Leptodoras cataniai, Sabaj, 2005

Sabaj, Mark Henry, 2005, Taxonomic assessment of Leptodoras (Siluriformes: Doradidae) with descriptions of three new species, Neotropical Ichthyology 3 (4), pp. 637-678 : 667-671

Leptodoras cataniai , new species

Figs. 4g , 5g , 6b , 18e and 22

Holotype. ANSP 180918 (1*, 171 mm), Venezuela, Amazonas, río Casiquiare from mouth of río Pamoni to 4 km below mouth, west of Pamoni (2°48’N, 65°57’W), 17 Mar 1987, B. Chernoff, O. Castillo and C. Garrido, V87-27 .

Paratypes (28). Brazil: Amazonas : ANSP 131431 (1*, 110.6 mm), west of Moura, near junction of rio Negro and rio Branco (1°30’S, 61°48’W), Apr 1967 ; MCZ 101046 (8), rio Negro (Amazonas dr.), Ilha de Jacaré , 1991 . Venezuela: Amazonas: AMNH 236111 (1, 151 mm) , ANSP 161532 (5 + 1*, 146.5 mm), same data as holotype ; ANSP 161533 (2, 145.5- 173.3 mm), río Casiquiare, main channel ca. 1.5 hrs from its confluence with río Orinoco (3°5’N, 65°55’W), 16 Mar 1987, H. Lopez and O. Castillo , V87-24 ; CAS 222741 (1*, 153.7 mm) , FMNH 117085 [ex. ANSP 161532 ] (1*, 149.5 mm) , INPA 25071 (1*, 138.2 mm), same data as holotype ; MBUCV-V 25604 (2*, 158.8, 160 mm), río Casiquiare, ca. 1.5 hrs des de boca en río Orinoco , 16 Mar 1987 ; MCNG 54111 [ex. ANSP 161533 ] (1, 162.5 mm) ; MCP 38652 [ex. ANSP 161533 ], (1*, 142.8 mm), same data asANSP 161533; MZUSP 88065 (1*, 139.6 mm), same data as holotype ; UNT 3782 [ex. ANSP 161533 ] (1*, 138.5 mm), same data as ANSP 161533; USNM 384343 (1*, 149.6 mm), same data as holotype .

Non-types. Brazil: Amazonas: ANSP 178535 (1), rio Negro ( Amazonas dr.), 7 miles upstream from Leprosario, 7 miles downstream from Santa Maria (3°2’12"S, 60°22’40"W), 18 Jul 1996 , MTP-96-008; ANSP 180919 (1), rio Negro ( Amazonas dr.), 10 km downstream from Carvoeiro (1°22’8"S, 61°54’22"W), 9 Dec 1993 , JGL-93-190; ANSP 180920 (2*, 97.7, 104.6 mm), rio Negro ( Amazonas dr.), 3.8 km downstream from S. Francisco (1°41’10"S, 61°27’3"W), 6 Dec 1993 , JPF-93-158; ANSP 180921 (2 + 1*, 116.8 mm), rio Negro ( Amazonas dr.), 37.8 km upstream from Carvoeiro (1°12’27"S, 62°15’3"W), 10 Dec 1993 , MG-93-037; ANSP 180922 (1), rio Negro (Amazonas dr.), 15.7 km downstream from Moura, below rio Branco (1°33’51"S, 61°33’W), 7 Dec 1993 , JNB-93-012. Leptodoras cf. catania (Amazon form): Brazil: Amazonas : ANSP 178544 (1*, 97.4 mm), rio Madeira (Amazonas dr.), 9 km upstream from Vila Urucarituba (3°35’28"S, 58°56’53"W), 6 Aug 1996 , CCF-96-078; ANSP 180923 (1), rio Amazonas ( Atlantic dr.), 4 miles downstream from Nova Oriente, upstream from mouth of Madeira (3°16’29"S, 58°56’33"W), 5 Aug 1996 , CCF- 96-072; ANSP 180924 (1), rio Amazonas (Atlantic dr.), upstream from Itacoatiara (3°16’36"S, 58°57’1"W), 5 Aug 1996 , AMZ-96- 134; ANSP 180925 (7 + 5*, 120.3-194 mm), rio Içá ( Amazonas dr.), 1.5 km downstream from Betania (3°5’35"S, 68°4’58"W), 19 Nov 1993 , OTO-93-075; ANSP 180926 (1*, 86.5 mm), rio Jutaí ( Solimões dr.), between Pto. Antunes and Foz do Jutaí (2°50’6"S, 66°55’39"W), 13 Nov 1993 , JPS-93-049; ANSP 180927 (2, 40.23, 59.6 mm), rio Purus ( Solimões dr.), 8 km downstream from Beruri (3°50’35"S, 61°23’45"W), 26 Jul 1996 , FL-96-002; ANSP 180928 (1, 55.1 mm), rio Purus ( Solimões dr.), near confluence with Solimões (3°41’22"S, 61°28’19"W), 30 Jul 1996 , AMZ-96-110. Para: ANSP 180929 (2), rio Amazonas ( Atlantic dr.), 10.2 km upstream from Monte Alegre, below Tapajos (2°4’45"S, 53°59’49"W), 5 Nov 1994 , AMZ-94-023. Roraima: ANSP 178532 (1*, 131.9 mm), rio Branco ( Negro dr.), between Atauba and Caruna, 9.3 km above confluence with Negro (1°19’34"S, 61°52’13"W), 8 Dec 1993 , JGL-93-171. Tocantins: UNT 150 (2), rio Tocantins, Pedro Afonso , near confluence with rio Sono (8°59’S, 48°10’W), 18 Feb 1996 . Ecuador: Napo: FMNH 97138 (1*, 87.9 mm), río Tiputini , (Napo- Amazonas dr.), at confluence with río Napo (0°48’54"S, 75°32’30"W), 28 Oct 1981 , DJS81-64. Peru: Loreto: ANSP 178248 (1*, 77.4 mm), río Amazonas (Atlantic dr.), main channel along west bank, ca. 30-45 min. upstream from inlet to Iquitos, mouth of río Itaya , south of Iquitos , 3 Aug 2001 , Peru 2001-05. Leptodoras cf. catania (Nanay form): Peru : Loreto: ANSP 73173 (1 + 1*, 130.5 mm), río Ucayali (Amazonas dr.), Contamana, Jul-Aug 1937; ANSP 178438 (3 + 2*, 141.8, 164.2 mm), río Nanay (Amazonas dr.), Pampa Chica, village 4.54 km west of Iquitos (large beach along north bank), 2 Aug 2001 , Peru 2001-02; ANSP 179863 (5), río Nanay ( Amazonas dr.), large beach (left bank) at village of Pampa Chica, 4.54 km west of Iquitos (3°45’9"S, 73°17"W), 18 Aug 2003 , PERU 2003-05; INHS 39814 (48 + 5*, 93.1-117.3 mm), río Nanay (Amazonas dr.), playa about 1 hr by canoe upstream from Santa Clara (3°46.63’S, 73°22.21’W), 19 Aug 1996 ; INHS 44194 (3), río Nanay (Amazonas dr.), upstream from Santa Clara , 13.9 km west of Iquitos , bearing 78° (3°46’54.6"S, 73°21’49.6"W), 29-30 Jul 1997 , Peru 97-8; INHS 53722 (11 + 2*, 89.7, 94.7 mm), río Nanay ( Amazonas dr.), Pampa Chica, 4.54 km west of Iquitos , bearing 269° (3°45’08.8"S, 73°17’00.1"W), 7 Aug 1999 , Peru 99-12; SIUC 28582 (4) , same data as INHS 39814; SIUC 29472 (3), río Nanay (Amazonas dr.), playa, just upstream from Santa Clara , 13.9 km (bearing 78°) from Iquitos, 29-30 Jul 1997 ; SIUC 29859 (5 + 4*, 122-181 mm), río Nanay (Amazonas dr.), Pampa Chica, 4.54 km west of Iquitos , bearing 269°, 11 Aug 1997 .

Diagnosis. Distinguished among Leptodoras by a specific feature of upper labial extension ( Figs. 4g , 5 g-i): distal portion distinctly elongated, forming acute tip (sometimes appears as an enlarged terminal fimbriae). In species with similarly shaped upper labial extensions (e.g., L. acipenserinus , nelsoni ,

rogersae ) the distal margin is rounded or with comparatively small terminal fimbriae.

Description. Morphometrics summarized in Table 2. Overall shape similar in L. cataniai sensu stricto and two forms L. cf. cataniai Amazon ( Figs. 18d , 23 ) and Nanay ( Figs. 18c , 19b , 24 ), close to L. rogersae ; body very elongate and dorsoventrally depressed, ventrally flattened from snout to vent; head depressed with acute snout; caudal peduncle long, shallow, depressed. Relative snout length longest in Nanay form (42.4- 46.6% of predorsal distance), shortest in L. cataniai sensu stricto (35.4-40.2%), intermediate inAmazon form (37.6-41.3%). Eye rather large with adipose eyelid moderately (Nanay form) to well-developed ( L. cataniai sensu stricto andAmazon form).

Mouth subterminal, jaws edentulous in adults, small juveniles less than 80 mm SL with few thin acicular teeth near distal medial symphysis of dentaries. Maxillary barbel long, usually reaching ventromedial extent of gill opening. Secondary maxillary barbels 9-12 (modally 10), flattened, overlapping proximally, separated distally; proximal secondary maxillary barbels with fimbriate anterior margin and smooth posterior margin; distal ones smooth. Oral hood very well developed, expanded posteriorly (distance from jaw margin to tip of upper labial extension 33-47.8% of predorsal distance). Upper labial extension very elongate, proximal half straight and narrow, distal half curved medially and distinctly expanded with wide lateral flap bearing fimbriae, distal tip distinctly acute, often appearing as enlarged terminal fimbriae; surfaces smooth. Lower labial extension narrow, finishing before upper labial extension, tip often slightly expanded with terminal fimbriae. Interlabial membrane narrow (labial extensions convergent), comparatively thin with few small papillae. Dorsolabial membrane very well developed, laterally expanded and widely rounded posteriorly. Two pairs of jaw barbels with scattered elongate papillae; cojoined by basal membrane; outer pair longer than inner pair and shorter than maxillary barbel, cojoined with lower labial extension via narrow membrane. Branchiostegal membrane with well-expanded fleshy margin greatly overlapping ventral gill opening; fleshy inner flap along cleithrum complete, reaching cleithral notch. First gill arch ( Fig. 6b ) with gill rakers absent or inconspicuous, entirely contained within basal membrane (tips not apparent); accessory lamellae well developed, extending from basal membrane across lateral and medial faces of arches and filaments; lamellae numerous, on every second gill filament and broken into column of lappets with first lappet on medial face enlarged, deflected dorsomedially.

Sum of midlateral plates highly variable (Table 3); lowest in Nanay form (79-86, modally 82), highest in Amazon form (83-92, modally 88), intermediate in L. cataniai sensu stricto (82-87, modally 84). Anterior midlateral plates deep, usually covering at least half of corresponding body depth; posterior margins of dorsal and ventral wings rounded with many small serrae. Tympanum usually with 3 distinct ossifications (simple spines) along postotic laterosensory canal; small fixed spine usually conspicuous along posterior margin of neurocranium where postotic laterosensory canal exits supracleithrum. Postcleithral process very short and deep, distal portion expanded (especially dorsally) and dorsal and distals margin usually indistinct, covered with skin. Middorsal groove on nuchal shield well-defined. Subrectangular nuchal foramina present, replacing suture between epioccipital and anterior nuchal plate. Skin relatively smooth.

Dorsal-fin rays I,6; pectoral-fin rays I,9-11 (modally 10); pelvic-fin rays i,6; total anal-fin rays 14-17 (first 4 or 5 unbranched); caudal-fin rays i,8/9,i; dorsal procurrent caudalfin rays 14-19, ventral procurrent caudal-fin rays 12-16. Dorsal-fin spine rather long, very thin, relatively straight in juveniles, becoming sinuous in large adults; anterior denticulations antrorse, rather small and crowded basally, absent from distal third; posterior denticulations weakly retrorse to straight, weak, rather inconspicuous. Pectoral-fin spine as in L. acipenserinus . Pelvic fin comparatively long and pointed. Anal fin triangular with falcate distal margin; tip of longest branched ray more or less even with vertical through base of last branched ray when fin extended. Caudal fin deeply forked with elongate and pointed lobes.

Coloration in alcohol. Overall pattern similar to that of L. acipenserinus , nelsoni and rogersae . Head and body weakly to moderately countershaded, upper sides tan or gray-brown, lower sides and undersurfaces white. Wide dusky middorsal stripe evident in Amazon and Nanay forms, rather faint in L. cataniai sensu stricto. Melanophores weakly concentrated in skin between and above dorsal wings of midlateral plates, forming faint dusky stripe.

Fin coloration exhibits variation presumably influenced by environmental conditions, specifically black vs. whitewater habitats. In most specimens from the río Amazonas (whitewater) the fins are rather darkly pigmented. Dorsal fin with faint stippling on rays and along insertion; darker stippling along anterior margin of dorsal spine and on skin surrounding dorsal-locking spine. Pectoral fin dark with melanophores most concentrated on anterior rays, membranes, and skin between posterior denticulations of pectoral spine; posterior membranes with fainter stippling, posterior rays usually depigmented. Pelvic fin with dark stippling on anterior membranes forming streaks distally; rays and posterior membranes depigmented. Anal fin cream, hyaline. Divergent pair of dusky stripes on caudal fin very distinct as in L. nelsoni and L. rogersae . In specimens from the rio Negro ( L. cataniai sensu stricto) and río Nanay (both blackwaters) the dorsal, pectoral and pelvic fins are almost completely depigmented, cream, hyaline. The dusky divergent stripes on the caudal fin are retained but faint.

Coloration in life. Leptodoras cf. cataniai from the río Nanay, Peru, appear white with a pinkish tint ( Fig. 19b ).

Distribution and habitat. Leptodoras cataniai sensu stricto is known from the rio Negro/Casiquiare Canal in Brazil and Venezuela ( Fig. 25 ). Leptodoras cf. cataniai is known from in or near the main channel of the río Amazonas (Amazonas form) and large tributaries of the upper Amazonas such as the Nanay and Ucayali (Nanay form). In addition Santos et al. (1984:52) figured (as Leptodoras acipenserinus ) a specimen from the lower Tocantins that is referable to L. cf. cataniai . In the lower río Nanay L. cf. cataniai is syntopic with L. acipenserinus and large schools of juveniles and adults of both species move into shallow, swift waters along large sandy beaches at night. The río Amazonas form has been collected in bottom trawls at depths ranging from 1.7 to 35 m (J.G. Lundberg, unpubl. data) and occurs syntopically with L. juruensis and L. myersi near Iquitos, Peru.

Etymology. Named in honor of David Catania, for his dedicated service to the ichthyological community since 1985 as Collection Manager of Fishes, California Academy of Sciences.

Figures

Fig. 4. Variation in oral-hood morphology in Anduzedoras and Leptodoras. a. A. oxyrhynchus,ANSP 160628 (SL 124.6 mm). b. L.praelongus,ANSP162464 (SL 124.9 mm).c.L.copei,ANSP 162461 (SL95.9 mm).d. L.hasemani,ANSP 175889(SL86.7 mm). e. L. linnelli,ANSP 175883 (SL 94 mm). f. L. nelsoni, MCNG 13167 (SL 93 mm). g. L. cataniai,ANSP 161533 (SL 162.5 mm).h. L. juruensis, INHS 39465 (SL 117.4 mm). i. L. myersi,ANSP 112319 (SL 72.6 mm).

Fig. 5. Ventral views of heads in Leptodoras. a. L. linnelli, MBUCV-V 16602 (SL 157 mm). b. L. nelsoni, MBUCV-V 14769 (SL 135.8 mm). c. L. rogersae, USNM 226307 (SL 180 mm). d. L. acipenserinus, FMNH 92385 (SL 155 mm). e. L. acipenserinus, FMNH97140 (SL 113.3 mm).f.L.acipenserinus,ANSP 178467 (SL 107.9 mm). g. L.cataniai,ANSP 161532 (SL 142.6 mm).h. L. cf. cataniaiAmazon form,ANSP 180925 (SL 194 mm). i. L. cf.cataniai Nanay form,ANSP 178438 (SL 164.2 mm).

Fig. 6. Lateral (left) and medial (right) views of 1st gill arch.a. Leptodoras copei,ANSP162466 (SL 141.5 mm).b.Leptodoras cataniai,ANSP 161532 (SL 148 mm).

Fig. 18. Juvenile and subadult Leptodoras (Amazon basin). a. L. acipenserinus, FMNH 97140 (SL 113.3 mm), río Coca (Napo dr.), Napo, Ecuador. b. L. acipenserinus,ANSP 178467 (SL 107.9 mm), río Nanay, Loreto, Peru. c. L. cf. cataniai Nanay form, INHS 39814 (SL 109.2 mm), río Nanay, Loreto, Peru. d. L. cf. cataniai Amazon form, ANSP 180925 (SL 120.3 mm), rio Iça, Amazonas, Brazil. e. L. cataniai,ANSP 180912 (SL 104.6 mm), rio Negro,Amazonas, Brazil.

Fig. 22. Leptodoras cataniai, holotype,ANSP 180918 (SL 171 mm), río Casiquiare (Negro dr.) from mouth of rio Pamoni to 4 km below mouth,Amazonas, Venezuela.

Fig. 23. Leptodoras cf. cataniai Amazon form, ANSP 180925 (SL 194 mm), rio Iça (Amazonas dr.), 1.5 km downstream from Betania,Amazonas, Brazil.

Fig. 19. Live coloration in Leptodoras. a. L. acipenserinus,ANSP 178467 (SL 108 mm), río Nanay (Amazonas dr.), near Iquitos, Loreto, Peru. b. L. cf. cataniai Nanay form, ANSP 179863 (SL 144 mm), ibid. c. L. myersi, ANSP 181045 (SL 78.6 mm), río Amazonas, near Iquitos, Loreto, Peru.

Fig. 24. Leptodoras cf.cataniai Nanay form,ANSP 178438 (SL 164.2 mm), río Nanay (Amazonas dr.), near Iquitos, Loreto, Peru.

Fig. 25. Distributions of Leptodoras cataniai (solid light blue circles, star denotes type locality), L. cf. cataniai Amazon form (solid dark blue circles) and L. cf. cataniai Nanay form (open circles).