Listrura camposi ( Miranda-Ribeiro, 1957 )

Villa-Verde, Leandro, Lima, Sergio M. Q., Carvalho, Pedro Hollanda & de Pinna, Mário C. C., 2013, Rediscovery, taxonomic and conservation status of the threatened catfish Listrura camposi (Miranda-Ribeiro) (Siluriformes: Trichomycteridae), Neotropical Ichthyology 11 (1), pp. 55-64 : 56-61

Listrura camposi ( Miranda-Ribeiro, 1957) Figs. 1-2

Eremophilus camposi Miranda-Ribeiro, 1957: 72 , fig. Type locality: ribeirão do Poço Grande, tributary to the right bank of rio Juquiá, itself tributary to rio Ribeira, Fazenda Poço Grande, município de Juquiá, São Paulo State, Brazil [ca. 24°15’S 47°37’W], holotype MZUSP 3426.- Miranda-Ribeiro, 1962: 1-2, fig. [non Miranda-Ribeiro, 1957; actually Listrura nematopteryx ].- Britski, 1969: 206 [Type catalog].- de Pinna, 1988: 119 [remarks; synonymy].

Listrura camposi .- de Pinna, 1988: 119, figs. 3, 4 [redescription; phylogenetic relationships; inclusion in Glanapteryginae].- Bizerril, 1994: 625 [distribution].- Nico & de Pinna, 1996: 29 [distribution; habitat notes].- Burgess & Finley, 1996: 168 [checklist; distribution].- Landim & Costa, 2002: 154- 155 [phylogenetic relationships].- de Pinna & Wosiacki, 2002: 725 [phylogenetic relationships].- de Pinna & Wosiacki, 2003: 275 [checklist; distribution].- Rosa & Lima, 2005: 81 [checklist; conservation status].- Villa-Verde & Costa, 2006: 44 [distribution].- Menezes et al., 2007: 306, fig. [checklist; distribution; conservation status].- Wosiacki & de Pinna, 2007: 74 [checklist; distribution; conservation status].- Ferraris Jr., 2007: 408 [checklist; distribution].- Rosa & Lima, 2008: 243-244, fig. [checklist; conservation status; distribution; habitat notes].- Adriaens et al., 2010: 350 [trichomycterid morphology].- Datovo & Bockmann, 2010: 219-221, table 2, figs. 31, 32 [phylogenetic relationships].- de Pinna & Kirovsky, 2011: 502 [comparative material].- Villa-Verde et al., 2012: 534 [comparative material].

Listrura campos .- MMA, 2004: 141 [misspelling; conservation status].

Diagnosis. Listrura camposi is distinguished from all congeners by the quadrate bone with an abrupt depression on dorsal margin (vs. depression absent or very slight; Fig. 3 ), and the presence of a vestigial neural arch on the compound caudal centrum (vs. absent; Fig. 4 ). It differs further from L. tetraradiata Landim & Costa in having only unbranched rays on the dorsal, anal and pectoral fins (vs. some branched rays present in each of those fins), by the presence of 30-34 dorsal and 26-28 ventral procurrent caudal-fin rays (vs. 21-28 and 20-24, respectively), 49-51 total vertebrae (vs. 44-45), and absence of supraorbital canal and respective pore on the laterosensory system (vs. present). Differs further from L. nematopteryx , L. costai Villa-Verde, Lazzarotto & Lima and L. picinguabae Villa-Verde & Costa by having three or four (rarely two) pectoral-fin rays (vs. one), and caudal skeleton with hypurals 1+2 and hypurals 3+4+5 separate (vs. almost entirely fused; Fig. 4 ). Differs further from L. boticario de Pinna & Wosiacki by the presence of dorsal fin (vs. absent).

Description. Morphometric data given in Table 1. Body elongate, subcylindrical at anterior portion of trunk, strongly compressed at caudal peduncle. Dorsal and ventral profiles straight. Skin papillae minute.

Head depressed and trapezoidal. Snout blunt and slightly elongate. Mouth subterminal and narrow. Teeth conical, tips pointed and curved. Two rows of teeth in jaw. Premaxillary teeth 18-26; dentary teeth 17-21. Eyes anteriorly located on head, nearer snout tip than to opercular patch of odontodes. Nasal, maxillary and rictal barbels well developed. Tip of nasal barbel reaching between posterior margin of interopercular patch of odontodes and posterior margin of opercular patch of odontodes. Tip of maxillary barbel reaching just beyond posterior margin of opercular patch of odontodes. Tip of rictal barbel reaching between middle of interopercular patch of odontodes and posterior margin of opercular patch of odontodes. Anterior nostril anteriorly at base of nasal barbel. Posterior nostril on anterior half of length between anterior nostril and eye. Interopercular odontodes 11-15, opercular odontodes 8-10; odontodes conical, tips pointed and slightly curved.

Dorsal and anal fins approximately triangular, all rays unbranched. Dorsal-fin origin on posterior half of trunk, at vertical between centra of 32 nd and 33 th vertebrae. Anal-fin origin at vertical between centra of 33 rd and 34 th vertebrae, and at vertical through 4 th to 6 th dorsal-fin ray. Posterior margin of caudal fin rounded; caudal fin extending dorsally and ventrally to posterior margins of dorsal- and anal-fin bases. Pectoral fin triangular; first ray filamentous. Pelvic fin and girdle absent. Dorsal-fin rays 8. Anal-fin rays 8-9. Principal caudal-fin rays 12, dorsal procurrent rays 31-34, ventral procurrent rays 26-28. Pectoral-fin rays 3/2 (3), 3/3 (28), 3/4 (10), or 4/4 (8); holotype 3/3. Ribs 3-4. Total vertebrae 49-51. Branchial membranes attached only at anteriormost point of isthmus. Branchiostegal rays 6.

Laterosensory system extremely reduced, without supraorbital, infraorbital, and otic canals. Preopercular canal extremely reduced to single pore, at vertical through anterior margin of opercular patch of odontodes ( Fig. 5a ). Postotic canal with one pore, corresponding to pterotic branch, at vertical just posterior to opercular patch of odontodes. Main lateral line short, with two pores: anteriormost largest, at vertical just posterior to pectoral-fin base; posteriormost below and just posterior to first pore.

Osteology. Anterior cornua of mesethmoid straight ( Fig. 5a ). Lateral ethmoid with small lateral projection. Frontal triangular; cranial fontanel absent. Parieto-supraoccipital with lateral processes enclosed to sphenotic. Prootic, pterosphenoid and sphenotic entirely fused to each other. Vomer without posterior process (bottle-shaped). Parasphenoid with small posterior process, reaching to anteriormost tip of basioccipital. Pterotic with lateral laminar expansion. Basioccipital and exoccipital fully fused to each other and posteriorly fused to Weberian capsule. Co-ossified basioccipital and exoccipital approximately triangular. Weberian capsule with small lateral opening to each side.

Autopalatine nearly square with dorsally-curved posterolateral process ( Fig. 5a ). Premaxilla triangular. Maxilla elongate. Antorbital short and club-shape. Sesamoid supraorbital extremely reduced.

Dentary triangular with teeth reaching half distance between coronoid process and mesial tip ( Fig. 5b ). Meckel cartilage square; extension of area in contact with dentary similar to that in contact with angulo-articular (see Discussion below). Angulo-articular and retro-articular entirely fused. Coronoid process with large cartilage on dentary portion (coronomaxillar cartilage, following Datovo & Bockmann, 2010).

Hyomandibula with elongated and narrow anteriororiented process ( Fig. 3 ). Quadrate elongate with anterodorsal laminar projection and with abrupt depression on dorsal margin forming U-shape (see Discussion below). Metapterygoid very reduced and articulating only with anterodorsal portion of quadrate through cartilaginous block. Preopercle elongate. Opercular odontodes disposed on vertical plane at posteriormost process of opercle. Interopercular odontodes disposed obliquely on posterior tip of interopercle, far behind from articular condyle for preopercle (see Discussion below).

Basibranchial 1 absent ( Fig. 5c ). Basibranchials 2 and 3 cylindrical, interconnected by cartilages.Anteriormost border of basibranchial 2 and posteriormost border of basibranchial 3 with respective cartilages. Basibranchial 4 flattened and fully cartilaginous. Hypobranchial 1 cylindrical. Hypobranchials 2 and 3 flattened and cartilaginous with triangular anterolateral ossified process. Hypobranchial 4 absent. Ceratobranchials 1, 2, 3, and 4 cylindrical, with slight posterior laminar process. Ceratobranchial 5 with posterodorsally-oriented conical teeth on anterior half of mesial margin. All ceratobranchials with cartilages on tips, except ceratobranchial 5 without cartilage on posterior tip. Epibranchials 1, 2, and 3 thin; first and second with anterior and posterior processes, respectively, and third with curved posterior uncinate process. Epibranchial 4 cylindrical with large laminar process on posterior margin. Epibranchial 5 absent. Pharyngobranchials 1 and 2 absent. Pharyngobranchial 3 cylindrical. Pharyngobranchial 4 fully cartilaginous and fastened to tooth plate. Upper pharyngeal tooth plate with long ventromedially-oriented conical teeth.

Parurohyal with narrow pointed and elongated lateral processes reaching to posterior tip of anterior ceratohyal ( Fig. 5d ). Two small condyles on anterior region of parurohyal. Deep depression on ventral hypohyal for articulation with parurohyal condyle. Anterior ceratohyal cylindrical and constricted on central region. Posterior ceratohyal nearly triangular. Interceratohyal cartilage expanded on portion of branchiostegal rays.

Cleithrum flattened, slightly triangular and with large decalcified central region ( Fig. 5e ). Scapulocoracoid fully cartilaginous. Proximal radial 1 rounded and proximal radial 2 elongate; both fully cartilaginous.

Caudal skeleton partly compact ( Fig. 4 ). Parhypural and hypurals 1-2 fused. Hypurals 1-2 and Hypurals 3-5 separated. Uroneural entirely fused to compound centrum. Preural 1- ural 1 compound with vestigial neural arch.

Color in alcohol. Dorsal half of trunk and caudal peduncle with irregular or roundish, partly coalescent, dark marks ( Fig. 1 ). Marks darkest and densest along lateral midline, forming longitudinal stripe extending from posterior margin of head to beginning of caudal peduncle; in some specimens extending posteriorly onto part or whole of caudal peduncle as fine line. Midlateral dark stripe nearly continuous in some specimens, interrupted as series of individual dark spots in others. Myomeres on caudal peduncle partly and irregularly outlined by slanted dark lines. Ventral part of flank and abdomen white or with few scattered dark spots, denser posteriorly. Pectoral fin white or with faint dark streaks dorsally along margin of first ray. Dark concentration alongside base of anal fin, forming short dark band in some specimens. Remainder of anal fin without dark pigment. Region of procurrent caudal-fin rays with sparse dark fields, denser on dorsal series. Caudal fin with elongate dark fields on central portions of principal rays, forming spotted pattern or faint irregular vertical stripes. Dorsal surface of head with irregular covering of semicoalesced dark marks ( Fig. 2a ). Marks densest on snout, especially around posterior nostrils, extending posteroventrally onto base of both opercular and interopercular patches of odontodes. Some specimens with pigment on snout uniform. Region of neurocranium darker than rest of head, due mostly to brain pigment seen by transparency. White or less darkly-pigmented area ventrolateral to eye. Margins of posterior nostrils and sensory pores finely delineated in white. Basal portion of maxillary barbel with elongate scattering of dark chromatophores along dorsal surface of anterior margin; ventral surface with sparse dark fields near base. Similar pattern of dark pigmentation on nasal and rictal barbels, but faintest on latter. Ventral side of head less darkly pigmented than dorsal surface, with irregular field of dark chromatophores over mental region, extending in curved paths posteriorly along bases of branchiostegal rays and then ventrally joining dark covering of interopercular patch of odontodes ( Fig. 2b ). Lower lip white, with dark spot at symphysis in some specimens.

Color in life. Entire ground color of body and head yellowish, slightly reddish on branchial region and alongside ventral part of vertebral column due to blood seen by transparency ( Fig. 1 ). Dark brain pigment more visibly pronounced than in preserved specimens, probably due to increased transparency of integument in life. Fins mostly hyaline. Dark pigmentation otherwise similar to that in preservative (see above).

Distribution and habitat notes. Listrura camposi is known to occur in two small streams tributaries to rio Juquiá, rio Ribeira de Iguape basin, São Paulo State: ribeirão Poço Grande, município de Juquiá (type locality), and a tributary to rio Itariri, município de Pedro de Toledo ( Fig. 6 ). Approximately 37 km separate the two localities. However, the area of the type locality is presently much degraded, due to intense human activity in the region (O.T. Oyakawa, pers. comm.; MCCP, pers. obs.), and there seems to be little hope of any surviving populations of L. camposi there.

The specimens of Listrura camposi from the tributary to the rio Itariri were collected in a narrow (about 1 m wide) and shallow (about 10 cm deep) clear-water pool contiguous to the stream, covered with a dense layer of leaf litter on bottom ( Fig. 7 ) and crossing under a small road before joining the rio Itariri. Although the mountain slope is covered with dense Atlantic forest, a great portion of the stream in the lowland plain area, where most of the L. camposi specimens were caught, is devoid of riparian protection. Individuals were concentrated on the stretch immediately below the steepslope portion of the stream. The species seems to be restricted to the interface between the fast-flowing, high energy sector and the lowland slow-current portion of the stream. Some specimens were captured in a small pool just within the fast-flowing sector, in a dense layer of leaf litter, but none in similar pools further upstream. Specimens were captured mostly in leaf litter in shaded areas and amidst roots of emerging vegetation in sand-clay substrate, in sun-exposed areas.

Listrura camposi specimens are locally abundant, although their area of occupancy is extremely restricted, with the stream and the contiguous pool in this stretch not exceeding 50 m 2. Gymnotus pantherinus (Steindachner) , Hollandichthys multifasciatus (Eigenmann & Norris) , and Atlantirivulus santensis (Köhler) were the only fishes collected with L. camposi . Copepods, insect larvae and mites were found on stomach contents of some CS specimens, as previously observed for L. tetraradiata by Landim & Costa (2002).

Material examined. Brazil. São Paulo State. MZUSP 3426 , holotype, 38.0 mm SL, município de Juquiá, ribeirão Poço Grande, tributary to right margin of rio Juquiá, itself tributary to rio Ribeira, rio Ribeira de Iguape basin, approximately 24°15’S 47º37’W . MNRJ 37023 , 6 (2 CS), 29.6-43.4 mm SL ; MNRJ 33031 , 18 (1 CS), 28.4- 50.0 mm SL; and MZUSP 95189 , 25 (2 CS), 20.7-46.4 mm SL, município de Pedro de Toledo, small stream tributary to rio Itariri, itself tributary to rio Juquiá, rio Ribeira de Iguape basin, just upstream from small road near to protected area “Parque Estadual da Serra do Mar - Núcleo Pedro de Toledo”, 24°15’06.4”S 47º14’53.3”W .

Figures

Fig. 1. Listrura camposi, MZUSP 95189, 46.4 mm SL, live specimen; Brazil, São Paulo State, município de Pedro de Toledo. Photo by Cristiano Moreira.

Fig. 2. Head detail of Listrura camposi, MZUSP 95189, 46.4 mm SL in (a) dorsal and (b) ventral views.

Fig. 3. Suspensorium and opercular apparatus of Listrura camposi, MNRJ 37023, 35.7 mm SL, left side: lateral view. Dashed lines indicate the inclination of the opercular and interopercular paths of odontodes. Legends: HY - hyomandibula, IO - interopercle, MT - metapterygoid, OP - opercle, PO - preopercle, QU - quadrate.

Fig. 4. Caudal skeleton of Listrura camposi, MNRJ 37023, 35.7 mm SL, left side: lateral view. The arrow indicates the vestigial neural arch of preural-1 centrum. Legends: H3+H4+H5 - fused hypural 3-hypural 4-hypural 5, HS - hemal spine, NS - neural spine, P1+U1 - fused preural 1-ural 1, P2 - preural centrum 2, PH+H1+H2 - fused parhypural -hypural 1- hypural 2, UN - uroneural.

Fig. 5. Skeleton of Listrura camposi, MNRJ 37023, 35.7 mm SL. (a) Skull and Weberian capsule in dorsal (left) and ventral (right) views.(b) Lower jaw, left side; internal view.(c) Gill arches, dorsal view. Right dorsal elements not drawn. (d) Hyoid arch, left side: ventral view. Dashed lines indicate the tip of the lateral process of parurohyal in relation to ceratohyals. (e) Pectoral girdle, left side: ventral view. Legends:AA+RA - angulo-articular and retro-articular co-ossified,AC - anterior ceratohyal, AN - antorbital,AU - autopalatine, B2-4 - basibranchials 2 to 4, BA+EX - fused basioccipital-exoccipitals, BR - branchiostegal rays, C1-5 - ceratobranchials 1 to 5, CL - cleithrum, cpr - coronoid process, DE - dentary, E1-4 - epibranchials 1 to 4, EP - epioccipital, FR - frontal, H1-4 - hypobranchials 1 to 4, IC - interceratohyal cartilage, LE - lateral ethmoid, ll1-2 - pores 1 and 2 of main lateral line, MA - maxilla, MC - Meckel cartilage, ME - mesethmoid, OB - orbitosphenoid, P3-4 - pharyngobranchials 3 and 4, PA - parasphenoid, PC - posterior ceratohyal, PF - pectoral-fin rays, PM - premaxilla, PP - “posttemporosupracleithrum”, pp1 - pore 1 of preopercular canal, po1 - pore 1 of postotic canal, PT - pterotic, PR1-2 - proximal radials 1 and 2, RA - retro-articular, SC - scapulocoracoid, SO - sesamoid supraorbital, SP+PO+PS - fused sphenotic-prootic-pterosphenoid, SU - parieto-supraoccipital, TP - tooth plate, UH - parurohyal, VH - ventral hypohyal, VO - vomer, WE - Weberian capsule.

Fig. 6. Geographic distribution of Listrura camposi (circles) and Listrura sp. (square) from município de Florianópolis; Southeastern Brazil, Santa Catarina to São Paulo States. Open circle indicates the type locality of L. camposi.

Fig. 7. Photograph of small stream tributary to rio Itariri, itself tributary to rio Juquiá, rio Ribeira de Iguape basin, 24°15’06.4”S 47º14’53.3”W, locality of the newly-discovered population of Listrura camposi.