Mazarunia pala, López-Fernández & Taphorn & Liverpool, 2012

López-Fernández, Hernán, Taphorn, Donald C. & Liverpool, Elford A., 2012, Phylogenetic diagnosis and expanded description of the genus Mazarunia Kullander, 1990 (Teleostei: Cichlidae) from the upper Mazaruni River, Guyana, with description of two new species, Neotropical Ichthyology 10 (3), pp. 465-486 : 479-481

Mazarunia pala , new species

Figs. 2b , 3b , 6a , 11-13

Mazarunia sp. 2 López-Fernández et al., 2010: 1072, 1075, 1077, 1079-1081 [relationships within Geophagini].

Holotype. UG/ CSBD 1668 (ex-ROM 89675), 62.7 mm SL, Guyana, Cuyuni-Mazaruni (Region 7), upper Mazaruni River, backwater channel on right bank in front of Warwata village, near mouth of Kamarang River , 5°51’56.8074”N, 60°36’32.076”W, 24 Mar 2011, H. López-Fernández, D.C. Taphorn & E. Liverpool.

Paratypes. Guyana, upper Mazaruni River , Cuyuni-Mazaruni (Region 7) : ROM 89658 , 4 , 32.5-74.2 mm SL (all measured), Mazaruni River Warwata village, near mouth of Kamarang River (same locality as HLF11-32), 16 Mar 2011, 5°51’56.8074”N, 60°36’32.076”W, H. López-Fernández, D. C. Taphorn & E. Liverpool & S. Refvik . ROM 89675 , 3 , 37.1-64.2 mm SL (1, 47.7 mm SL), collected with holotype ; ROM 89737 , 4 , 40.1-72.8 mm SL (all measured), Mazaruni River, channel on left bank, downstream from Kamarang , 1 km upstream from Membaru, 5°55’1.776”N, 60°36’13.4994”W, 13 Mar 2011, H. López-Fernández, D.C. Taphorn, E. Liverpool, S. Refvik & K. Kramer . ROM 83753 , 7 , 39.5-48.2 mm SL (6, 39.5-44.1), Mazaruni River , sandy beach and associated embayment both created by gold-mining dredging, 5°41’35.412”N, 60°28’11.784”W, 18 Apr 2008, H. López-Fernández, D.C. Taphorn, E. Liverpool, & C. Thierens . ROM 83870 , 4 , 20.4-56.8 mm SL (3, 38.0-56.8), Mazaruni River, beach on Mazaruni River downstream from Kamarang , 5°56’10.1034”N, 60°36’53.7834”W, 24 Apr 2008, H. López-Fernández, D.C. Taphorn, E. Liverpool, & C. Thierens . ANSP 192032 (Ex. ROM 89737 ), 1, 53.2 mm SL, Mazaruni River, channel on left bank, downstream from Kamarang , 1 km upstream from Membaru, 5°55’1.776”N, 60°36’13.4994”W, 13 Mar 2011, H. López-Fernández, D. C. Taphorn, E. Liverpool, S. Refvik & K. Kramer .

Diagnosis. Mazarunia pala can be distinguished from all other cichlids by the generic diagnostic characters. Phylogenetic analysis revealed that M. pala can be distinguished from its congeners by the derived absence of a parhypurapophysis (132-1), and externally, it is diagnosable by the presence of a dorsal-fin scaly pad with ctenoid scales (vs. no scaly pad in M. charadrica and M. mazarunii ), a small suborbital stripe that is limited to the preopercle, by the absence of clearly discernible lateral bars on the body, and by its general pinkish coloration with a midlateral spot as the only melanic marking.

Description. Measurements are summarized in Table 1. No obvious sexual dimorphism. Head slightly broader ventrally. Dorsal head profile ascending from snout to vertical through posterior margin of orbit, angle more pronounced as body size increases, gently convex between tip of snout and orbit, where slightly concave, or profile gently concave in largest specimens (52.2 and 73.4 mm SL); ascending to dorsal-fin origin, but less steeply; dorsal base convex, ascending to about 7 th spine, then gently descending to last dorsal ray; dorsal profile of caudal peduncle straight to slightly concave to caudal-fin base. Ventral head profile straight or very slightly convex, descending to pelvic-fin insertion, flat to anus, then ascending through anal-fin base, most steeply through last 3-4 anal-fin rays to anal insertion; caudal peduncle gently ascending, slightly concave to caudal-fin base. Upper lip about half as wide as lower; lower lip widest in anterior half, covering distal portion of upper lip when mouth closed. Lower lip fold broad, discontinuous at dentary symphysis. Maxilla reaching from one fifth to one third of distance between nostril and orbit. Opercle, preopercle, cleithrum, supracleithrum and post-temporal smooth.

E1 24(3), 25(15)*, 26(1); scales between upper lateral line and dorsal fin 3(2), 3½(17)* anteriorly and 1(1), 1½ (10)*, 2(5), 2½(3) posteriorly. Scales on upper lateral line 15(1), 16(8), 17(9)*, 18(1), and lower lateral line 6(1), 7(7), 8(9)*, 9(2). Circumpeduncular scale rows 7 above, 7 below lower lateral line, ctenoid. Two scale rows between lateral lines. Opercle fully scaled, ctenoid, subopercle and cheek fully scaled, cycloid; interopercle caudally scaled, cycloid. Occipital and flank scales ctenoid. One column of postorbital scales, ctenoid. Lateral chest scales ctenoid, smaller than flank scales. Dorsal fin naked with narrow, ctenoid scaly pad along base of soft portion; anal, pectoral and pelvic fin naked; caudal fin with single row of ctenoid scales between rays, covering one fifth to one quarter of fin length. Accessory caudal-fin extensions of lateral line restricted to one tubed scale at base of dorsal-fin between D3 and D4 and ventrally between V4 and V5.

Dorsal fin rays XV,7(2), XVI,7(3), XVI,8(5)*, XVII,7(7), XVII,8(2); anal III,7(10), III,(9)*. Dorsal spines increasing in length from first to 8 th, then approximately equal or slightly increasing to last, which is longest; membranous lappets behind all spines. Soft portion of dorsal fin pointed, 4 th ray longest, often slightly produced in larger (>50.0 mm SL), reaching no more than half of caudal-fin length. Caudal fin symmetrical, distal margin slightly rounded. Anal fin pointed, 4 th ray slightly produced in large specimens (>60.0 mm SL), reaching about quarter of caudal-fin length. Pectoral fin asymmetrical, rounded dorsally and caudally, 4 th ray longest; tips of longest rays barely reaching anus but not pelvic-fin rays or anal-fin origin. Pelvic spine about half length of first ray, which is longest and produced into filament reaching first or second anal-fin spine, each subsequent pelvic-fin ray shorter till last, which is about one third length of longest.

Outer premaxillary hemiseries with 7 to 13 thin, sharp, slightly recurved, unicuspid teeth, progressively smaller distally from symphysis. Four irregular rows of smaller, unicuspid teeth, separated from outermost row by wide gap. Dentary hemiseries with 15 to 20 teeth in outer row diminishing in size caudally, 2 to 3 inner rows with smaller teeth separated from outermost row by gap which progressively diminishes caudally, teeth in inner rows eventually join outer line. Dentary hemiseries separated by small symphyseal gap, particularly in two outermost rows.

External rakers on first gill arch 9(1), 10(3), 11(10), 12(5)*. Lower pharyngeal tooth plate ( Fig. 6c ) wider than long, length of bone 86% of width; dentigerous area 74% of width, 67% of length; 14-15 teeth in posterior row; 8 in median row. Teeth thin, flattened laterally, unicuspid anteriorly and bicuspid postero-medially; cusps arranged antero-caudally with main cusp at tip of tooth and smaller anterior and lower to main; cusps straight to slightly recurved; anterior teeth more cylindrical than posterior. Two tooth plates on fourth ceratobranchial. Vertebrae 12+14=26(6).

Color in alcohol. Figs. 11-12 . Base color light pinkish-brown; snout, region between posterior margin of maxilla to eye and top of head near supraoccipital darker brown or gray, black just posterodorsal to orbit, forming “cap” on top of head, markedly delimited ventrally from dusky beige preopercle, chin and throat, opercle beige ventrally, darker brown dorsally ventral margin of preopercle darker than rest of bone. Groove from posterior nares to anterior margin of eye light beige. Lips whitish. Infraorbital stripe absent. Branchiostegal membrane brown, contrasting with light chest. Body countershaded, darkest at dorsal midline, most scales with lighter centers, outlined with brown, body lightest on chest below pectoral fin. Light centers of scales align forming alternating rows of light spots, and thin, darker horizontal stripes, most notable on caudal peduncle. Flanks without welldefined vertical bars in adult or juveniles. Scaled third of caudal-fin base dark brown with white spots on scale centers. Caudal peduncle with very diffuse gray blotch, traces of third and fourth vertical bars of other species expressed as just faint blotches centered on E1 scale row. Midlateral blotch under tips of dorsal pectoral-fin rays; about five scales wide and three high, continuous with dark brown pigment along lateral midline, continuing anteriorly onto opercle. Slight trace of vertical bar from dorso-posterior margin of opercle to dorsal midline, united ventrally with brown pigment of opercle. Spinous portion of dorsal fin and proximal part of membranous portion maroon to brown, rest of fin dusky gray, rays of soft dorsal lighter than membranes distally, no light or dark spots. Caudal fin gray, rays lighter than membranes, darkest distally. Anal fin maroon to brown with darker pigment along rays. Pelvic fin dusky white, first rays black. Pectoral fin hyaline.

Color in life. From live specimens and photographs of recently captured specimens ( Fig. 13 ). Background color brown to pinkish-tan. Some scales with lighter centers, especially on posterior fourth of body, forming horizontal rows of light spots ending on caudal peduncle. Scales of side with darker margins, forming reticulate pattern. Head from tip of snout to around eye and posterior to tip of supraoccipital maroon, dark brown or gray, anteriorly tapering light stripe from anterodorsal margin of eye to nare; light patch on dorsal edge of orbit, extending one or two scales dorsally. Upper lip brown anteriorly, white laterally, lower lip whitish. Iris emerald green with golden highlights where light stripe between nare and anterior edge of orbit meets iris; dark brown of head extending under eye turning purplish on upper body behind eye and on upper portion of opercle. Distinctly golden patches behind eye and at anterior end of upper lateral line; shiny silver to golden stripe extends postero-dorsally from below orbit across upper cheek, onto upper gill cover and onto body in humeral region, where it meets lowermost of two patches of light pink scales at anterior-most upper lateral line pores. Head below eye purplish pink or maroon, opercle gray with shiny golden highlights. Body anterior to pectoral fin pink, branchiostegal membrane yellow to orange. Ventral portion of head and ventrum between pectoral-fin bases light gray with pink overtones; abdomen whitish, scales outlined with thin gray margins. Supraorbital bar extends posterodorsad from eye but not well distinguished from general color of top of head. Lateral bars not well defined, or irregular, mottled pattern of brownish-maroon and pink dorsally from E1, more or less uniformly pinkish grey below E0. Midlateral spot of darker black pigment between 8 th and 10 th dorsal spines, about 3 scales wide and 2 scales deep, entirely under upper lateral line, or barely overlapping it. Dorsal fin mostly maroon or reddish brown, first spine and distal tips of spines and membrane lappets dark gray for all of spinous portion, soft portion with maroon widely outlining rays, but transparent on distal 1/3 of soft rays. Dorsal-fin spines darker than membranes. Pectoral fin transparent, rays thinly outlined with black. Pelvic whitish or light pink, spine and anterior rays outlined in black. Anal fin maroon to pink along base then translucent or dark gray distally, latter probably reproductive adults. Caudal fin dusky gray proximally, black pigment extending along rays for about 1/3 of their lengths, membranes lightly dusky to greyish pink.

Geographic distribution. Mazarunia pala is known from four collection sites alongshore of the main channel of the upper Mazaruni River between the mouths of the Kukui and Kamarang rivers ( Fig. 7 ).

Etymology. From the Greek pala (παλα), meaning gold nugget, in reference to the golden spots behind and under the orbit. Also in reference to the fact that this species has only been collected in the main channel of the upper Mazaruni River, where a growing gold mining industry may be contributing to degradation of its habitat. To be regarded as an adjective in feminine form.

Habitat. Collected in very similar habitats to those of Mazarunia mazarunii , with which it seems to coexist, but apparently it is not as abundant as that species. Collected mostly in or near the main upper Mazaruni River channel in localities with sandy or slightly muddy substrates with structure formed by submerged or emerging grass and other riparian vegetation and some drift wood. Like the other species in the genus, M. pala appears to move at night into shallow, flooded banks with terrestrial vegetation. Temperature ranged from 21.7-24.5 ºC, dissolved oxygen levels 5.2-9.3 mg /l, pH 4.4 and vey low conductivity (<10 μS).

Figures

Fig.2. Infraorbital series in left, lateral view, illustrating morphological character 116; a) Guianacara dacrya,character state 116-1, paratype, 58.0 mm SL,ANSP 179495; b) Mazarunia charadrica, character state 116-3, 56.0 mm SL, ROM 83808; c) Mazarunia mazarunii, character state 116-3, 50.1 mm SL, ROM 83869 d) Mazarunia pala, character state 116-3, 50.8 mm SL, ROM 83753.

Fig. 3. First epibranchial and pharyngobranchial bones in right, approximately antero-dorsal view illustrating morphological phylogenetic characters 100 and 101; a) Guianacara dacrya, character states 100-0, 101-0, 58.0 mm SL, ANSP 179495; b) Mazarunia charadrica, character states 100-1, 101-2,56.0 mm SL, ROM 83808; c) Mazarunia mazarunii, character states 100- 2,101-4, 50.1 mmSL,ROM 83869d)Mazarunia pala,character states 102-0, 101-4, 50.8 mm SL, ROM 83753; UP, uncinate process of the first epibranchial; AA, anterior arm of the first epibranchial; PhB, first pharyngobranchial.

Fig. 6. Lower pharyngeal jaw of species of Mazarunia in occlusal view; a) Mazarunia charadrica, paratype, ROM 89553,67.1mm SL, b) Mazaruniamazarunii, ROM 83737,58.5 mmSL, c) Mazarunia pala,paratype, ROM 83753,43.8 mmSL.

Fig. 11. Mazarunia pala, holotype, UG/CSBD 1668, 65.2 mm SL, Guyana, Cuyuni-Mazaruni (Region 7), Mazaruni River, backwater channel on right bank in front of Warwata village, near mouth of Kamarang River.

Fig. 12. Ontogenetic changes in body shape and coloration in Mazarunia pala. a) Paratype, 52.2 mm SL, ROM 89737, b) 39.9 mmSL, ROM 89737, c)21.0 mmSL,ROM 83870.

Fig. 13. Live colors of Mazarunia pala through ontogeny.a) adult individual, probably male, 76.7 mm SL, ROM 89531, shortly after capture, b) juvenile 50.0 mm SL, ROM 89675, shortly after capture.

Fig. 7. Map of the upper Mazaruni River basin showing collection localities and known distribution of the three species of Mazarunia. Blue squares: Mazarunia charadrica, Black circles: Mazarunia mazarunii; Purple triangles: Mazarunia pala. One symbol may represent more than one collection locality.