Laemolyta garmani ( Borodin, 1931 )

Mautari, Kelly Cristina & Menezes, Naércio Aquino, 2006, Revision of the South American freshwater fish genus Laemolyta Cope, 1872 (Ostariophysi: Characiformes: Anostomidae), Neotropical Ichthyology 4 (1), pp. 27-44 : 34-36

Laemolyta garmani ( Borodin, 1931)

Fig. 12

Anostomus (Schizodontopsis) garmani Borodin, 1931: 47–48 [original description, type locality: Jutahy (Jutaí), Içá, Lake Hyavary ( Lago Javarí )].

Laemolyta garmani: Myers, 1950: 197 [diagnosis, type locality]; Fowler, 1950: 208 [synonymy, distribution]; Géry, 1974: 152–153, 159 [description and identification key]; Ortega & Vari 1986: 12 [catalogue]; Garavello & Britski, 2003: 73 [catalog].

Laemolyta taeniata garmani: Géry, 1964: 466 [identification key].

Laemolyta garmani macra Géry, 1974: 153–154 , fig. (2), p. 154 [original description, type locality: rio Nacuray, identification key]; Weber, 1998: 8 [catalog of fishes]; Eschmeyer, 1998: 963 [catalog]; Garavello & Britski, 2003: 73 [catalog].

Anostomus (Laemolyta) garmani: Géry, 1977: 179 [identification key, distribution].

Anostomus garmani: Vari & Howe, 1991:5 . [Paratype, catalog]; Eschmeyer, 1998: 631 [catalog].

Material examined: 50 specimens (39.8–214.6 mm SL). Brazil. Amazonas: Silva, lago Saracá ( Lake Saracá at Silves ), 02°53’S, 58°21’W, December 1865, Thayer S. V. R, MCZ 19370, holotype , 160.6 mm SL. Rio Hyutahy, rio Jutahy [ rio Jutaí , tributary of rio Solimões ), 02°43’S, 66°57’W, September 1865, W. James, S. V. R . Thayer & “Talismã”, MCZ 19346, 7 out of 14 paratypes, 78.4– 95.0 mm SL. Rio Içá, rio Putomajo [rio Içá, tributary of rio Solimões, near Brazilian-Colombian border], 03°07’S, 67°58’W, MCZ 19366, 3 out of 5 paratypes, 63.6–72.9 mm SL. Rio Hyavary, rio Javary [rio Javarí, tributary of rio Solimões, at Peruvian Brazilian border], 04°21’S, 70°02’W, 19 October 1865, Bourget, D, MCZ 32099, 1 out of 2 paratypes, 116.7 mm SL. Silva, lago Saracá [Lago Saracá at Silves], (02°53’S, 58°21’W), December 1865, Thayer, S. V. R MCZ 94491 , 1 paratype, 163.7 mm SL. Lago do Castanho , INPA 10823 , 1, 126.2 mm SL. Janauacá, rio Solimões , INPA 15210 , 1 , 75.3 mm SL. Janauacá, rio Solimões , INPA 10876 , 1, 213 mm SL. Rio Tefé, Ressaca de Paula , Tefé, MZUSP 32402 , 14 , 159.9 – 214.6 mm SL. Igarapé Baré, lago Amaná, mouth of rio Japurá , MZUSP 36070 , 1, 151.8 mm SL. Igarapé Urumutum, mouth of rio Japurá , MZUSP 36072 , 1, 178.1 mm SL. Rio Tefé , lago Tefé, MZUSP 61643 , 1, 195 mm SL. Rio Tefé , lago Mucura, MZUSP 61814 , 1 , 78.6 mm SL. Lago Manacapuru, rio Solimões , MZUSP 63614 , 1, 188.3 mm SL. Barra do rio Negro , NMW 56988 : 2, 1, 164.7 mm SL. Pará: lago Maria Preta, rio Capim , MZUSP 63828 , 1 , 39.8 mm SL. Mato Grosso: rio Aripuanã, ilha do Castanhal , INPA 24727 , 1, 168.8 mm SL. Rondônia: Forte Príncipe da Beira, rio Madeira , MZUSP 21381 , 1 , 50.4 mm SL. Goiás: rio Araguaia , Xambioá, INPA 1601 , 1, 142.3 mm SL. Ecuador. Napo: río Yasuni , laguna Jatuncocha FMNH 102132 , 1 , 77.9 mm SL. Peru. Concordia: río Marañon, tributary of río Nacuary (open water), MHNG 2197.38 , 1 , 71.1 mm SL, 59 (type material of Laemolyta garmani macra ). Departamento Loreto, Quebrada de río Yanayacu W of Miraflores ( río Marañon ), ANSP 165049 , 1 , 67.9 mm SL. Departamento Loreto, Provincia Maynas, Iquitos , Moronacocha, MZUSP 26333 , 5 , 44.5–82 mm SL. Loreto, río Nanay , about 20 km above mouth, main channel, lateral channels and lateral ponds, USNM 383198 , 1 , 70.2 mm SL.

Diagnosis. Laemolyta garmani is the only species in the genus with 4 longitudinal scale rows above the lateral line. Its color pattern is very similar to that of L. taeniata and L. orinocensis , but the dark longitudinal midlateral stripe and the narrow longitudinal light stripes above the lateral line are less conspicuous in L. garmani whereas L. orinocensis has more lateral line scales (40–44 vs. 47–52).

Description. Morphometric and meristic data are presented in Table 3. Body moderately large (SL = 39.8-214.6 mm). Dorsal profile of body straight, posterodorsally-aligned from tip of snout to end of supraoccipital spine, straight and rising from this point to dorsal-fin origin, straight and posteroventrally-aligned from that point to caudal peduncle. Ventral profile of body approximately straight and posteroventrally-aligned from tip of lower jaw to near isthmus, slightly convex from that point to anal-fin origin. Dorsal limb gill rakers on first gill arch 9-11, 12-14 on ventral limb.

Scales large, 40-44 (42*, usually 43, Table 2) perforated on all of lateral line. Longitudinal scale rows from lateral line to dorsal-fin origin 4; scales rows from lateral line to anal-fin origin 4. Predorsal scales 10-13 (10*, usually 11), scales regularly arranged in most specimens. Scales rows around caudal peduncle 15-16 (15*, usually 16).

Dorsal-fin rays i or ii,10-12 (10*, usually 11); distal margin of fin slightly rounded. Anal fin short and slightly falcate, with i-ii,8-9 (8*, usually 8) rays. Pectoral fin rays i,10-14 (12*, usually 14). Pelvic fin rays i,8; distal margin of fin truncate. Vertebrae 40 (N=3).

Color in alcohol. Upper part of body dark with dark coloration extending ventrally to about 1.5 longitudinal scale rows above lateral line. Conspicuous dark, midlateral, longitudinal stripe covering 1 to 1.5 longitudinal scale rows and extending from tip of snout to rear of caudal peduncle; stripe sometimes wider in opercular region and narrower in snout region and near to caudal peduncle. Scales above lateral line with central posterior region lighter and forming narrow light stripes or linear pattern of light dots along body.

Dorsal, pectoral, pelvic and caudal fins hyaline. Anal and adipose fins with scattered dark chromatophores.

Distribution. Amazon basin ( Fig. 13 ).

Remarks. Borodin (1931) described Laemolyta garmani and considered it to be very similar to L. taeniata , but distinguished his species by having larger and fewer scales and by the presence of a darker longitudinal stripe, fins, and scales. He also mentioned that the longitudinal dark stripe extends onto the middle caudal-fin rays and is clearly visible in preserved specimens even after 64 years. These characteristics and the presence of dark chromatophores on the fins and scales although less evident, are also present in L. taeniata , and, thus, are not useful to distinguish the two species. The two nominal species, however, can be separated primarily on the basis of scale size and consequently scale counts.

Laemolyta garmani was originally considered by Géry (1964) to be a subspecies of L. taeniata but later that author (1974) raised it to the species level and at the same time described a new subspecies, Laemolyta garmani macra based on a small sample of young specimens that had a shallower body. The holotype of this subspecies was not examined but M. Toledo-Piza (DZ-IBUSP) made counts and measurements on the specimen and a photo ( Fig. 14 ) was provided by C. Weber (MNHG).

Figure 15 demonstrates that the body depth of the holotype of Laemolyta garmani macra does not differ significantly when compared to all the examined specimens of L. garmani . Although body depth varies to a certain extent among the specimens, there is no statistical difference to justify recognition of a subspecies.

In his original description of Laemolyta taeniata, Kner (1859) mentioned that two specimens from Barra do rio Negro had thinner bodies, and some other divergent unspecified characters relative to the other examined specimens. One of these specimens, considered to be the syntype of L. taeniata (NMW 56988:2) was examined and proved to be identical to all the other specimens of L. garmani studied. This species was collected in sympatry with Laemolyta proxima and L. taeniata in Peru.

Figures

Fig. 12. Laemolyta garmani, holotype, MCZ 19370, 160.6 mm SL; Brazil, Amazonas, Silva, lago Saracá. Caudal fin entirely damaged and lacking in the holotype.

Fig. 13. Geographic distribution of Laemolyta proxima (black dots; open circle = type-locality), Laemolyta garmani (black squares; open squares = type-locality), and Laemolyta orinocensis (black triangles; open triangle = type-locality). Some symbols might correspond to more than one locality.

Fig. 14. Laemolyta garmani named “Laemolyta garmani macra”, MHNG 2197.38, 71.1 mm SL; Peru, río Marañon, Concordia, tributary of río Nucuray. Caudal fin damaged.

Fig. 15. Scatter plot of body depth on standard length for specimens and holotypes Laemolyta garmani.