| Family: |
Trichomycteridae (Pencil or parasitic catfishes), subfamily: Microcambevinae |
| Max. size: |
3.08 cm SL (male/unsexed) |
| Environment: |
demersal; freshwater |
| Distribution: |
South America: Rio Gravataí basin, Laguna dos Patos system in Brazil. |
| Diagnosis: |
Anal soft rays: 7-8; Vertebrae: 45-46. Listrura depinnai can be readily diagnosed from other species of Listrura by the following putative autapomorphies: several spots on the region below the midline of the flank (vs. unpigmented in L. boticario, L. camposi, L.costai, and L. tetraradiata or with a slender row of small spots in L. nematopteryx and L. picinguabae); the caudal peduncle, including procurrent-ray folds, is deeper than the preanal portion of body (vs. approximately same depth); and a conspicuous intumescence adjacent to the posterodorsal margin of the pectoral-fin base (vs. swelling slight or absent). It shares the absence of a dorsal fin with L. boticario and the glanapterygines Glanapteryx, Pygidianops, and Typhlobelus, but can be readily separated from the former species by the features mentioned above and from the remaining genera by having a larger eye (9.0-10.5% HL vs. less than 6.0%, or absent) and a longer pectoral fin (11.1-11.6% SL vs. less than 5.0%, or absent). It further differs from all congeners, except L. tetraradiata, by having 45-46 vertebrae (vs. 48-55). It is further distinguished from L. tetraradiata by having 33-39 dorsal and 31-34 ventral procurrent caudal-fin rays (vs. 21-28 and 20-24, respectively), only unbranched rays on the anal and pectoral fins (vs. many branched rays), and the sensory pore of the sphenotic branch absent (vs. present). It differs further from L. costai, L. nematopteryx, and L. picinguabae by having 2 or 3 pectoral-fin rays (vs. one) and a slightly elongated, relatively deep body (body depth 12.2-12.7% SL vs. less than 10.5%); and from L. camposi by having all caudal elements almost entirely fused (vs. hypurals 1+2 not fused to hypurals 3+4+5) (Ref. 94748). |
| Biology: |
Found in a swamp with clear black water, mud and litter bottom, covered with a large amount of emerging vegetation adjacent to a dense and isolated fragment of wetland forest. Collected at a shallowsite (about 10 cm water depth above nearly 50 cm depth of submerged litter deposits) among the emerging vegetation. Other fishes captured in the same swamp include species of Cynopoecilus and Gymnotus aff. pantherinus, both are potentially new species (Ref. 94748). |
| IUCN Red List Status: |
Least Concern (LC); Date assessed: 07 November 2018 Ref. (130435)
|
| Threat to humans: |
harmless |
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