Brachyhypopomus occidentalis ( Regan, 1914 )

Crampton, William G. R., Santana, Carlos D. de, Waddell, Joseph C. & Lovejoy, Nathan R., 2016, A taxonomic revision of the Neotropical electric fish genus Brachyhypopomus (Ostariophysi: Gymnotiformes: Hypopomidae), with descriptions of 15 new species, Neotropical Ichthyology (e 150146) 14 (4), pp. 639-790 : 741-747

Brachyhypopomus occidentalis ( Regan, 1914)

( Fig. 35 ; Tables 2-5, 16)

Rhamphichthys (Brachyrhamphichthys) brevirostris . - Steindachner, 1880: 89 ( Colombia, Cauca dr., catalog of fishes).

Brachyrhamphichthys brevirostris . - Eigenmann & Eigenmann, 1891: 62 ( Colombia, Cauca dr., catalog of South American fishes).

Hypopomus brevirostris . -Eigenmann & Ward, 1905: 170, 186. pl. 10, fig. 13, black and white photograph without locality data, photograph is not of B. brevirostris ; it resembles B. occidentalis ( Colombia, Cauca dr., listing of gymnotiform species). - Eigenmann, 1910: 449 (Cauca dr., catalog of fishes). -Eigenmann & Fisher, 1914: 236 ( Colombia - Soplaviento [Magdalena dr.], Managru, Truando, Raspadura, Quibdó [Atrato dr.]; Calima [San Juan dr.], Gymnotiformes of trans-Andean Colombia and Ecuador). - Meek & Hildebrand, 1916: 310 ( Panama, río Chagres basin, río Bayano basin, Atlantic and Pacific drainages of Panama and Colombia, catalog of fishes). - Eigenmann, 1922: 174 (Atlantic and Pacific drainages of Panama, Atrato, San Juan and Magdalena drs., catalog of fishes in NW South America). -Eigenmann & Allen, 1942: 314 ( Panama, Chagres, listing of gymnotiforms). - Fowler, 1945: 179 ( Panama, catalog of fishes).

Hypopomus occidentalis Regan, 1914: 32 (original description, type locality – Colombia, Chocó, río Condoto, río San Juan dr.). - Eigenmann, 1922: 175 ( Colombia, río Condoto, catalog of fishes in NW South America). - Bussing, 1987: 99, fig. 37, black and white photograph ( Costa Rica, catalog of fishes). - Schultz, 1944: 40 (diagnosis against B. beebei ). - Schultz, 1949: 66, key to hypopomids; fig. 9a., illustration of arrangement of cephalic pores ( Venezuela, listings from Motatán and Maracaibo drs.). -Hagedorn & Carr, 1985: 513, fig. 1, drawing of breeding male and female, with sexual dimorphism of caudal filament ( Panama, reproductive ecology - image reprinted in Hagedorn, 1986: 512, fig. 4; Hagedorn: 1988, 330, fig. 2; Kramer: 1990, 14, fig. 1.6). - Galvis et al., 1997: 102, color photograph of live individual ( Colombia, río Catatumbo dr., fish list for NW South America). - Bussing, 1998: 134, black and white photograph, note on diet ( Costa Rica, catalog of fishes).

Brachyhypopomus occidentalis . -Mago-Leccia, 1994: 48, 170, fig. 70, line drawing of head and anterior portion of body of specimen MBUCV-V 14112, río Guaco, Maracaibo dr., Venezuela (in listing of Brachyhypopomus ). - Sullivan, 1997: 133 (redescription). -Bermingham & Martin, 1998: 502, 505 ( Panama - Atlantic and Pacific drs.; Colombia - Atrato and Magdalena drs., molecular phylogeography). - Hopkins, 1999: 1218, fig. 1, black and white photographs of breeding male and female, reproduced from Hagedorn, 1988: 330, fig. 2 (electric organ morphology and impedance matching). -Albert & Crampton, 2003: 495 ( Colombia, Panama, catalog of hypopomids). - Crampton & Albert 2006: 672, fig. 23.8, position in phylogenetic tree; 681, notes on EODs (gymnotiform species and EOD diversity). -Crampton, 2011: 176, table 10.2, species list; 179, figs. 10.2-10.3, phylogeny, geographical and ecological distributions (gymnotiform biology). -Maldonado-Ocampo et al., 2012: 323, color photograph of live individual ( Colombia - Atrato, San Juan, Baudó, Calima, Anchicayá, Dagua, Mira drs., listing of fish in Chocó, Colombia). - Carvalho, 2013: 147, fig. 3D, outline of head; 181-185, figs. 41-43, position in phylogeny (phylogenetic systematics of Rhamphichthyoidea ). - Picq et al., 2014: 1520-1532 ( Panama and Colombia, phylogeography). - Elbassiouny et al., 2016: 402-403, fig. 1 (position in phylogeny of Ostariophysi, based on mitochondrial genomes). - Picq et al., 2016 (EOD evolution). - Tagliacollo et al., 2016: 28, fig. 5 (phylogeny of Gymnotiformes ). - Crampton et al., 2016: 1-66, table 1, 3-4, figs. 1-7, 13, 18-20 (phylogeny, biogeography and ecology of Brachyhypopomus ).

Diagnosis. Brachyhypopomus occidentalis is diagnosed from congeners by the following combination of characters: absence of series of diffuse horizontal dash-like dark markings along lateral line in posterior third of body, anterior to anal-fin terminus, vs. presence in B. alberti , B. arrayae , B. hamiltoni , and B. draco ; pale stripe along middorsal region of body absent, vs. prominent pale uninterrupted middorsal stripe from occipital region to base of caudal filament in B. beebei , B. belindae , B. gauderio , B. pinnicaudatus , and B. verdii ; anal-fin rays 191-254, vs. 155-225 in B. batesi , B. flavipomus , B. menezesi , and B. sullivani ; pectoral-fin rays 15-20, vs. 10-13 in B. benjamini and B. cunia ; bilateral columns of electrocytes at anal-finterminus 4-5 (or 3 insomepopulationsinColombiaand Venezuela, see below), vs. 6 in B. bennetti ; accessory electric organ over opercular region absent, vs. present in B. bombilla and B. regani ; caudal filament short, 11.5-30.7% LEA, vs. 31.3-64.5% in B. bullocki , B. hendersoni , and B. janeiroensis ; diagonally oriented bars on flank diffuse and mostly break up ventral to lateral line, vs. vertical bars form distinct saddles which extend across lateral line in B. brevirostris ; continuous or discontinuous dark vertical or diagonally oriented stripes or saddles present on body surface dorsal to lateral line, vs. absent in B. jureiae , B. palenque , and B. provenzanoi ; dark suborbital stripe absent, vs. present in B. walteri . Brachyhypopomus occidentalis exhibits similar pigmentation and overlapping meristic counts and morphometric proportions with B. diazi . These two species can be distinguished by the more extensive network of depigmented and dark-margin epidermal canals in B. diazi (including in the anterior half of the body) than in B. occidentalis , and by the first branchiostegal ray is approximately as wide as the third branchiostegal ray in B. occidentalis , vs. the first branchiostegal ray is distinctly narrower than the third in B. diazi .

Description. Head and body shape, and pigmentation illustrated in Fig. 35 . Meristic and morphometric data for examined specimens presented in Tables 2-5 and 16. Body shallow to moderate in depth. Head short to moderate in length and shallow to moderate in depth. Dorsal profile of head straight to gently convex from occiput to snout, ventral profile of head slightly concave between operculum and snout, snout rounded. Eye small to moderate in size. Upper jaw slightly to moderately prognathous. Upper jaw with slight sigmoidal angle between premaxillary and maxillary portions in lateral view. No accessory electric organ over operculum. Gill filaments on first gill arch 35-54 (median 48, n = 10). Pectoral fin narrow to broad in width, pectoral-fin rays 15-20. Modes and ranges similar for specimens from Pacific coastal drainages of Colombia (16-18, mode 17), Maracaibo drainage (15-18, mode 17), eastern Atlantic drainages of Panama (16- 18, mode 17), and eastern pacific drainages of Panama (15- 18, mode 17), but slightly higher for specimens from western Atlantic drainages of Panama (río Cricamola) (18-21, mode 18). Precaudal vertebrae 17-20. Modes and ranges similar for specimens from Pacific coastal drainages of Colombia (19-21, mode 19), eastern Atlantic drainages of Panama (18-19, mode 19), western Atlantic drainages of Panama (18-20, mode 19), and eastern pacific drainages of Panama (18-20, mode 19), but slightly lower for specimens from the Maracaibo drainage (17-19, mode 18). 1-3 transitional vertebrae (mode 2 in all examined populations). Anal-fin origin slightly (<0.25 HL distance) anterior to, or posterior to, or near, tip of pectoral fin. Anal-fin rays 194-254. Ranges and medians for specimens are similar for specimens from the following three regions: eastern Atlantic drainages of Panama, 194- 234 (216); western Atlantic drainages of Panama, 199-228 (216); eastern Pacific drainages of Panama, 212-229 (216). Ranges and medians are slightly lower for specimens from the Maracaibo drainage, 201-213 (203), and slightly higher for specimens from the Pacific coast of Colombia 207-254 (222). Dorsal rami of recurrent branch of anterior lateral line nerve not visible. Middorsal region of body scaled. Rows of scales above lateral line 5-7 (mode 7). Lateral line continuous. Depigmented epidermal canals sparse, and mostly restricted to posterior half of body. In anterior half of body canals occur in low density in upper portions of flank, usually as single meandering lines in dorsal flank around midway between lateral line and dorsal midline, nearer to lateral line posteriorly. In second half of body canals occur as multiple parallel wavy lines in dorsal and (less commonly) in ventral flank, approximately parallel to lateral line. Density of epidermal canals somewhat higher in populations from the Maracaibo basin, but in all populations considerably less extensive and conspicuous than in B. diazi . Number of bilateral electrocyte columns: in populations from region of type locality (río Condoto): 4 columns at anal-fin terminus in immature specimens and 4-5 (mode 4) in mature females and males, and 4-5 (mode 4) columns at a midpoint from anal-fin terminus to tip of caudal filament in immature specimens, mature females and males. In some specimens extra electrocyte columns appear posterior to mid-point between anal-fin terminus and tip of caudal filament – especially in laterallycompressed paddle-like tip – bringing maximum number of columns to 5-6 (in both males and females). Specimens with regenerated caudal filaments often have more columns of electrocytes in regenerated portions. We noted population-level variation in number of bilateral columns of electrocytes in B. occidentalis . For example, number measured at anal-fin terminus was: río Atrato, Colombia (3-4, mode 3, n = 9); río Magdalena, Colombia (3, n = 9); río Sinú, Colombia (3, n = 1), río Motatan, lago Maracaibo, Venezuela (3-4, mode 3, n = 22); río Chagres, Panama (4-6, mode 5; increasing to 6-7 columns in laterally compressed caudal filament tip, n = 12), río Mandingá, Panama (3, n =5); río Cricamola, Panama (4, n = 12), río Sixaola, Costa Rica (4-5, mode 4, n = 9). More work is needed to fully characterize population-variation in gross anatomy of the electric organ of B. occidentalis , much of which may be explained by impedance matching to ambient conductivity. Caudal filament short to moderate in length.

Coloration. ( Fig. 35 ). Pigmentation highly variable within and between regions. Eigenmann (1922, 174-175), discussed variation in pigmentation among populations of B. occidentalis from the Magdalena, Atrato, and San Juan drainages of Colombia. Background pale tan to dark brown, usually considerably darker dorsally. Dorsal region without prominent depigmented pale stripe extending along midline from occipital region to base of caudal filament. Dorsal surface with speckling of lighter pigment on dark background, and sometimes with irregular dark patches which may extend into thin vertically oriented or diagonal incomplete bands that extend across flank; banding if present is usually more conspicuous in anterior third of body.Ventral flank over anal-fin pterygiophores with irregular dark patches forming a marbled pattern. Caudal filament darker than body. Head with evenly scattered dark chromatophores, darker dorsally. Eye without prominent suborbital patch, or stripe, of chromatophores/ subcutaneous pigmentation. Pectoral and anal-fin membranes hyaline. Pectoral-fin rays hyaline with light scattering of dark chromatophores. Color in live individuals similar to preserved specimens, often with olive green tinge, opercular region usually rosy due to underlying gills, body cavity of gravid females often yellow due to underlying ripe eggs ( Fig. 35d ).

Size. Moderate adult size, largest specimen examined 278 mm, 216 mm TL (n = 892). Largest male specimen examined 278 mm TL, 216 mm LEA (n = 18). Largest female specimen examined 162 mm TL, 144 mm LEA (n = 33).

Sexual dimorphism. We observed population variation in the degree to which caudal morphology differs between breeding males and females, which may be correlated to electrical conductivity. Conductivity varies considerably among drainages occupied by B. occidentalis , including low-conductivity systems (ca. 5-60 μScm-1) and high-conductivity systems (ca. 100-450 μScm-1). In low-conductivity systems (e.g. streams of the río Cricamola, río Atrato, conductivity 5-30 μScm-1, NRL, WGRC pers. obs.), breeding males appear to develop longer and marginally widened caudal filaments. In contrast, in very high conductivity systems (conductivity 300-450 μScm- 1 in some streams of the río San Juan, río Bayano listed in ‘Material examined’, and parts of Panama, NRL pers. obs.), breeding males develop very wide but not very elongated caudal filaments. These observations suggest population-level variation in caudal filament morphology associated with impedance matching sensu Hopkins (1999) and merit a more detailed quantitative study.

In addition to exhibiting enlarged caudal filaments, the number of bilateral columns of electrocytes at the anal-fin terminus increases slightly, from invariably 4 in immature specimens and females to 4-5 (mode 4) in breeding males. Breeding males also exhibit clearly enlarged electrocytes relative to immature specimens and females. Large breeding males commonly with paddle-like lateral compression at caudal filament tip ( Figs. 35 c-d). No known sexual dimorphism in pigmentation.

We noted population variation in the maximum size attained by males. Breeding males in museum collections from two drainages, the río San Juan and río Cricamola, were considerably larger than females (ca. 260-278 mm in fully mature males, vs. ca. 103-153 mm in fully mature females). In contrast, mature males were only marginally larger than females in other drainages, including the río Atrato, Atlantic and Pacific drainages of eastern Panama, and Maracaibo drainages. Based on the phylogeny of Picq et al. (2014), these observations suggest multiple independent origins of a prominent secondary sexual dimorphism of body size.

Geographic distribution. Colombia, Costa Rica, Panama, and Venezuela ( Fig. 36 ). Westernmost records from the río Sixaola drainage, an Atlantic drainage of Costa Rica. Known from multiple Atlantic and Pacific drainages throughout Panama, but note gaps in collecting records in Fig. 36 . Widespread through Pacific coast of Colombia, including the río Atrato (Atlantic drainage), río San Juan, río Baudó, río San Cipriano and rio Anchicayá (Pacific drainages). Isolated records from the río Sinú (Atlantic drainage) and lower and middle río Magdalena (Atlantic drainage). Widespread in lowland drainages around the entire perimeter of lago de Maracaibo.

Population variation: We found complete overlap in the range of meristic counts ( Tables 2-5) and morphometric proportions ( Table 16), and observed similar pigmentation among specimens from five geographical regions. Specimens from no single region exhibited consistently divergent meristic counts or morphometric proportions (see ‘Description’, and ‘Sexual dimorphism’). These observations, in combination with molecular data ( Crampton et al., 2016), support the hypothesis that all populations we have assigned to B. occidentalis are members of a single geographically widespread species, which is morphologically and genetically distinct from all congeners.

Mirroring the results of an earlier study by Birmingham & Martin (1998), Picq et al. (2014), presented a population level phylogeny of B. occidentalis in which populations from west Panamanian Atlantic drainages (Cricamola, Sixaola, Changuinola, Calovébora) form the sister taxon to populations from all other regions of Panama and northwestern Colombia (including Pacific and Atlantic drainages); both studies also concluded that populations from lago Maracaibo drainages constitute the sister taxon to all Panama-Colombia lineages. Picq et al. (2013; 2016) noted EOD divergences between populations in independent drainages consistent with non-adaptive drift, and observed an unusual divergence of the EOD waveforms of breeding males in the río Cricamola relative to other Panamanian populations. Although we did not note salient morphometric and meristic differences between specimens of B. occidentalis from the río Cricamola versus other populations of B. occidentalis , we did observe a more extreme form of sexual size dimorphism and larger maximum body sizes in río Cricamola specimens than in populations from other Panamanian drainages, the río Atrato, and lago Maracaibo (see ‘Sexual dimorphism’).

Ecological notes. Brachyhypopomus occidentalis is common in small, gently-flowing streams and shallow swamps and lagoons throughout its range ( Bussing, 1987; Crampton, 2011; Hagedorn, 1988). Water parameters, including pH, conductivity (see ‘Sexual dimorphism’), dissolved oxygen, and turbidity are highly variable in the systems inhabited by this species. The reproductive ecology and mating behavior of Panamanian B. occidentalis have been documented in detail by M. Hagedorn and co-authors ( Hagedorn, 1986; 1988; Hagedorn & Zelick, 1989; Kawasaki & Heiligenberg, 1989). Brachyhypopomus occidentalis breeds through the dry season, reaching maturity in its first year and exhibiting post-reproductive mortality indicative of an annual lifecycle. Individuals exhibit a high degree of site fidelity.

Stomach contents of B. occidentalis from the Atrato drainage of Colombia comprise aquatic insect larvae (especially Chironomidae ) and other small aquatic invertebrates (WGRC unpublished data). Bussing (1987; 1998) also reported a diet of aquatic invertebrates, especially Diptera , in populations from Costa Rica. Dunlap et al. (2016) infer predation of Panamanian B. occidentalis by the heptapterid catfish Rhamdia – based on correlations between caudal filament damage and the density of Rhamdia .

Co-occurring congeners: None.

Local names. Colombia: cuchillo, beringo culebra (Atrato), mayupita (Catatumbo) ( Galvis et al., 1997); Costa Rica: madre de barbudo ( Bussing, 1987); Panama: cuchillo.

Material examined. 773 specimens. Colombia. Antioquia (localities from Atlantic drainages). CAS 72231, 1, 65 mm, quebrada Cristalina at Cristalina, 28 km above Puerto Berrio, río Magdalena dr., ca. 06°16′N, 074°32′W. IAVH-P 7278, 4, mun. Turbo, caño Tumarado, last ‘cienaga’ [swamp], Puerto Plata Vereda, El Cuarenta, río Atrato dr., 07°42′34″N, 077°01′46″W. IAVH-P 7411, 1, caño Muerto, last “cienaga” [swamp], Vereda [village] El Cuarenta, río Atrato dr., 07°42′31″N, 077°01′56″W. Bolívar. FMNH 56788, 5, 88-142 mm, SU 63675, 5, 88-142 mm, Canal de Dique between Cartagena and Calamar, at Soplaviento, affl. río Magdalena, río Magdalena dr. (Atlantic), ca. 10°23′N, 075°08′W. Chocó. BMNH 1910.7.11.217, 1, 99 mm, río Condoto, río San Juan dr. (Pacific), ca. 05°04′N, 076°40′W. BMNH 1914.5.18.94-98, 6 (syntypes), 41-105 mm, río Condoto, río San Juan dr. (Pacific), ca. 05°04′N, 076°40′W, 1914, H. Spurrell. BMNH 1915.10.1.10, 1, 123 mm, Andagoya, río San Juan, río San Juan dr. (Pacific), ca. 05°05′N, 076°43′W. BMNH 2012.6.13.1, 1 (syntype), 147 mm (see Fig. 35b ), same collection data as BMNH 1914.5.18.94-98. CAS 72219, 3, 85-132 mm, Managru, upper río Quito, río Atrato dr. (Atlantic), ca. 05°20′N, 076°43′W. CAS 72227, 3, río Truando, río Atrato dr. (Atlantic), ca. 07°09′N, 077°12′W. CAS 72229, 2, FMNH 56792, 1, 121 mm, creek nr. mouth of río Guineo, affl. río Calima, río San Juan dr. (Pacific), ca. 04°04′30″N, 077°02′50″W. FMNH 56779, 3, 80-163 mm, Managrú, rio Atrato dr. (Atlantic), ca. 05°20′N, 076°43′W. FMNH 56787, 2, 86-128 mm, Truando [río Truando], rio Atrato dr. (Atlantic), ca. 07°09′N, 077°12′W. FMNH 56789, 2, 90-98 mm, Raspadura [probably Boca de Raspadura and not Raspadura, Nariño because C. E. Wilson 1913-1914 collections were all in vicinity of Quibdó, Chocó], affl. río Paimado, río Atrato dr. (Atlantic), ca. 05°16′N, 076°42′W. FMNH 56790, 1, 92 mm, Quibdó, río Atrato dr. (Atlantic), ca. 05°41′N, 076°39′W. FMNH 70885, 1, 117 mm, Pangala, ca. 40 km N Palestina, río San Juan dr. (Pacific), ca. 04°31′N, 076°59′W. IAVH-P 6812, 2, IAVH-P 6814, 2, IAVH-P 6816, 1, IAVH-P 6817, 1, IAVH-P 6820, 1, IAVH-P 7019, 1, immature, 80 mm, IAVH-P 7020, 13 (8 immature, 38-131 mm, 3 female, 105-134 mm, 2 male, 93-140 mm), mun. Yuto, quebrada Josefa 0.5 km Yuto, río Atrato dr. (Atlantic), 05°31′58″N, 076°38′04″W. IAVH-P 6813, 3, IAVH-P 6815, 1, IAVH-P 6818, 3, IAVH-P 6819, 4, IAVH-P 6821, 1, mun. Yuto, río Yuto, río Atrato dr., ca. 05°30′N, 076°39′W. IAVH-P 7017, 13 (11 immature, 41- 120 mm, 1 female, 146 mm, 1 male, 144 mm), mun. Quibdó, quebrada Samurindó, 0-0.5 km upstream bridge on Quibdó-Yuto rd., río Atrato dr. (Atlantic), 05°34′24″N, 076°37′13″W. IAVH-P 7021, 27 (13 immature, 31-98 mm, 10 female, 90-134 mm, 5 male, 105-140 mm), IAVH-P 7022, 12 (9 immature, 46-102 mm, 2 female, 112-160 mm, 1 male, 162 mm), quebrada Jigudat, 5 km S Yuto on Quibdó- Certegui rd., río Atrato dr. (Atlantic), 05°30′57″N, 076°37′48″W. IAVH-P 7410, 1, mun. Riosucio, caño Sautata, río Atrato dr. (Atlantic), ca. 07°50′N, 077°04′W. IAVH-P uncat. Ict- 1.1.18, 6, 99-142 mm, IAVH-P uncat. Ict-1.1.19, 2, 130-131 mm, IAVH-P uncat. Ict-1.3.1, 1, 162 mm, IAVH-P uncat. Ict-1.3.2, 9, 95-162 mm, IAVH-P uncat. Ict-1.3.3, 3, 104-173 mm, nr. Yuto, río Atrato dr. (Atlantic), ca. 05°31′N, 076′38″W. IAVH-P uncat. 12, 155-270 mm, río San Juan dr. (Pacific), no coordinates. NRM 10699, 2, 75-194 mm, headwaters of río San Juan, río San Juan dr. (Pacific), ca. 05°15′N, 076°39′W. NRM 27728, 4, 74-123 mm, quebrada Tuaró, close to La Victoria on Pan-American hwy., río Baudó dr. (Pacific), no coordinates [listed coordinates 05°32′N, 076°00′W, not located in río Baudó dr.]. NRM 27729, 1, 126 mm, NRM 27736, 5, 63-137 mm, NRM 30659, 2, 52-78 mm, Pie de Pepé, río Pepé, affl. río Baudó, río Baudó dr. (Pacific), 05°08′59″N, 076°47′00″W. NRM 27735, 5, 56-130 mm, Chaparra Idó, beneath waterfall, Tutunendo-San Francisco de Ichó rd., río Atrato dr. (Atlantic), 05°46′58″N, 076°32′02″W. NRM 27747, 2, 58-70 mm, Condoto, quebrada on rd. Condoto-Soledad, 5 min from airport rd., río San Juan dr. (Pacific), ca. 05°06′N, 076°40′W. Córdoba. NRM 46106, 1, 153 mm, 3 km E Urrá Hydropower Station, quebrada Santa Ana, río Sinú dr. (Atlantic), 08°00′40″N, 076°10′48″W. Santander. CAC-CDMB 129, 1, 132 mm, mun. Barrancabermeja, río Sogamoso, río Magdalena dr. (Atlantic), ca. 07°13′N, 073°55′W [coordinate for mouth of río Sogamoso]. Valle del Cauca (localities from Pacific drainages). CAS 72223, 3, río Calima, río San Juan dr., no coordinates. FMNH 56791, 2, 140-174 mm, creek nr. mouth of río Calima, río San Juan dr., ca. 04°08′N, 077°08′W. IMCN 2248, 2, 132-158 mm, quebrada La Sardiña, affl. río Dagua, río San Cipriano dr., ca. 03°51′N, 076°52′W. IMCN 4523, 5, quebrada El Venado at Cordoba, río San Cipriano dr., 03°52′28″N, 076°55′33″W. NRM 27751, 1, 90 mm, Sabaletas, río Sabaletas and streams upstream Sabaletas, rio Anchicayá dr., 03°44′N, 076°58′W. Region not specified. CU 71934, 4, no locality, no coordinates. Costa Rica (localities from Atlantic drainages). Limón. ANSP 163126, 4, 125-164 mm, creek on rd. from Bribri to Suretka, 6.0 km W Bribri, río Sixaola dr., 09°37′36″N, 082°52′44″W. ANSP 163170, 4, 103- 131 mm, río Carbón, at Sixaola-Limon rd. 7.0 km NE Bribri, río Carbón dr., 09°39′45″N, 082°48′15″W. ANSP 163176, 10 (5 measured, 107-211 mm), ANSP 163760, 2, 134-156 mm, ANSP 163762, 1, 133 mm, creek crossing rd. 0.9 km W Shiroles, affl. río Telire, río Sixaola dr. (Atlantic), 09°33′56″N, 082°55′59″W. ANSP 163190, 6, 154-183 mm, ANSP 163205, 1, 129 mm, Suretka, creek crossing old Bribri-Suretka rd., río Sixaola dr., ca. 09°37′N, 082°51′W. ANSP 163761, 3, 113-154 mm, stream at Suretka rd., 1.4 km W Bambu, no coordinates. NCSM 44973, 2, Canton Talamanca, nr. Bratsi, affl. río Telire, río Sixaola dr. (Atlantic), 09°33′41″N, 082°53′27″W. Panama. Bocas del Toro. UF 19727, 2, female, 121-134 mm, unknown river entering Almirante Bay, mi. 5 along rd. from Almirante (Atlantic), ca. 09°15′N, 082°21′W. Bocas del Toro: Comarca Ngobe-Buglé (localities from Atlantic drainages). BMNH 1925.3.6.229.238, 10 (3 immature, 137-176 mm, 4 female, 103-153 mm, 3 male, 159-278 mm), FMNH 59196, 5, 109-155 mm, UMMZ 145687, 2, 125-170 mm, UMMZ 145688, 4, 97-200, UMMZ 145689, 4, 105-200 mm, creek nr. Konkintu, río Cricamola dr., ca. 08°51′N, 081°49′W. CAS 67704, 4, 116-225 mm, Guibari creek, below Konkintu, río Cricamola dr., ca. 08°51′N, 081°49′W. CAS 67721, 1, CAS 72230, 7, “Nomormen [label unclear] creek” above Konkintu, Cricamola dr., ca. 08°51′N, 081°49′W. CAS 67722, 1, CAS 67723, 2, creeks nr. Konkintu, Cricamola dr., ca. 08°51′N, 081°49′W. ROM 89751, 2, 206-214 mm, STRI 7724, 3, 152-203 mm, caño Chalite, stream at mouth of Poman Creek, río Cricamola dr., 08°54′13″N, 081°52′53″W. ROM 89752, 3, 139-207 mm, ROM 89754, 8, 119-222 mm, STRI 7725, 9, 80-202 mm, stream nr. Bisira, río Cricamola dr., 08°54′14″N, 081°51′27″W. ROM 89755, 1, 203 mm, ROM 89756, 2, 72-175 mm, STRI 7727, 2, 118-183 mm, small stream affl. río Uyama, río Uyama dr., 09°08′58″N, 082°19′33″W. ROM 89757, 3, 102-188 mm, STRI 7728, 4, 55-131 mm (09°08′21″N, 082°18′26″W), ROM 89758, 3, 64-142 mm (09°08′17″N, 082°18′31″W), stream at village (Baisiro?), off rd. from Almirante to Punta Peña, río Uyama dr. ROM 89759, 5, 83-231 mm, STRI 7729, 5, 98-195 mm, stream affl., río Robalo, río Robalo dr., 09°00′27″N, 082°18′49″W. ROM 89760, 4, 119-241 mm, ROM 89786, 1, 182 mm, small creek, N Almirante, río Changuinola dr., 09°20′04″N, 082°28′56″W. STRI 7730, 4, 81-195 mm, stream on Almirante to Punta Peña rd., 08°58′24″N, 082°12′23″W. UF 183793, 10, 58-163 mm, Reserva Indígena de Cricamola, río Cricamola dr., 08°56′18″N, 081°54′15″W. USNM 302016, 1, 187 mm, río Changuinola dr., ca. 09°24′ N, 082°26′W. Chiriquí (localities from Pacific drainages). AUM 32356, 1, 202 mm, 10 km ESE Tolé on Pan American hwy., río Tabascara, río Vigui dr., 08°12′27″N, 081°35′07″W. Coclé. ANSP 151058, 1, 127 mm, río Chorrera at Inter-American hwy., between Penonome and Anton, río Chorrera dr., ca. 08°26′N, 080°19′W. AUM 31594, 2, 130-146 mm, Pan American hwy., 3 km SSE Chorrerita, río Hondo dr., Bahia de Parito (Pacific), 08°28′18″N, 080°19′25″W. Colón. ANSP 99880, 1, 75 mm, Canal Zone, río Agua Salud, creek on pipeline rd. nr. Gamboa, río Gatun dr. (Atlantic), ca. 09°11′N, 079°47′W. ANSP 104216, 1, 115 mm, coastal stream at Lagarto (Palma Nueva [Palmas Bellas]), W Canal Zone, río Lagarto dr. (Pacific), ca. 09°13′N, 080°04′W. ANSP 147048, 1, 163 mm, brook 7 km inland from Portobelo, Pacific coastal dr., ca. 09°31′N, 079°37′W. AUM 32118, 9, 132-170 mm, Pipeline rd. at km 4.6, Colón, río Frijoles, río Chagres dr. (Atlantic), 09°09′08″N, 079°44′06″W. FMNH 32034, 1, 69 mm, creek above Monte Líria, río Gatún dr. (Atlantic), ca. 09°16′N, 079°47′W. INHS 68132, 6, 69-99 mm, Parque Nacional Soberania, Tower Creek, río Chagres dr. (Atlantic), ca. 09°08′N, 079°41′W. INHS 68142, 1, 68 mm, INHS 68152, 8, Parque Nacional Soberania, río Frijolito, río Chagres dr. (Atlantic), ca. 09°09′N, 079°44′W. INHS 68180, 17, 33-135 mm, Parque Nacional Soberania, Tayra creek, río Chagres dr. (Atlantic), ca. 09°08′N, 079°41′W. MCP 27107, 5, 40-131 mm, río Frijoles, N Gamboa on pipeline rd., río Chagres dr. (Atlantic), ca. 09°12′N, 079°33′W. MPEG 1103, 7, to 170 mm, MPEG 1104, 13, 85-160 mm, MPEG 1106, 7, to 150 mm, Canal Zone, Gamboa hwy., nr. “2 nd ” bridge, no coordinates. USNM 293085, 7, 55-121 mm, río Pingandi, 1km above Pueblo Mandinga, río Mandinga dr. (Atlantic), ca. 09°28′N, 079°06′W. Darién. INHS 36100, 1, 120 mm, río Iglesia, Gulf of San Miguel (Pacific), 08°25′23″N, 078°00′05″W. SU 54431, 1, Pito, coastal stream (Atlantic), ca. 08°41′N, 077°31′W. USNM 293202, 1, 171 mm, rio Tuira 0.5 km above community Boca de Cupe, río Tuira dr. (Pacific), ca. 08°02′N, 077°34′W. Panamá. ANSP 104116, 1, 104 mm, creek at bridge on Interamerican hwy., ca. 9 mi. E río Pacora dr. (Pacific), ca. 09°08′N, 079°09′W. ANSP 104239, 1, 134 mm, creek (río Cristal) on bridge on Inter-American hwy. between Chorrera and Arraijan (Pacific), ca. 08°54′N, 079°44′W. ANSP 104436, 1, 142 mm, creek ca. 5 mi. W El Llano rd., río Bayano dr. (Pacific), ca. 09°12′N, 078°51′W [coordinates for El Llano]. ANSP 151021, 1, 191 mm, río Canitas at Inter-American hwy., ca. 10.4 km W Bayano bridge, río Chepes dr. (Pacific), 09°13′05″N, 078°52′38″W. FMNH 32033, 1, 162 mm, El Capital, río Mamoni, río Mamoni dr. (Pacific), ca. 09°07′N, 079°04′W. MCZ 45816, 10 (2 immature, 150-164 mm, 2 female, 154-162 mm, 6 male, 148- 209 mm), quebrada Jesus Cristo, affl. río Chagres, at Prince Philip rd. río Chagres dr. (Atlantic - now drains to Panama Canal), ca. 09°07′N, 079°42′W. ROM 89765, 2, 69-192 mm, STRI 7741, 2, 71-75 mm, río Terable, upstream from Inter-American hwy., río Bayano dr. (Pacific), 09°13′34″N, 078°58′26″W. ROM 89768, 2, 54-58 mm, STRI 7743, 2, 63-66 mm, río Terable, upstream from Inter-American hwy., río Bayano dr. (Pacific), 09°13′34″N, 078°58′27″W. ROM 89769, 4, 65-179 mm, STRI 7745, 2, 83-169 mm, río Cañita, upstream from Inter-American hwy., río Bayano dr. (Pacific), 09°13′10″N, 078°50′54″W. ROM 89771, 3, 82-186 mm, STRI 7747, 4, 78-110 mm, stream crossing rd. through Tecal forest, off Inter-American hwy., affl. río Chachare, río Bayano dr. (Pacific), 09°12′41″N, 079°03′14″W. ROM 89772, 1, 84 mm, small stream crossing rd. to río Mamoni off Inter-American hwy., affl. río Mamoni, río Bayano dr. (Pacific), 09°11′55″N, 079°04′19″W. ROM 89773, 5, 113-146 mm, STRI 7749, 5, 111- 132 mm, quebrada Tapagrilla, río Bayano dr. (Pacific), 09°09′00″N, 079°10′48″W. STRI 7744, 1, 88 mm, río Cañita below dam, río Bayano dr., 09°12′35″N, 078°53′55″W. SU 24769, 6, Canal Zone, Three Rivers Plantation, Gatun Lake, río Chagres dr. (Atlantic - now drains to Panama Canal), ca. 09°10′N, 079°51′W. UF 12979, 3, female, 74-109 mm, creek 11 mi. S Chepo, on rd. to El Llano [río Pacora dr.?], (Pacific), ca. 09°08′N, 079°12′W. UF 12995, 1, female, 135 mm, creek 5 mi. S Tocumen Airport on Inter-American hwy., small coastal dr. (Pacific), ca. 09°02′N, 079°24′W. USNM 78764, 1, 150 mm, El Capitán, río Mamoni, río Bayano dr. (Pacific), ca. 09°12′N, 079°03′W. USNM 78765, 1, 145 mm, Largataria, rio Chagres dr. (Atlantic), ca. 09°12′N, 079°39′W. USNM 293144, 3, 44-140 mm, small stream, Cartí rd., 15 km N Pan-American [Inter-American hwy.], río Bayano dr. (Pacific), ca. 09°17′N, 078°58′W. USNM 302009, 4, 82-174 mm, creek about 2 mi. E El Llano rd., río Chepo dr. (Pacific), ca. 09°13′N, 078°56′W. USNM 302012, 2, 70- 117 mm, Canal Zone, creeks of río Cocoli, W Canal, río Cocoli dr. (Pacific), ca. 08°59′N, 079°36′W. USNM 302018, 3, 92-109 mm, creek at bridge on Inter-American hwy., ca. 9 mi. E río Pacora, ca. 09°09′N, 079°09′W. USNM 302019, 1, 120 mm, creek 1 mi. W El Llano, río Bayano dr. (Pacific), ca. 09°12′50″N, 078°59′20″W. San Blas - Comarca Guna Yala (locations from Atlantic drainages). ANSP 151073, 1, 91 mm, stream on El Llano-Cartí rd., 15.9 km Inter-American hwy., no coordinates. INHS 36074, 2, 110-125 mm, Western San Blas Mountains, río Azucar dr., 09°24′N, 078°38′W. MCZ 88603, 1, 110 mm, quebrada Sigdi at Pingandi, río Mandinga dr., ca. 09°27´N, 079°05´W. MCZ 88604, 2, 105-110 mm, marsh, río Mandinga, 4-5 km above mouth, río Mandinga dr., ca. 09°28′N, 079°03′W. USNM 293152, 5 (1 CS), 77-160 mm, río Cartí, 3 km Cartí, río Cartí dr. (Atlantic), ca. 09°26′N, 078°58′W. USNM 293154, 7, 58-114 mm, río Cangandi, ca. 3 km above confl. with río Mandinga, río Mandinga dr., ca. 09°26′N, 079°05′W. USNM 293155, 2, 130-145 mm, 2 km. E Cangandi village, quebrada Dolati, affl. río Cangandi, río Mandinga dr. ca. 09°26′N, 079°05′W. USNM 302001, 7 (1 CS), 102-135 mm, río Chucubti, nr. Obaldía [Puerto Obaldía], río Chucubti dr. ca. 08°39′N, 077°25′W. Veraguas (locations from Pacific drainages). ANSP 99922, 2, 73-80 mm, creek at bridge ca. 9 mi. W El Maria on Sona-Remedios rd., río Tabasara dr., ca. 08°01′N, 081°32′W. ANSP 104031, 1, bridge ca. 17 mi. W Santiago on rd. to Sona, río San Pablo dr., ca. 08°03′N, 081°10′W. ANSP 104087, 1, 215 mm, stream on Sona-Remedios rd., ca. 2 mi. W El Maria, río Tabasara dr., ca. 08°01′N, 081°27′W. ANSP 104173, 1, 120 mm, creek at bridge ca. 9 mi. from Santiago on rd. to San Francisco, río Santa Maria dr., ca. 08°12′N, 080°57′W. AUM 32145, 1, 174 mm, 1 km SE Sona on rd. to Santiago, affl. río San Pablo, río San Pablo dr., Golfo de Montijo, 08°00′15″N, 081°17′09″W. USNM 302000, 1, 217 mm, no coordinates (Pacific dr.). USNM 302010, 1, 170 mm, ca. 7 mi. S Santiago de Veraguas, bridge on Ontijo rd., río San Martin Chiquito, río San Pedro dr., ca. 07°59′N, 080°58′W. USNM 302020, 4 (2 measured), 183-208 mm, creek 1 mile S Santa Fé, río Santa Maria dr., 08°29′40″N, 081°04′33″W. USNM 302023, 1, 157 mm, creek 20 mi. W Santiago de Veraguas, on Inter-American hwy., río San Pablo dr., 08°11′55″N, 081°13′50″W. USNM 302024, 2, 120-131 mm, río Conaco, ca. 16 mi. E Santiago, río Santa Marta dr., ca. 08°06′N, 080°44′W. Region not specified. CAS 50274, 1, 53 mm, no locality/coordinates. CU 71935, 7, no locality/coordinates. CU 71936, 27, no locality/ coordinates. MZF-Manitoba 499, 4, 104-110 mm, no locality/ coordinates. Venezuela (localities from Atlantic drainages). Mérida. MBUCV-V 8991, 2, female, 144-146 mm, mun. Alberto Adrianis, río Guayabones, affl. río Chama, lago de Maracaibo dr., ca. 08°34′N, 071°41′W. Táchira (localities from lago de Maracaibo drainages). MBUCV-V 10877, 2, 90-97 mm, stream between El Vigía and La Fría, affl. río Zulia, affl. río Catatumbo, ca. 08°12′N, 072°15′W [coordinates for La Fría]. MHNLS 1866, 4, 47-105 mm LEA, MHNLS 1867, 4, 62-100 mm LEA, MHNLS 1868, 4, El Vigía hwy., at La Fria, río Zulia, affl. río Catatumbo, ca. 08°12′N, 072°15′W (listed by Sullivan, 1997). Trujillo. INHS 59921, 1, 92 mm, 2 km S La Victoria on hwy. 1, río Caus, lago de Maracaibo dr., ca. 09°19′N, 070°51′W. MBLUZ 3766, 1, Pan American hwy., río Villegas at Puente Villegas, affl. río Bucare, río Tocuyo dr., ca. 09°45′N, 070°14′W (listed by Sullivan, 1997). MCNG 24898, 1, 136 mm LEA, quebrada Catalina, stream in Flor de Pátria, lago de Maracaibo dr., ca. 09°27′, 070°28′W (listed by Sullivan, 1997). Zulia (localites from lago de Maracaibo drainages). INHS 34708, 1, 103 mm, stream S Machiques, 09°45′00″S, 072°30′42″W. INHS 35365, 2, 108-114 mm, 18 km. N Puerto Catatumbo at hwy. 6, bridge over caño Taguara, affl. río Santa Ana, 09°17′22″N, 072°32′49′W. INHS 60283, 1, 98 mm, 12 km intersection hwy. 6 and hwy. 2, río Zulia, ca. 08°23′N, 072°23′W. MBLUZ 2645, 1, Mara District, nr. El Sargento, flooded area of río Limon, no coordinates (listed by Sullivan, 1997). MBLUZ 3937, 3, caño Ictobogui at Aragtoba, Sierra de Perija, no coordinates, ca. 09°44′N, 072°52′W (listed by Sullivan, 1997). MBLUZ 4274, 2, unnamed stream, Parque Sierra de Perija, ca. 09°44′N, 072°52′W (listed by Sullivan, 1997). MBUCV-V 2935, 3, female, 155-160 mm, río El Quebradón, between Caja Seca and Aguas Calientes, ca. 09°04′N, 071°10′W. MBUCV-V 9328, 2, 75-150 mm, mun. Jesús María Semprún, Hacienda El Encantado, stream affl. río Zulia, ca. 08°45′N, 072°20′W. MBUCV-V 14046, 7, 68-161 mm, Catatumbo region, base of Sierra Azul, río Catatumbo, ca. 08°54′N, 072°26′W. MBUCV-V 14112, 59, 38-93 mm, MBUCV-V 15067, 18, 33-68 mm, District of Perijá, Cañada Riecito, río Guaco, ca. 09°48′N, 072°12′W. MCNG 24884, 1, 125 mm LEA, río Chiquito, ca. 10°13′N, 071°02′W (listed by Sullivan, 1997). UF 21796, 1 ( CS), 120 mm, stream about 10 km N Mene Grande, ca. 09°55′N, 070°55′W. UF 25444, 1, 179 mm, prov. Libertad, stream, path to La Misión de los Ángeles, ca. 10°32′N, 071°27′W. UMMZ 56099, 2, 124-176 mm, La Fría, Pueblo Nuevo, ca. 08°57′N, 071°36′W. USNM 121584, 8, 50-115 mm, 12 km S Rosário, río San Juan, ca. 10°12′N, 072°19′W. USNM 121585, 11 (2 lost during CS), 69-177 mm, río San Juan at bridge, affl. rio Motatán [presumably río Motatán de los Negros, not río Motatán, listed in Trujillo State], no coordinates. USNM 121586, 17, 62-143 mm, USNM 348532, 15, 93-165 mm, río San Pedro at bridge, affl. río Motatán, no coordinates. Country not specified. ANSP 22980, 2, 118-178 mm, New Grenada [Colombia, Panama and parts of Ecuador and Venezuela prior to 1858], no coordinates.

Figures

Fig. 35. Brachyhypopomus occidentalis. a. NRM 27736, immature, 131 mm TL (head in lateral view, and body in lateral and dorsal view, specimen fixed in formalin and preserved in EtOH); Colombia, rio Baudó dr. b. BMNH 2012.6.13.1, largest syntype specimen, sex not determined, 147 mm TL (body in lateral view, specimen preserved in EtOH, note damage and subsequent regeneration to caudal filament); Colombia, río San Juan dr. c. IAVHP 7022 (WC04.230905), male, 162 mm TL. d. IAvHP 7022 (WC03.230905), female, 112 mm TL, non-type (bodies in lateral view, live individuals); Colombia, río Atrato dr. Note sexual dimorphism in caudal-filament length and height in c (male) & d (female). Scale bars = 5 mm.

Fig.36. CollectionrecordsforBrachyhypopomusoccidentalis (circles) and B. palenque (squares). The lectotype location for B. occidentalis and holotype location for B. palenque are marked with open symbols. Elevation data refers to altitude above mean sea level (see Fig. 2 for legend).