Isichthys henryi
to 235 mm SL
to 235 mm SL
demersal; freshwater; pH range: 5.0
License | http://creativecommons.org/licenses/by-nc/3.0/ |
Rights holder/Author | Tess Cruz, FishBase |
Source | http://www.fishbase.org/summary/SpeciesSummary.php?id=5077 |
EOD with two phases, an initial head-positive phase, followed by a head-negative phase. The overall duration is very long: 6.1-11.8 msec. There is a pronounced inflection point in the rising head-positive phase, leading to a sharp increase just before the first peak, P1. There is no initial head negativity. The electrocytes of the electric organ are non-penetrating and are innervated on the posterior surface (Type NPp).
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | Sullivan, John P., Hopkins, Carl D., Africhthy |
Source | http://mormyrids.lifedesks.org/pages/2095 |
The following is a representative barcode sequence, the centroid of all available sequences for this species.
No available public DNA sequences.
Download FASTA File
Barcode of Life Data Systems (BOLDS) Stats
Public Records: 1
Specimens with Barcodes: 1
Species With Barcodes: 1
Red List Criteria
Year Assessed
Assessor/s
Reviewer/s
Contributor/s
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | International Union for Conservation of Nature and Natural Resources |
Source | http://www.iucnredlist.org/apps/redlist/details/182624 |
Population
Population Trend
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | International Union for Conservation of Nature and Natural Resources |
Source | http://www.iucnredlist.org/apps/redlist/details/182624 |
Possesses electroreceptors over the entire head, the dorsal region and some parts of the ventral region; absent from the side and the caudal peduncle where the electric organ is located. Electric organ discharge (EOD) rates are of low frequency and sexually dimorphic as to waveform (Ref. 10011).
License | http://creativecommons.org/licenses/by-nc/3.0/ |
Rights holder/Author | Tess Cruz, FishBase |
Source | http://www.fishbase.org/summary/SpeciesSummary.php?id=5077 |
Major Threats
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | International Union for Conservation of Nature and Natural Resources |
Source | http://www.iucnredlist.org/apps/redlist/details/182624 |
Body very elongate, body depth 5.9-11.9% SL; cross-section slightly compressed laterally, about 70% as wide as deep. Unpaired fins long, dorsal base, 44-48% SL originating well in advance of anal. Anal base, 39-41% SL. Teeth large and bicuspid, five (rarely six) in upper jaw, six in lower. Head 1.75-2 times as long as deep. Snout bluntly rounded, 21-25% HL, mouth subterminal, opening directly below posterior nostril. Submental swelling present, but reduced, covered with electroreceptors. Four large Knollenorgan electroreceptors, with pore diameters equal to the posterior nostril, surround the eye. Eye small, less than 50% of snout length. Dorsal fin with 42-49 rays in rivers of Nigeria to the Ogowe (compared to 37-44 in the Upper Guinea populations). Anal fin with 40-48 rays in the populations from Niger to Ogowe compared to 36-44 for Upper Guinea. Caudal peduncle very small, its length only 8% SL; 1.7-3.3 times as long as high. Caudal fin small with obtusely pointed lobes. 120-140 scales in the lateral line with clinal variation from 135-145 in Upper Guinea to 120-130 in Lower Guinea; 16-20 circumpeduncular scales (circumpeduncular scales in Isichthys are sometimes irregular in shape and arrangement, leading to variable counts depending on where the counts are taken). Maximum size: 235 mm SL.
Coloration: uniformly dark chocolate-brown, yellow-brown on the head. Fin rays dark brown, membranes transparent.
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | Sullivan, John P., Sullivan, John P., Hopkins, Carl D., Africhthy |
Source | http://mormyrids.lifedesks.org/pages/2095 |
Least Concern (LC)
License | http://creativecommons.org/licenses/by-nc/3.0/ |
Rights holder/Author | Tess Cruz, FishBase |
Source | http://www.fishbase.org/summary/SpeciesSummary.php?id=5077 |