Tenellus is a new
genus, described by Birindelli (2014) to include,
ternetziand the new species
N. cristinae. The snout is constricted, narrowly
compressed (gape very small); dorsal profile concave
between tip of snout and posterior nares.
Abstract: Tenellus cristinae is
described from the upper Amazonas/Solimões
and Madeira basins in Brazil, Colombia and Peru, with
additional specimens from the upper Meta (Orinoco
basin), Colombia, tentatively treated as conspecific.
Tenellus cristinae is distinguished from
congeners by having 3–9 premaxillary teeth in
approximately two rows in juveniles and adults, outermost
teeth weakly spatulate and innermost more acicular
(vs. premaxillary edentulous in adults of all congeners
and limited to 1–6 acicular teeth in juveniles
of N. elongatus, N. humeralis, T.
leporhinus and T. ternetzi); and mental
barbels with extremely elongate (filiform) papillae,
length of longest papillae about 4–7 times its
width at base (vs. papillae shorter, length of longest
<3 times its width at base). Tennelus cristinae
most closely resembles T. leporhinus, but
is further distinguished from that species by having
shaft and primary fimbriae of maxillary barbel smooth
(vs. outer margin of shaft and margins of primary
fimbriae with distinct secondary fimbriae). Nuptial
specimens of T. cristinae exhibit sexual
dimorphism; in males the pungent dorsal spine is greatly
prolonged by a soft, flexible tip approximately 19.8–23.9%
of the total dorsal spine length (vs. 5.3–9.4%
in females). The sturdy, spatulate teeth in the upper
and lower jaws of T. cristinae are evidently
effective tools for raking caddisfly larvae from their
attached substrates, as gut contents were dominated
by cases and larval remnants of Nectopsyche (Leptoceridae).
Aquarium Care: Best kept in groups
in a large aquarium as they will not do well singularly.
Avoid boisterous or aggressive tankmates as this is
a shy species that will hide out during the day and
appear for food at night under darkness. Provide a
dimly lit tank with floating plants. Diet:
Tubifex, Daphnia, Cyclops. Once
settled in they will take frozen foods, flake and
tablet foods. Etymology: Tenellus
comes from the Latin tener, meaning delicate, in reference
to the delicate appearance of those dorads. cristinae
is named after the main author's wife, Cristina Sabaj
In most online publications the synonym of Nemadoras
cristinae is still being used for this species.
Amazonas/Solimões and Madeira basins in Brazil,
Colombia and Peru.
Birindelli, J. L. O.
2014 (16 Sept.) Phylogenetic relationships of the
South American Doradoidea (Ostariophysi: Siluriformes).
Neotropical Ichthyology v. 12 (no. 3): 451-563 [1-102]. Mark H. Sabaj Pérez,
Mariangeles Arce H, Leandro M. Sousa and José
L. O. Birindelli;
Nemadoras cristinae, new species of thorny catfish
(Siluriformes: Doradidae) with redescriptions of its
congeners. Proceedings of the Academy of Natural Sciences
of Philadelphia 163(1):133-178. 2014.