Paracanthopoma Giltay, 1935

Pinna, Mário de & Dagosta, Fernando Cesar Paiva, 2022, A taxonomic review of the vampire catfish genus Paracanthopoma Giltay, 1935 (Siluriformes, Trichomycteridae), with descriptions of nine new species and a revised diagnosis of the genus, Papéis Avulsos de Zoologia 62, pp. 1-90 : 8

Paracanthopoma Giltay

Paracanthopoma Giltay, 1935: 1

[type species: Paracanthopoma parva Giltay, 1935 , by original designation]

– Myers, 1944: 598 [key] – Gosline, 1945: 66 [catalogue] – Burgess, 1989: 324 [checklist] – Eschmeyer, 1990: 292 [catalog] – Eschmeyer, 1998: 2057 [catalog] – Spotte, 2002: 97 [historical account; summary of previously published information] – de Pinna & Wosiacki, 2003: 276 [checklist] – Ferraris, 2007: 410 [checklist].

Diagnosis: Paracanthopoma is distinguished from all other genera of Vandelliinae by the following putative synapomorphies:1 = presence of a branchiostegal velum across the isthmus ("free branchial membrane″ of previous authors); 2 = median premaxilla with dorsal bilateral flanges bracing lateral margins of mesethmoid neck; 3 = median premaxilla with narrow, well-defined posterior median recess; 4 = maxilla distally bifurcated (incipient in Pc.daemon ); 5 = posterior articular process of palatine directed straight posteriorly, parallel to neurocranium; 6 = anterior margin of palatine at articulation with premaxilla with deep indentation where a corresponding process of the premaxilla inserts;7 = coronoid process formed mostly or exclusively by the dentary, with anguloarticular portion reduced or absent; 8 = upper pharyngeal toothplate absent; 9 = articulation between neural arch of complex vertebra and supraoccipital limited to a small dorsomedial portion. Further distinguished from Vandellia and Plectrochilus by the scalpelloid teeth restricted to the distal tip of the premaxilla (vs. distributed along a long portion of the bone); by the post-articular process of anguloarticular large, pointed, directed straight laterally and projecting beyond lateral limits of anterior portion of suspensorium and jaw skeleton (vs. process inconspicuous, not projecting laterally); by the mesethmoid cornua lacking ventral bilateral processes at contact with premaxilla (vs. well-defined ventral process articulating with anterior process of premaxilla); by the skull roof mostly unossified (vs. skull roof entirely ossified); by the lack of a process on the ventral portion of the metapterygoid (vs. process present proximal to articulation with quadrate); by the presence of three or four branchiostegal rays (vs. five). Further distinguished from Paravandellia by the conical premaxillary teeth absent or few (one or two) (vs. conical teeth always present and four to nine in number); by the eyes located entirely dorsally on the head (vs. eyes located near the lateral margin of the head).

Geographic distribution: Species of Paracanthopoma are broadly distributed in the northern cis-Andean South American drainages, namely Amazon, Orinoco, and Essequibo, with a single locality also in the Upper Paraguay ( Fig. 2 ). They have not yet been recorded from large lowland Amazonian tributaries west of the mouth of the rio Negro, including the Japurá, Putumayo, Purus, and Juruá. Other notable absence include the rivers of the Guyana region between the Essequibo and the mouth of the Amazon (except for a single occurrence at rio Amapá Grande in Brazil).

Figures

Figure 2. Map of South America showing geographical distribution of Paracanthopoma.