. (1¾ins) |
| Temp: |
| 18-24°c (63-75°f.) |
| pH.: |
| 6.5 -7.2. |
| Donation: |
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