Hyphessobrycon bussingi, Ota & Carvalho & Pavanelli, 2020

Ota, Renata R., Carvalho, Fernando R. & Pavanelli, Carla S., 2020, Taxonomic review of the Hyphessobrycon panamensis species-group (Characiformes: Characidae), Zootaxa 4751 (3), pp. 401-436 : 403-412

Hyphessobrycon bussingi , new species

(Figs. 1–6, Tab. 1)

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Hyphessobrycon panamensis (not Durbin)—. Behre, 1928: 318 [list of species, Western Panama; distribution]—. Bussing, 1966:218 [in part; lots ANSP 99920 and ANSP 99932]—. Bussing, 1987: 85 [ Costa Rica; brief description, photo, distribution]—. Bussing, 1998: 105-108 [ Costa Rica; diagnosis in key, brief description, photo, distribution]—. Lima et al., 2003: 139 [in part; listed; Costa Rica]—. Angulo et al., 2013: 992 [list of species, Costa Rica; distribution].

Holotype. UCR 3302-001, 33.7 mm SL, male (rd): Costa Rica, Limón, río Cocolis, 3.5 km southeast of Shiroles, on road Bratsi-Shiroles , 09°34’05’’N, 82°56’4.92’’W; W. A. Bussing ichthyology team, 06 Oct 1979.

Paratypes. All from Costa Rica, Limón. Río Sixaola basin: MZUSP 125290 , 15 , 27.5 –32.0 mm SL, San Miguel , Crique Azul on finca Los Laureles de ANAI, 09°33’50’’N 82°40’39.4’’W; W. McLarney, 31 Mar 1987 NUP 22293 , 9, 27.2–34.0 mm SL, stream tributary of río Gandoca, finca Elida Morales , 09°34’10’’N 82°37’19.7’’W; W. McLarney, 18 Mar 1983 ; UCR 3240001, 39, 24.4–34.0 mm SL, same data as holotype; UCR 3241001, 20, 26.4–36.0 mm SL, Mojoncito, Bratsi, stream Shiragri , 09°30’34’’N 83°00’01’’W; A. E. Corrales & C. Jiménez, 05 Jul 1982 ; UCR 3242001, 30, 26.2–29.3 mm SL, stream Ñiabri , 09°29’25’’N 82°58’24.6’’W; A. Corrales, C. Jiménez & A. Román, 12 Jun 1982 .

Non-type material. Río Sixaola basin: FMNH 144016 , 8 (2), laguna Mata de Limón , 9°34’5.06”N 82°37’46.03”W ; C. McMahan, W. Ludt, A. Angulo & M. Mafla, 09 Nov 2019; UCR 129917, 119, same data as holotype; UCR 1395007, 74, stream Ñiabri , 09°29’25’’N 82°58’24.6’’W ; A. Corrales, C. Jiménez & A. Román, 12 Jun 1982; UCR 1408001, 52, Mojoncito, Bratsi, stream Shiragri , 09°30’34’’N 83°00’01’’W ; A. E. Corrales & C. Jiménez, 05 Jul 1982; UCR 1838005, 20, stream tributary of río Gandoca, finca Elida Morales , 09°34’10’’N 82°37’19.7’’W ; W. McLarney, 18 Mar 1983; UCR 1881002, 28, San Miguel, Crique Azul on finca Los Laureles de ANAI, 09°33’50’’N 82°40’39.4’’W ; W. McLarney, 31 Mar 1987. Panama, Bocas del Toro: ANSP 99932 , 2 , 35.6–36.1 mm SL, backwaters and overflowed banks of río Guarumo at Chiriquicito , 8°57’N 82°11’W ; H.G. Loftin & R. W. Yerge, 19 Apr 1962; ANSP 104149 , 31 (5, 32.7–35.1 mm SL), río Changuinola upstream about 10 mi to first big rapid, ʽCorriente Grandeʼ , at creek & backwater, 9°30’N 82°43’W ; H. G. Loftin, 30 Sep 1962. Costa

Diagnosis. Hyphessobrycon bussingi differs from all congeners, except from H. compressus , H. diancistrus Weitzman & Palmer , H. otrynus Benine & Lopes , and those belonging to the H. panamensis species-group, by the presence of one large bony hook per fin ray, anterodorsally oriented and surrounded by a fleshy area, on last unbranched and first branched anal-fin rays of mature males (vs. absence of hooks, or presence of small and numerous hooks per fin ray). Hyphessobrycon bussingi can be distinguished from H. compressus by the absence of a black blotch on the dorsal fin (vs. presence), by the presence of predorsal series (vs. absence), and by presenting 32–34 scales in longitudinal series (vs. 41–48). It can be distinguished from H. diancistrus and H. otrynus by presenting caudal fin hyaline (vs. dark-brown blotches on caudal-fin lobes in H. diancistrus ; distal third of caudal fin darkened in H. otrynus ). It differs from H. columbianus by the absence of a silvery-blue iridescent coloration on dorsal region of flanks in life (vs. presence), and by a lower body depth (33.7–42.6% SL vs. 46.0–50.3% SL). It can be distinguished from H. savagei by presenting the second humeral blotch less conspicuous than the first, extending one or two longitudinal scale rows below lateral line, with posterior margin as a concentration of melanophores concentrated along longitudinal midlateral stripe (vs. humeral blotches evenly pigmented, extending two to four longitudinal scale rows below lateral line, with contours and margins always well-defined). It can be distinguished from H. panamensis by a higher number of branched anal-fin rays (23–27, rarely 22, mode = 24 vs. 19–23, modes = 21 and 22), and by presenting 6–7 (mode = 6½) scale rows between lateral line and dorsal-fin insertion (vs. 7–8, mode = 7). It can be distinguished from Hyphessobrycon condotensis by presenting 8–9, rarely 7 (mode = 8) gill rakers on epibranchial 1 (vs. 5–7, mode = 7), and higher dorsal- (27.8–41.2% SL vs. 27.7–29.7% SL) and pelvic-fin length (20.4–24.5% SL vs. 17.3–20.5% SL) in mature males. It differs from Hyphessobrycon daguae by presenting a well-defined first humeral blotch (vs. a single diffuse humeral blotch).

Description. Morphometric data in Table 1. Body compressed, greatest body depth slightly anterior vertical through dorsal-fin origin. Dorsal profile of body convex from upper lip to vertical through anterior nostril; straight from this point to distal tip of supraoccipital process. Slightly convex from tip of supraoccipital process to dorsal-fin origin; straight from this point to adipose-fin origin; and straight or slightly concave along caudal peduncle. Ventral profile of body convex from lower lip to anal-fin origin; straight or slightly convex along anal-fin base; and slightly concave along caudal peduncle.

Jaws equal, mouth terminal. Premaxillary teeth in two rows; outer row with 1(1), 2*(18), 3(21), or 4(13) tricuspid teeth; inner row with 4(1), 5*(44), or 6(6) tri- to pentacuspid teeth. Posterior margin of maxilla at vertical through anterior margin of pupil. Maxilla with 1(4), 2*(28), or 3(22) conical, tri- to pentacuspid teeth. Dentary with 4(21), 5*(26), or 6(1) large tri- to pentacuspid teeth, gradually decreasing in size, followed by five conical and abruptly smaller teeth. Central cusp longer than lateral ones.

Scales cycloid. Lateral line incompletely pored with 6(4), 7(9), 8(27), 9*(21), 10(2), or 11(1) perforate scales. Longitudinal series, including perforate scales, with 32(2), 33(31), or 34*(15). Scale rows between dorsal-fin origin and lateral line 6(16), 6½*(9), or 7(37). Scale rows between lateral line and pelvic-fin insertion 4(2), 4½ (9), 5*(42), or 5½(8). Predorsal series irregular*, uni or biserial, with 10(22), 11(15), or 12(4) on middline. Single row of scales covering base of anteriormost anal-fin rays. Circumpeduncular scales 13*(15) or 14(20).

Dorsal-fin rays ii,8,i(7) or ii,9*(46). First dorsal-fin pterygiophore located between neural spines of ninth and 10 th (1) vertebrae. Adipose fin present. Pectoral-fin rays i,11*(23) or 12(31), distal tip of rays reaching pelvic-fin origin. Pelvic-fin rays i,6(3) or 7*(52), distal tip surpassing anal-fin origin. Anal-fin rays iii(2) or iv*(51), 22(1), 23(6), 24*(23), 25(25), 26(11), or 27(1). Anal fin of mature males with large bony hooks. Caudal fin bifurcate, lobes approximately of same size, i,9/8,i rays.

First gill arch with 7(2), 8(44), or 9*(10) rakers on epibranchial, 1*(55) on intermediate cartilage, 11(1), 12(23), or 13*(32) on cerato+hipobranchial. Branchiostegal rays 4. Total vertebrae (32), supraneurals 4(1) ( Fig. 2 ).

Color in alcohol. Background color light brown. Dorsal region of head and middorsal region of body with dense concentration of melanophores. Region above pupil darkened. Infraorbitals and opercle beige, with few scattered melanophores, evenly distributed. Opercle retaining some guanine pigmentation. Lower portion of maxilla and gular region with few scattered melanophores, slightly concentrated on upper half. Two dark-brown humeral blotches, vertically elongated, separated by light-beige area. First humeral blotch conspicuous, extending three to four longitudinal scale rows above and one or two below lateral line. Second humeral blotch usually inconspicuous, with melanophores equally distributed, four to five longitudinal scale rows above and one or two below lateral line; posterior margin with concentration of melanophores concentrated along longitudinal midlateral stripe. Flanks with melanophores evenly distributed, except on antero-ventral half, with few or without melanophores. Posterior margin of scales on superior third of flanks with concentration of melanophores. Brownish to silvery longitudinal midlateral stripe, from second humeral blotch to caudal peduncle, more conspicuous on posterior region. Fins hyaline, with slight concentration of melanophores on distal half of dorsal fin, distal third of anal fin, and median caudal-fin rays. Abdominal region, from pectoral-fin origin to pelvic-fin end, lacking melanophores.

Color in life. Background color pale beige to silvery. Dark markings as in preserved specimens. Abdominal and region above anal fin reddish. Pelvic fin and distal margin of anal fin reddish. Adipose- and dorsal fins reddish or yellowish during the reproductive period ( Bussing, 1987, 1998, and Fig. 3).

Distribution. Hyphessobrycon bussingi is known from the río Sixaola basin, Atlantic coast of Costa Rica, and río Changuinola, río Guarumo, and río San San, Panama (Fig. 4, and 21).

Sexual dimorphism. Mature males with one large bony hook per fin ray, anterodorsally oriented and surround- ed by a fleshy area, from the last unbranched (on fourth or fifth segments) to the fifth branched (varying on fifth to seventh segments) anal-fin rays of mature males ( Figs. 5a and 6a ). One specimen presented two large bony hooks on last unbranched and first branched anal-fin rays. Very small hooks, difficult to discern, can be present on distal segments of most anterior anal-fin rays. Dorsal- and pelvic-fin length of males slightly longer than in females. Males with distal margin of anal fin almost straight, and females with distal margin of anal fin falcate, with anteriormost anal-fin rays longer than posterior ones.

Ecology and habitat. Hyphessobrycon bussingi feeds on terrestrial insects, and lives in rivers and streams with moderate flow, in altitudes ranging from 40 to 60 meters a.s.l. and with water temperatures ranging from 24–26ºC ( Bussing, 1998, as H. panamensis ).

Etymology. The specific epithet honors William A. Bussing (1933-2014), in recognition of all his contributions to the knowledge of the ichthyofauna of Costa Rica. A genitive noun.

Remarks. Hyphessobrycon bussingi was previously incorrectly identified as H. panamensis in Costa Rica and in the province of Bocas del Toro, Panama (at the border with Costa Rica) (e.g. Bussing, 1987, 1998; Angulo et al., 2013). However, both species can be diagnosed by the characters mentioned in the Diagnosis section, above.

Hyphessobrycon columbianus Zarske & Géry, 2002 (Figs. 7–8, Tab. 2)

Hyphessobrycon columbianus Zarske & Géry, 2002: 22 [original description, type locality: “ Kolumbien, Darien, kleiner Bach etwa 6 km flussaufwärts von Acandi, Einzugsgebiet des Rio Acandi, Atlantikküste”]—.Lima et al., 2003: 135 [listed; distribution]—. Zarske, 2003: 17 [type catalogue]—. Maldonado-Ocampo et al. 2008: 168 [ Colombia; Pacific slope rivers; listed]—. García-Alzate et al., 2010: 55 [diagnosis of H. sebastiani ; material examined: río Guati, Acandi, Chocó]—. Maldonado-Ocampo et al., 2012: 117 [ Colombia, Chocó; photograph; distribution] —. García-Alzate et al., 2013: 182 [diagnosis of H. chocoensis ; material examined: río Guati, Acandi, Chocó; key to species]—. DoNascimiento et al., 2017: 49 [occurrence in Colombia].

Diagnosis. Hyphessobrycon columbianus differs from all congeners by the presence of a silvery-blue iridescent coloration on dorsal region of flank in life (vs. absence of a similar color pattern). It can be further distinguished from all congeners, except from H. compressus , H. diancistrus , H. otrynus , and those belonging to the H. panamensis species-group, by the presence of one large bony hook per fin ray, antero-dorsally oriented and surrounded by a fleshy area, on last unbranched and first branched anal-fin rays of mature males (vs. absence of hooks, or presence of small and numerous hooks per fin ray). It also differs from H. compressus by the absence of a black blotch on the dorsal fin (vs. presence), by the presence of predorsal series (vs. absence), and by presenting 32–34 scales in longitudinal series (vs. 41–48). It can be distinguished from H. diancistrus and H. otrynus by presenting the caudal fin hyaline (vs. dark blotches on caudal-fin lobes in H. diancistrus ; distal third of caudal fin darkened in H. otrynus ). Additionally, it can be distinguished from the remaining species of the H. panamensis species-group by a higher body depth (46.0–50.3% SL vs. 31.8–46.5% SL).

Description. Morphometric data in Table 2. Body compressed, greatest body depth slightly anterior to vertical through dorsal-fin origin. Dorsal profile of body convex from upper lip to vertical through anterior nostril; slightly convex from this point to basis of supraoccipital; slightly concave to almost straight from base- to distal tip of supraoccipital process. Convex from tip of supraoccipital process to dorsal-fin origin; straight or slightly convex from this point to adipose-fin origin; and straight or slightly concave along caudal peduncle. Ventral profile of body convex from lower lip to pelvic-fin origin; straight or slightly convex from this point to anal-fin origin; straight to slightly convex along anal-fin base; and straight or slightly concave along caudal peduncle.

Jaws equal, mouth terminal. Premaxillary teeth in two rows; outer row with 1(1), 2(2), 3(5), 4*(2) tricuspid teeth; inner row with 5*(11) tri- to pentacuspid teeth. Posterior margin of maxilla slightly posterior at vertical through anterior margin of pupil. Maxilla with 2(4) or 3*(7) conical and tricuspid teeth. Dentary with 4(3) or 5*(6) large penta and tricuspid teeth, gradually decreasing in size, followed by 10 conical and abruptly smaller teeth. Central cusp more developed than lateral ones.

Scales cycloid, radii 2–9. Lateral line incompletely pored with 7*(1), 8(1), 9(1), 10(3), 11(2), 13(2), 16(1), or disrupted with total of 20(1) perforate scales. Longitudinal series, including perforate scales, with 32*(6), 33(5), or 34(1). Scale rows between dorsal-fin origin and lateral line 6(4), 7*(4), or 7½(4).). Scale rows between lateral line and pelvic-fin insertion 5*(5), 5½(1), 6(3), or 6½(4). Predorsal series with 9*(3), 10(8), or 11(2) scales. Single row of six scales covering base of anteriormost anal-fin rays. Circumpeduncular scales 14*(11).

Dorsal-fin rays ii,9(12) or 10*(1). Adipose fin present. Pectoral-fin rays i,10*(5), 11(7), or 12(1), distal tip of rays reaching pelvic-fin origin. Pelvic-fin rays i,6(2) or 7*(11), distal tip reaching anal-fin origin. Anal-fin rays iii* or iv(2), 22(3), 23(7), or 24*(1). Anal fin of mature males with large bony hooks. Caudal fin bifurcate, lobes approximately of same size, i,9/8,i*(3) rays.

First gill arch with 5(2), 6(7), or 7(2) rakers on epibranchial, 1(11) on intermediate cartilage, 8(1), 9(4), or 10(6) on ceratobranchial + hipobranchial. Branchiostegal rays 4.

Color in alcohol. Background coloration light brown. Dorsal region of head and middorsal region of body with dense concentration of melanophores. Region above pupil darkened. Infraorbitals and opercle beige, with scattered melanophores more concentrated on upper half. Opercle with some guanine pigmentation. Distalmost portion of maxilla and gular region with few scattered melanophores, slightly more concentrated on upper half. Two darkbrown humeral blotches, vertically elongated, separated by light-beige area. First humeral blotch conspicuous, with melanophores more concentrated on central region, extending four longitudinal scale rows above and one or two below lateral line. Second humeral blotch usually inconspicuous, with melanophores evenly distributed, extending four to five longitudinal scale rows above and one below lateral line; posterior margin with concentration of melano- phores concentrated along longitudinal midlateral stripe. Body sides with melanophores evenly distributed, except on anteroventral half, with few or without melanophores. Posterior margin of scales on superior half of flank with concentration of melanophores. Brownish to silvery longitudinal midlateral stripe, from second humeral blotch to caudal peduncle, more conspicuous on posterior region. Fins hyaline; distal half of dorsal fin, and base distal third of anal fin with more numerous melanophores. Abdominal region, from pectoral-fin origin to pelvic-fin end, with few melanophores.

Color in life. (based in Zarske & Géry, 2002, fig. 2, p. 25). Background color greenish golden. Dark markings as in preserved specimens, except for humeral blotches inconspicuous. Dorsal region of body greenish-golden. Upper half of head brown; lower half of head golden. Iris golden. Dorsal region of flank with silvery-blue iridescent coloration. Region above anal fin reddish. Abdominal region whitish-yellow. Dorsal fin reddish-yellow. Pectoral and pelvic fins hyaline. Anal fin reddish-orange. Caudal fin reddish, with distal margin darkened.

Distribution. Hyphessobrycon columbianus is known from the río Acandi (Caribbean Sea), in Colombia, and drainages of the province of San Blas, southeast Panama (Fig. 8, and 21).

Sexual dimorphism. Mature males with one large bony hook per fin ray, antero-dorsally oriented and surrounded by fleshy area, from the last unbranched to the third branched anal-fin ray of mature males. Very small hooks, which are difficult to discern, can be present on distal segments of most anterior anal-fin rays. In addition, males present a deeper body than females ( Zarske & Géry, 2002).

Material examined. 24 specimens (25.2–45.7 mm SL). Type material. MTD-F 25497, holotype, 45.7 mm SL: Colombia, Chocó, Darien region, small stream about 6 kilometers downstream from Acandi , entry of the río Acandi , Atlantic versant; Bork & Machnik leg., 20 Mar 1995 . MTD-F 25498, paratype, 40.9 mm SL, same data as holotype. Non-type material. Colombia, Chocó: DZSJRP 20155, 4, 33.4–35.9 mm SL, aquarium material. LBP 5984, 2, 33.8–37.1 mm SL, río Acandi (aquarium material); 22 Mar 2003; LBP 13555 , 3, 25.2–36.6 mm SL, aquarium material; C. Oliveira leg., 01 Sept 2012. MCNG 47820 , 1 , 31.7 mm SL, Acandi, río Guati ; S. Usma, Aug 1995 . UFRGS 14511 , 2 , 29.9–30.4 mm SL, aquarium material; C. Baicere-Silva leg., 29 Sept 2010 . Panama, San Blas: ANSP 104106 , 92 (5, 35.6–39.8 mm SL), creek of río Acla near Puerto Escoces , several miles upstream, 8°4’N 77°3’W; H.G. Loftin & S. Restrepo, 16 Dec 1962 . ANSP 104187 , 39 (5, 34.0– 36.6 mm SL), small river ‘ Ibed’ on mainland opposite island of Mulatupo , about an hour walk upstream, 8°5ʼN 77°4ʼW; H. G. Loftin & E. Eisenmann, 1 Dec 1962 .

Figures

FIGURE 2. Radiograph of Hyphessobrycon bussingi: Costa Rica, río Cocolis, UCR 3302-001, holotype, 33.7 mm SL, male.

FIGURE 5. Radiograph of anterior portion of anal fin of mature males, showing large bony hooks of: a) Hyphessobrycon bussingi (NUP 22294, 33.7 mm SL), b) H. panamensis (LBP 2759, 34.8 mm SL), c) H. savagei (UCR 4201, 24.7 mm SL). Very small hooks can be present on distal segments of most anterior anal-fin rays (white traces on a and b).

FIGURE 6. Large bony hooks on the anal fin of mature males, surrounded by fleshy area: a) Hyphessobrycon bussingi (NUP 22294, 33.7 mm SL), b) H. panamensis (LBP 2759, 34.8 mm SL), c) H. savagei (UCR 4201, 24.7 mm SL).