Bunocephalus minerim, Carvalho & Cardoso & Friel & Reis, 2015

Carvalho, Tiago P., Cardoso, Alexandre R., Friel, John P. & Reis, Roberto E., 2015, Two new species of the banjo catfish Bunocephalus Kner (Siluriformes: Aspredinidae) from the upper and middle rio São Francisco basins, Brazil, Neotropical Ichthyology (Neotrop. Ichthyol.) 13 (3), pp. 499-512 : 505-509

Bunocephalus minerim , new species

urn:lsid:zoobank.org:act:41D3FB3D-FAF6-4894-A8C9-5EC56878B8FB

Figs. 5 , 6 , Table 1

Bunocephalus sp. N. 2. -Alves & Pompeu, 2005: 597 [listed as undescribed].

Bunocephalus sp. B. - Barbosa & Soares, 2009: 162 [listed].

Bunocephalus sp. - Leal et al., 2011: 148 [ecology]. -de Carvalho et al., 2011: 85 [barcoded].

Holotype. MCP 47087, 37.9 mm SL, Brazil, Minas Gerais, Guarda-Mor municipality, córrego Guarda-Mor, near the town of Guarda-Mor on highway BR-364, 17°44’52”S 47°05’40”W, 21 Jan 2012, R. E. Reis, E. H. L. Pereira & P. C. Lehmann A.

Paratypes. All from Minas Gerais, Brazil, rio São Francisco basin: ANSP 172080 , 1 , 24.4 mm SL, Curvelo municipality, rio Picão approx. 20 km NE of Curvelo, 18°36’14”S 44°17’06”W, 11 Jul 1993, S. A. Schaefer and others. MCP 16742, 1 , 36.8 mm SL, Curvelo municipality, rio Picão at road from Curvelo to Monjolos , 18°36’14”S 44°17’06”W, 11 Jul 1993, R. E. Reis, E. L. Pereira & S. A. Schaefer. MCP 28378, 1 , 45.3 mm SL, Paracatu municipality, stream at highway BR-040 from Paracatu to João Pinheiro, 17°18’15”S 46°46’16”W, 24 Jan 2001, C. A. S. Lucena, J. F. P. Silva, E. L. Pereira & A. R. Cardoso. MCP 28379, 2 c&s, 43.1-48.4 mm SL, Guarda-Mor municipality, córrego Macaúba tributary to rio Claro on road between Coromandel and Guarda-Mor, 17°58’57”S 47°06’41”W, 24 Jan 2001, C. Lucena, J. F. P. Silva, E. H. L. Pereira & A. R. Cardoso. MCP 34665, 3 (1 c&s), 29.8-32.9 mm SL, Iguatama municipality, ribeirão São Miguel tributary to rio São Francisco , 20°12’00”S 45°39’09”W, 26 Sep 2003, B. P. Nogueira. MCP 45156, 10 , 36.2-42 mm SL, Augusto de Lima municipality, rio Curimataí , tributary to rio das Velhas, 17°59’34”S 44°10’48”W, 9 Dec 2009, C. G. Leal & D. C. Carvalho. MCP 45242, 23 (2 c&s), 11.2-41.7 mm SL, Augusto de Lima municipality, rio Curimataí , tributary to rio das Velhas, 17°59’34”S 44°10’48”W, 9 Dec 2009, C. G. Leal & D. C. Carvalho. MCP 45759, 1 , 42.4 mm SL, Augusto de Lima municipality, rio Curimataí , tributary to rio das Velhas, 17°59’34”S 44°10’48”W, 24 May 2009, F. A. Sampaio, F. Suzuki & R. Couto. MCP 45763, 1 , 38.8 mm SL, Augusto de Lima municipality, rio Curimataí , tributary to rio das Velhas, 17°59’34”S 44°10’48”W, 24 May 2009, F. A. Sampaio, F. Suzuki & R. Couto. MNRJ 26500 , 3 , 30.6-36.6 mm SL, Iguatama municipality, rio São Miguel at Fazenda Doce de Leite , 20°11’59”S 45°39’09”W, 21 Dec 2003, B. P. Nogueira, G. A. Pereira & R. E. S. Hojo. MNRJ 31414 , 3 , 23.1-37.6 mm SL, Pains municipality, ribeirão Moendas, tributary to rio São Miguel , 20°26’31”S 45°40’00”W, 26 Aug 2007, P. A. Buckup, M. R. Britto & U. Jaramillo. MZUSP 39444 , 2 , 27.8-30.3 mm SL, rio Formoso , tributary to rio São Francisco , 8 Feb 1988, Y. Sato. MZUSP 73800 , 5 , 34.4- 42.4 mm SL, Augusto de Lima municipality, rio Curimataí at fazenda Vitória, 18°05’43”S 44°16’15”W, 16 Aug 2001, C. B. M. Alves & P. S. Pompeu. UFRGS 11273 , 2 , 40-40.9 mm SL, Unaí / Palmeirinha municipalities, stream at road between Unaí and Palmeirinha, 16°09’22”S 46°44’48”W, 11 Sep 2009, G. Frainer, F. R. Carvalho & V. A. Bertaco. UFRGS 11374 , 1 , fixed and preserved in ethanol 95%, 42.4 mm SL, Unaí / Palmeirinha municipality, stream at road between Unaí and Palmeirinha, 16°09’22”S 46°44’48”W, 11 Sep 2009, G. Frainer, F. R. Carvalho & V. A. Bertaco .

Sequences. Genseq-2 COI: Published sequences from a barcode study of the fauna of the São Francisco River basin (de Carvalho et al., 2011) identified as Bunocephalus sp. are available of paratypes MCP 45156, MCP 45763 and MCP 45759 . These correspond to genseq-2 COI following the nomenclature of Chakrabarty et al. (2013). GenBank accession numbers for these sequences are: HM405074 and HM405075 for MCP 45156 ; HM 405076 for MCP 45763 ; and HM 405077 for MCP 45759 .

Diagnosis. Bunocephalus minerim can be diagnosed from all congeners, except B. larai , by the absence of an epiphyseal bar between the paired frontals (vs. presence of the epiphyseal bar at least in adults). Bunocephalus minerim is distinguished from B. larai and other congeners, except B. chamaizelus , by having 9 principal caudal-fin rays (vs. 10 principal caudal-fin rays).

Description. Morphometric data summarized in Table 1 . Maximum body size small compared to congeners (maximum observed size 48.8 mm SL). Dorsal, left lateral and ventral views of body in Figs. 5-6 . Head and body depressed, lateral profile almost straight and ascending from supraoccipital tip to dorsal-fin origin, bony humps at posterior end of Weberian lamina and at middle nuchal plate. Posterodorsal profile of body straight and descending from origin of dorsal fin to caudal-fin base. Ventral body profile convex from mouth to insertion of pelvic fin; concave from this point to analfin origin, straight and ascending from anal-fin origin to base of caudal fin, slightly convex at caudal-fin base. Caudal peduncle slender, round in cross section, shallowest at midpoint between end of anal fin and caudal-fin origin.

Skull ornamentations weakly developed, conspicuous bony knobs absent in adult specimens. Eye small and positioned dorsolaterally. Skin covering eye dense and pale. Anterior nostril located terminally at tip of snout, associated with fleshy tube projecting beyond upper lip. Posterior nostril without flap, opening anteromedially near eye. Mouth subterminal, upper lip more prominent relative to lower lip. All barbels simple, unbranched, maxillary barbel slightly surpassing insertion of pectoral-fin spine, posterolateral mental barbel twice as long as anteromedial one. Opercular opening reduced to small valvular slit located just anterior and medially to insertion of pectoral- fin spine. Axial slit pore present, dorsoventrally inclined underneath posterior cleithral process. Some female specimens with eggs attached to lateral and ventral surface of the body and pectoral, pelvic and anal fins ( Fig. 6 ). Adult males with digitiform testes. Integument covered with small unculiferous tubercles, those on posterior portion of body larger and forming series of aligned longitudinal rows. Large and well-defined rows of tubercles on caudal peduncle, especially in juveniles, one on middorsum and three on lateral of body. Other rows poorly defined.

Osteological descriptions based on five cleared and stained specimens (32.6-47.6 mm SL). Anterior margin of mesethmoid straight, anterolateral projections absent. Ethmoid cartilage separate from articular facet of palatine. Frontal with lateral projections forming dorsal margin of eye. Frontal posteriorly projected laterally to posterior cranial fontanel and contacting supraoccipital, epiphiseal bar absent. Supratemporal fossa present at middle portion of contact between pterotic and supraoccipital bones. Pterotic with laterally expanded and pointed bony shelf. Premaxilla with somewhat rectangular shape, bearing teeth on its posteromedial margin. Dentary slender, abutting counterpart at medial portion, symphyseal portion slightly expanded, teeth present along most of dorsal margin of dentary. Ascending process of Meckel’s cartilage present, contacting main portion of this cartilage. Coronomeckelian bone present. Hyomandibula associated with preopercle and posterior portion of mandibular laterosensory canal, supraopercle absent. Cartilaginous contact of hyomandibula with neurocranium restricted to sphenotic bone. Anterodorsal process of hyomandibula developed, contacting ventral surface of sphenotic. Metapterygoid present (bilaterally absent in some specimens), small in size and ventrally contacting dorsal margin of quadrate. Endopterygoid present, somewhat squared in shape, located underneath contact of palatine and lateral ethmoid. Posterior margin of palatine cartilaginous and rounded. Opercle “L” shaped, posterior arm larger than ventral arm. Interopercle present, triangular in shape and firmly attached to ventral arm of opercle. Dorsal hypohyal absent. Anterior ceratohyal with expanded lamina on anteroventral margin, contacting posterior ceratohyal by means of cartilage and interdigitated suture. Posterior ceratohyal with foramen on midventral portion. Interhyal present. Typically five branchiostegal rays (four on one side in few specimens). Urohyal present, pointed anteriorly, without foramen. Lateral wings and dorsal keel of urohyal reduced or absent. First and second pharyngobranchials absent, third present and ossified, fourth present and variably ossified. First hypobranchial ossified, second variably ossified and third cartilaginous. Second basibranchial ossified, third variably ossified. Third epibranchial bearing uncinated process. Gill rakers absent on first and second branchial arches, small and scattered on third and fourth arches. Pharyngeal teeth well developed on upper tooth plate; about two rows of teeth on fifth ceratobranchial.

Dorsal lamina of Weberian complex reaching dorsal surface of body, lateral profile of lamina ascending posteriorly with anterior concavity and bony knob at middle portion ( Fig. 3b ). Parapophysis of fourth vertebra forming broad lamina over swim bladder presenting hookshaped process at posterior lateral margin. Parapophysis of fourth vertebra contacting parapophysis of fifth vertebrae extensively. Parapophysis of fifth vertebra long, extending to lateral body surface transverse to main body axis. Distal portion of fifth parapophysis expanded in adult specimens. Total vertebrae 34-37 (modally 34). Vertebrae bearing horizontal transverse processes from 7 th to penultimate centrum. Hemal spines simple, those contacting anal-fin pterygiophores not bifid.Four pairs of ribs,on vertebrae six to nine. Abdominal vertebrae foramina (hemal arches) for hemal canal on 6 th or 7 th and posteriorly on 11 th vertebrae.

Dorsal fin with four or five rays (modally five), without spinelet. First ray unbranched followed by three or four branched rays. About half length of last dorsal-fin ray adnate to dorsum by membrane. Anterior nuchal plate absent, middle nuchal plate contacting posterior nuchal plate laterally. Posterior nuchal plate not developed laterally, lateral extension passing slightly beyond contact with middle nuchal plate. Pectoral fin with one rigid spine and five branched soft rays, last one variably branched. Pectoral spine curved, bearing recurved serrations along ¾ of its anterior and posterior margins. Serrations increasing in number with larger body sizes, to maximum of 10 serrations on anterior and posterior margin of pectoral spines. A single ossified plus one cartilaginous pectoral-fin radial, one specimen with two ossified and one cartilaginous radial. Postcoracoid process of pectoral girdle extending slightly posterior to postcleithral process in lateral view. Pelvic fin with six soft rays, second and third rays longest, just reaching to anal-fin origin, first ray unbranched. Basipterygium with reniform shape, its posterior margin jagged and not bearing cartilaginous tip in adults. Lateral cartilage of basipterygium extending from anteriormost portion of bone to contact with last pelvic-fin ray. Anal fin with seven to nine rays (modally nine), first three to five unbranched. Caudal fin with nine principal rays, five associated with upper lobe and four with ventral lobe, posterior margin of caudal fin convex. Lowermost and uppermost principal caudal-fin rays unbranched with proximal expansion and slightly shorter than branched middle rays. Caudal fin with two procurrent rays on upper and lower lobes, anterior procurrent circular to rectangular in shape, posterior procurrent ray longer and spine-like. Posterior margin of upper hypural plate extending posteriorly further than lower hypural plate. Second ural half-centrum well-developed. Adipose fin absent.

Nasal canal ossified positioned laterally to mesethmoid, variably one or two tubular ossifications around canal. Antorbital present, with anterior limb pointed, extending anterior to anterior margin of premaxilla. Antorbital mesial limb rounded and associated with laterosensory canal. Infraorbital canal present with three tubular ossifications, canal exiting antorbital, passing below eye margin and entering neurocranium through sphenotic. Mandibular canal interrupted, with one tubular ossification lateral to posterior portion of dentary, and one or two tubular ossification near to contact with preopercle. Extrascapular present. Lateral line not associated with fourth parapophysis, anterior portion running just ventrally to margin of parapophysis. Lateral line complete; extending variably to caudal peduncle, with simple ossified tubes presenting variably few inconspicuous hooks on anterior portion.

Color in alcohol. Pigmentation variable with two distinct color morphs of overall dark and light patterns ( Figs. 6 a-b). Dark morph with dorsal portion of head and body dark brown with three poorly defined and variably present dark saddles, first beneath dorsal fin, second at vertical through middle of anal fin and third at end of caudal peduncle ( Fig. 5 ). Light morph have similar pigmentation pattern but with light brown dorsal surface contrasting with clearly defined dark brown saddles; lateral portion of body with irregularly mottled dark blotches ( Fig. 6a ). Ventral surface of body overall light brown with dark pigment concentrated in unculiferous tubercles. Pectoral, ventral and anal fins with scattered dark pigment. Dorsal and caudal fins overall dark with light distal portions. Caudal fin sometimes bearing clear patch at proximal portion.

Distribution. Known from several tributaries of the upper and middle rio São Francisco basins including the das Velhas, Formoso, Paraopeba and Paracatu rivers in Minas Gerais State, Brazil ( Fig. 4 ).

Etymology. The specific epithet, minerim , refers to the tipically regional manner of pronouncing the Portuguese word “mineirinho”, diminutive of “mineiro”, which refers to a person that comes from the State of Minas Gerais. The name is an allusion to the region where it is found and also to its relative small size in comparison with other species of Bunocephalus . A noun in apposition.

Conservation status. Bunocephalus minerim is known from an Extent of Occurrence (EOO) of approximately 75,000 km 2, and despite some areas within its range suffer continuing decline in habitat quality because of contamination from the city of Belo Horizonte and also mining and agriculture, there is no evidence of its habitat being severely fragmented or occurring extreme fluctuations in range or number of individuals. Considering that no specific threats to the species were detected, B. minerim is categorized as Least Concern (LC) according to the International Union for Conservation of Nature (IUCN) categories and criteria ( IUCN Standards and Petitions subcommittee, 2014).

Figures

Fig. 5. Bunocephalus minerim, MCP 47087, holotype, 37.9 mm SL, córrego Guarda-Mor near the town of Guarda-Mor on highway BR-364, Minas Gerais, Brazil.

Fig. 6. Paratype specimens of Bunocephalus minerim. a. Dorsal view of MCP 34665, 31.5 mm SL; showing the saddled pattern of a distinct color morph. b. Left lateral view of a mature female, MCP 45242, 41.4 mm SL, showing the eggs adhered and marks of previously attached eggs on the lateral and ventral portions of body and fins.

Fig. 3. Dorsal view of neurocranium and Weberian complex. a. Bunocephalus hartti, MNRJ 31385, paratype, 42.2 mm SL. b. Bunocephalus minerim, MCP 28379, paratype, 43.1 mm SL. ACF anterior cranial fontanel; EX, extrascapula; EP, epioccital; F, frontal; LAT, lateral ethmoid; SPH, sphenotic; SOC, supraoccipital; STF supratemporal fossa; SU, supracleithrum; PCF, posterior cranial fontanel; PTE, pterotic; VP4 parapophysis of fourth vertebra; and VP5 parapophysis of fifth vertebra. Scale bar = 5 mm.

Fig. 4. Distribution map of the new species of Bunocephalus in the rio São Francisco basin, Brazil. Circles represent Bunocephalus hartti and squares represent B. minerim, solid symbols indicate the type-localities.