Description of two new species of Physopyxis and redescription of P. lyra (Siluriformes: Doradidae) Sousa, Leandro M. Rapp Py-Daniel, Lúcia H. Neotropical Ichthyology 2005 2005-12-31 3 4 625 636 4HJFJ Sousa & Rapp Py-Daniel, 2005 Sousa & Rapp Py-Daniel 2005 [973,1187,193,217] Actinopterygii Doradidae Physopyxis Animalia Siluriformes 7 632 Chordata species cristata sp. nov.   Fig. 7     Holotype. INPA 24325( 22.73 mmSL), mouth of igarapé Zamula, rio Negro, Amazonas State, Brazil( 00°51’48”S, 62°46’44”W), N. L. Chao et al.,  20 Oct 2002.    Paratypes(N = 23). Brazil: Amazonas: ANSP 180960(2, 10.7- 11.04 mmSL), same data as holotype.  INPA 20193(2, 13.38- 14.42 mmSL), rio Caurés, rio Negrobasin.  INPA 20194(1, 12.64 mmSL), rio Caurés, rio Negrobasin.  INPA 21915(1, 10.64 mmSL), same data as holotype.  INPA 21916(1, 11.18 mmSL), igarapé Zamula, rio Negrobasin.  INPA 25063(1, 10.98 mmSL), rio Cuiuni, rio Negrobasin.  MZUSP 76209(2, not measured), beach of paraná do Jacaré, rio Negrobasin.  MZUSP 76210(2, not measured), Urumaribeach, two hours upstream Barcelos, rio Negro( 00°58’S, 62°57’W).  MZUSP 76211(1, not measured), Urumaribeach, two hours upstream Barcelos, rio Negro( 00°58’S, 62°57’W).  Roraima: INPA 25061(1, 10.93 mmSL), igarapé Corumbaú, rio Branco, rio Negro Basin.  INPA 25062(7 + 2 c&s, not measured), same data as INPA 25061.   Diagnosis.  Physopyxis cristatacan be easily distinguished from its congeners by possessing an incomplete lateral line that ranges between five and twelve lateral plates; lateral plates weakly ossified, externally visible only by posteriorly-oriented spine; tips of neural spines exposed, perforating skin middorsally along posterior portion of body, forming a crest between dorsal and caudal fins.   Description.Morphometric data summarized in Table 3. Largest specimen examined measures 22.73 mmSL. Body slightly slender, moderately deep with greatest body depth at origin of dorsal fin (body depth 27-30% of SL). Top of head and nuchal plates roof shaped, with bony ornamentation arranged in shallow grooves concentrated along nuchal shield crest and borders. Anterior nostril tubular and placed near border of snout. Posterior nostril nearer to orbit than to snout. Snout short, its length twice orbital diameter. Lacrimal bone well developed, dorsal and ventral margins serrated with conspicuous spines. Mouth terminal. Barbels simple, long, slightly compressed, with papillae along inferior surfaces. Maxillary barbel reaching to or surpassing tip of postcleithral process. Outer mental barbel reaching point of insertion of pectoral spine. Inner mental barbel slightly shorter than outer mental barbel. Scapular girdle as in  Physopyxis lyra. Cleithrum laterally expanded and visible from above, sculptured with shallow grooves up to postcleithral process. Postcleithral process relatively short, its tip reaching to or slightly surpassing vertical through dorsal-spine origin. Coracoid process very long, slender (larger than postcleithral process), with well defined straight longitudinal grooves and ridges along its entire length. Tip of coracoid process pointed, not expanded. Dorsal and pectoral spines strongly ossified, serrated and grooved as in  P. lyra. Lateral line incomplete and asymmetric, ranging from five to 12 lateral plates. Lateral plates weakly developed and embedded beneath skin, with only retrorse spines visible from outside. Tips of neural spines of vertebrae visible externally, emerging middorsally in posterior portion of body, forming crest between dorsal and caudal fins. Some specimens with tips of vertebral hemal spines visible externally, emerging midventrally on caudal peduncle.   Table 3.Descriptive morphometrics and counts of  Physopyxis cristata(N = 10). SD = Standard deviation. Hol = Holotype.     Hol  Range  Mean (SD)  Standard length (mm) 22.73 10.64–22.73  Total length (mm) 30.17 13.51–30.17   Percent of Standard length  Pre-dorsal length 40.65 39.40–41.11 40.04 (0.63)  Dorsal fin base 12.76 10.76–13.66 12.6 (0.99)  Body depth 28.68 27.17–30.14 29.03 (1.03)  Dorsal-adipose fin length 26 22.37–26.0 23.98 (1.22)  Adipose-caudal fin length 9.85 9.85–14.38 11.54 (1.52)  Pre-pectoral length 29.3 26.27–29.70 28.52 (1.08)  Pre-pelvic length 50.68 45.65–52.77 49.93 (2.41)  Pre-anal length 63.22 60.84–65.35 62.97 (1.51)  Anal fin base 22.88 22.72–25.04 23.48 (0.77)  Caudal peduncle length 7.83 4.92–8.46 7.03 (1.08)  Caudal peduncle depth 10.07 9.42–10.62 10.06 (0.37)  Lateral plate depth 4.14 2.35–4.14 3.15 (0.68)  Superior lateral plate portion depth - - -  Inferior lateral plate portion depth - - -  Body depth at 4th plate - - -  Dorsal spine length 29.3 26.63–35.51 31.22 (3.39)  Pectoral spine length 40.61 34.57–41.48 38.33 (2.65)  Head length 28.2 26.64–29.27 28.11 (0.8)  Maxillary barbel length 42.89 29.07–42.89 36.04 (5.79)  Scapular girdle width 38.36 38.36–42.11 39.6 (1.29)  Postcleithral process length 8.8 5.93–10.19 8.35 (1.57)  Coracoid process length 21.21 19.66–22.84 20.97 (1.04)  Pectoral girdle mesial suture 18.52 17.71–20.02 18.71 (0.76)  Dist between coracoid process tips 22.44 16.49–22.44 20.03 (1.78)  Coracoid width 28.16 24.37–28.62 26.81 (1.54)   Percent of Head length  Head depth 88.3 85.10–96.34 91.11 (3.75)  Orbital diameter 13.42 13.42–25.16 20.89 (3.18)  Interorbital width 48.05 48.05–56.95 54.01 (3.18)  Mouth inner width 39.01 38.95–47.45 42.57 (2.99)  Snout length 35.41 32.12–38.38 34.48 (2.17)   Counts  Mode  Dorsal fin rays I+5 I + 4–5 I+5  Pectoral fin rays I+4 I + 3–4 I+4  Pelvic fin rays 7 7 7  Anal fin rays 15 13–17 15  Caudal fin rays 11 10–12 12  Dorsal spine serrae 5 4–7 5  Lateral plates 10 5–12 10 Dorsal-fin rays I,4 or I,5. Dorsal-fin origin situated at anterior third of body. Pectoral-fin rays I,4. Pectoral fin located at vertical through branchial opening. Pelvic-fin rays 7. Pelvic fin inserted at vertical through coracoid process tip, approximately at middle of body. Tip of pelvic-fin rays reaching to anal-fin origin.Anal fin with 15 rays.Adipose fin small, membranous. Caudal fin truncate to slightly emarginate, with 8,4 rays.  Color in alcohol.  Physopyxis cristatahas same color pattern as described for  P. lyra.   Distribution.This species has been recorded only from middle portion of the rio Negro basin (Amazonas drainage), Amazonas State, Brazil.   Etymology.The name  cristata, from Latin cristatus, meaning crested, in allusion to externally visible series of emergent neural spines.   Habitat.Some specimens included in typeseries were found in accumulated leaf litter, suggesting habitat similar to that observed in  P. lyra. Dwarf cichlids of the genus  Apistogrammaand juvenile specimens of  Amblydoraswere collected with specimens of  P. cristata. 5223356342 2002-10-20 INPA N. L. Chao Brazil Amazonas State -0.86333334 Zamula 21 -62.77889 rio Negro 7 632 INPA 24325 1 holotype 5223356373 2002-10-20 ANSP Amazonas Brazil Amazonas State -0.86333334 Zamula 21 -62.77889 rio Negro 7 632 ANSP 180960 1 paratype 5223356333 INPA Brazil rio Negro rio Caures 7 632 INPA 20193 1 paratype 5223356390 INPA Brazil rio Negro rio Caures 7 632 INPA 20194 1 paratype 5223356380 2002-10-20 INPA N. L. Chao Brazil Amazonas State -0.86333334 Zamula 21 -62.77889 rio Negro 7 632 INPA 21915 1 paratype 5223356343 INPA Brazil rio Negro Zamula 7 632 INPA 21916 1 paratype 5223356375 INPA Brazil rio Negro rio Cuiuni 7 632 INPA 25063 1 paratype 5223356325 MZUSP Brazil rio Negro Jacare 7 632 MZUSP 76209 1 paratype 5223356360 MZUSP Urumari & Barcelos Brazil -0.96666664 rio Negro 1308 -62.95 7 632 MZUSP 76210 1 paratype 5223356394 MZUSP Urumari & Barcelos Brazil -0.96666664 rio Negro 1308 -62.95 7 632 MZUSP 76211 1 paratype 5223356313 INPA Brazil Corumbau rio Negro Basin rio Branco 7 632 INPA 25061 1 Roraima paratype 5223356378 INPA Brazil Corumbau rio Negro Basin rio Branco 7 632 INPA 25062 1 Roraima paratype