Garra fluviatilis, Kangrang, Punnatut, Thoni, Ryan J., Mayden, Richard L. & Beamish, F. William H., 2016

Kangrang, Punnatut, Thoni, Ryan J., Mayden, Richard L. & Beamish, F. William H., 2016, Garra fluviatilis, a new hillstream fish species (Cypriniformes: Cyprinidae) from the Kwai Noi River system, Mae Khlong basin, Thailand, Zootaxa 4175 (4), pp. 335-344 : 336-342

Garra fluviatilis sp. nov.

Fig. 2

Holotype. NIFI 5083, 67.7 mm SL; Thailand: Kanchanaburi: Mae Nam Kwai Noi drainage. Kroeng Krawai, route 323 at km 32 near Prang Phe , 14°58’17” N, 98°38’24” E, L.M. Page, R.A. Singer, R. Plongsesthee, & F.W.H. Beamish, 24 April 2011.

Paratypes. NIFI 5084 (16, 27.8–71.3 mm SL) same data as holotype . UF 181178 (8, 41.4–78.2 mm SL) same data as holotype .

Other material examined. All materials are from Thailand, Kanchanaburi Province. UF 181134 (1, 82.5 mm SL), Lichia River , Mae Nam Kwai Noi, L.M. Page et al., 24 April 2011 ; UF 173143 (6, 51.3–63.3 mm SL), stream near km 32 on Rt. 323, L.M. Page et al., 12 June 2008; UF 181317 (5, 59.8–62.5 mm SL), Ban Huay Pakkok, bridge on Kwai Noi River , P. Kangrang & F.W.H. Beamish, 26 April 2011 ; UF 176452 (18, 28.8–68.2 mm SL), Huay Lin Tin, at km 95 on 323, L.M. Page et al., 12 June 2008.

Diagnosis. Garra fluviatilis is distinguished from its congeners in having the following combination of characters: absence of proboscis, 30–33 lateral-line scales, 16 circumpeduncular scale rows, 4–5 scales from anus to anal-fin origin (anal scales), well developed upper lip with unculiferous papillae ( Fig. 3 ), presence of a pleated papilliferous fold on the lower lip, deep body with keeled nape, body width at dorsal-fin origin 12.6–17.7% SL, caudal-peduncle width 3.8–5.4% SL, laterally straight anterior margin of the anteromedial fold on the lower lip, and mottled pigmentation pattern.

Description. Morphometric and meristic data are provided in Tables 1 and 2, respectively. General external morphology is provided in Figure 2 . Mouth and lip morphology can be seen in Figure 3 . Live coloration is shown in Figure 4 . Body elongate; subcylindrical to triangular in cross-section anteriorly where body may be deep and dorsum keeled; body becoming laterally compressed posteriorly, with caudal-peduncle width less than 1/2 its height. Tip of snout to occiput uninterrupted by transverse groove or proboscis, but with slight hump immediately anterior to nares. Dorsal profile rises steadily to dorsal-fin origin or with slight hump posterior to occiput. Dorsal profile sloping downward in straight line from dorsal-fin origin to caudal base. Ventral profile flat except for a slight concavity at caudal peduncle.

Head acute when viewed laterally, rounded from dorsal or ventral perspectives. Head length about 1/4 SL, head width about 5/7 HL, orbit large, roughly 1/4 HL, interorbital distance nearly 1/2 HL. Mouth inferior, with mental disc; disc compact, about 1/4 of HL; disc roughly 2/3 as long as wide. Rostral cap folds at connection with lower lip, creating anterolateral lobe. Rostral cap covers upper jaw, often leaving lower jaw visible. Pleated papilliferous fold at junction of anterolateral lobe, anteromedial fold, and lower jaw. Two pairs of barbels; maxillary barbels roughly 2/3 length of rostral barbels.

Tubercles erect; appearing to be present on males and females, but more conspicuous in males. Tubercles in two main patches with little delimitation between them. Rostral lobe with horizontal band of small tubercles. Tubercles on lateral side of snout occurring immediately posterior and lateral to rostral lobe with small depression dividing tuberculate areas. In addition to tubercles, dorsum of head can be covered in small, subcutaneous dimples on males and females.

Intestines long, forming 7–10 concentric coils in posterior portion of abdominal cavity; coiled irregularly in anterior portion. Adipose tissue mixed in amongst intestinal coils. Gas bladder reduced, less than 1/10 SL; bladder bi-segmented and tadpole-like in shape; anterior chamber spherical, slightly larger than eye; posterior chamber long and narrow.

Dorsal-fin origin closer to tip of snout than to caudal-fin base; margin of fin slightly concave. First branched ray of dorsal fin longest; roughly equal to HL; branched fin rays 7–8. Anal fin in last quarter of body; fin rays i,5. Paired fins inserted horizontally. Pectoral fin roughly 1/4 SL; rays i,12–14. Pelvic fin roughly 1/4 to 1/5 SL; fin rays ii,7. Caudal fin forked, lobes pointed; rays 19.

Character Frequencies

Lateral-line scale rows 30(6), 31(13), 32*(13), 33(4) Predorsal scale rows 9(3), 10*(30), 11(3) Anal scales 4*(29), 5(7)

Branched dorsal-fin rays 7(1), 8*(35)

Branched pectoral-fin rays 12*(8), 13(25), 14(3) Rostral cap fimbriae 12(6), 13(8), 14(13), 15*(7), 16(2) Live coloration. Body coloration varies from light to medium bronze with small irregular dark patches ( Fig. 4 ).

Preserved coloration. In general, body mottled and marked with weakly formed blotches along lateral line; pigmentation blotches random in shape and size. In some specimens, blotches form nearly circular spots; in other specimens, blotches more diffuse and sparse, not resembling circular pattern.

Dorsum and side of head uniformly brown. Tip of snout and dorsolateral surface of rostral flap brown; pigmentation extending onto dorsal edge of rostral barbels and to base of maxillary barbels. Lower portion of head with sparse pigmentation extending ventrally, fading to immaculate in line between pectoral-fin origin and maxillary barbel.

Dorsum of body mottled; scales light to dark brown, depending on density of melanophores. No lateral stripe on body. Lateral surface mottled with nearly random pattern of weakly forming 5–7 irregular blotches anteroposteriorly. Pattern formed by heavily pigmented scales contrasting with scales with very light pigmentation. In some individuals, blotched pattern with little to no definition. Pigmented scales occurring from dorsum to four scale rows below lateral-line scale row. One scale row ventral to horizontal to pectoral-fin insertion pigmented; ventral to this point scales immaculate; venter of body around anal fin and caudal peduncle with speckled pattern formed by lightly and densely pigmented scales.

Dorsal-fin rays and membranes with little to no pigmentation; anterior margin of distal third of first ray pigmented, forming dark tip. Anal-fin rays and membranes lightly speckled at basal 1/3. First ray immaculate. Base of pelvic fin rays darkly pigmented, fading to immaculate tip. First five rays and membranes of pectoral fin dark with dense concentrations of melanophores; remaining rays and membranes as in rays of pelvic fin. Caudal-fin rays and membranes lightly pigmented with no discernable bars or stripes.

Etymology. The name, fluviatilis , is a Latin adjective meaning “of the river”, in reference to the habitat where this species lives.

Distribution. This species is currently known from tributaries to the Kwai Noi River, Mae Khlong basin in Kanchanaburi Province, Thailand ( Fig. 1 ).

Notes on habitat and biology. Garra fluviatilis was captured only in the Kwai Noi drainage in first to third order tributaries of three rivers, Pakkok, Khayeng, and U-Long, where it was generally uncommon. Garra fluviatilis was captured at only 15 of 54 sites sampled in these three rivers, and at only one was it relatively abundant with an average of one individual 1/ 6 m of stream length. Most sites where G. fluviatilis was captured (>75%) were shared with 12 other fishes: Devario regina (Fowler 1934) , Rasbora trilineata Steindachner 1870 , Barbodes binotatus (Valenciennes 1842) , Paracanthocobitis zonalternans (Blyth 1 860), Homalopteroides smithi (Hora 1932) , Schistura aurantiaca Plongsesthee, Page & Beamish 2011 , Schistura balteata (Rendahl 1948) , Batasio tigrinus Ng & Kottelat 2001 , Amblyceps variegatum Ng & Kottelat 2000 , Mastacembelus armatus (Lacepède 1800) , Rhinogobius sp., and Channa gachua (Hamilton 1822) . Another 36 species of fishes were variously present at some sites.

Garra fluviatilis was captured in riffles of smaller headwater tributaries (orders 1–3) at elevations between 200 and 250m where canopy cover was open to approximately 50%, and stream width was generally between 1.5–4 m ( Fig. 5 ). The upper substrata (10 cm) consisted almost entirely of gravel and larger particles (80–95% by weight). Water depth was mostly <30 cm. Water chemistry was measured at a number of sites on each river with the intention of characterizing ambient concentrations when fishes were sampled and, for Khayeng River, throughout the year. Chemical differences were found among sites, but no pattern was found in relation to the distribution or abundances of G. fluviatilis . In general, at locations where G. fluviatilis was sampled ambient oxygen was>90% of air saturation, ammonia was <0.08mg NH3N/l, pH was 7.9–8.3, and alkalinity was 70– 220mg CaCO3/l. Silica was high in all rivers where G. fluviatilis was captured with an approximate average of 20 mg /l, but varying between 8 and 30 mg /l.

Figures

FIGURE 1. Collection localities of Garra fluviatilis. The black star represents the type locality.

FIGURE 2. Holotype of Garra fluviatilis (NIFI 5083, 67.7 mm SL).

FIGURE 3. Mental disc and upper lip of Garra fluviatilis with rostral flap removed to expose unculiferous papillae on upper lip and pleated papilliferous fold at the junction of the lower jaw, anteromedial fold and anterolateral lobe (UF 1716452, 53.3 mm SL).

FIGURE 4. Garra fluviatilis, live specimen, Pakkok River, tributary to Vajiralongkorn Reservoir, Kwai Noi River drainage of the Mae Khlong basin at Ban Huay Khayeng, Thong Pha Phum District, Kanchanaburi Province, Thailand. (14 ° 40 ’ 51 ” N, 98 ° 31 ’ 13.3 ” E). Photo by Sakda Arbsuwan, 26 April 2011. Specimen deposited at National Inland Fisheries Institute (NIFI 5089, 52.75 mm SL).

FIGURE 5. Habitat of Garra fluviatilis. Pakkok River, tributary to Vajiralongkorn Reservoir, Kwai Noi River drainage of the Mae Khlong basin at Ban Huay Khayeng, Thong Pha Phum District, Kanchanaburi Province, Thailand. (14 ° 40 ’ 51 ” N, 98 ° 31 ’ 13.3 ” E). Photo by P. Kangrang, 26 April 2011.

Tables

TABLE 1. Morphometrics for Garra fluviatilis (N = 36) and for the holotype of G. s pil ota. Ranges and means include the holotype.

Morphometrics	Holotype	Range	Mean±SD	G. spilota holotype
Standard length (mm)	67.7	28.8–82.5	54.8±11.1	62.2
% of standard length:
Body depth	23.1	21.8–27.4	24.2±1.3	28.9
Head length	26.5	23.4–27.8	26.0±1.4	27.8
Body width at dorsal-fin origin	16.9	12.6–17.7	15.9±1.3	21.0
Body width at anal-fin origin	9.7	6.5–11.3	9.1±1.0	10.6
Caudal-peduncle width	4.4	3.8–5.4	4.6±0.4	5.7
Caudal-peduncle length	17.1	14.8–19.5	17.2±1.3	18.5
Caudal-peduncle height	12.6	12.0–13.9	13.1±0.5	12.5
1st branched dorsal-fin ray length	26.0	21.0–26.8	25.1±1.5	23.7
Dorsal-fin length	24.2	21.2–26.6	24.9±1.4	28.2
Dorsal-fin base length	13.5	11.0–16.3	14.2±1.4	16.1
Pectoral-fin length	23.2	23.8–27.2	25.6±0.9	22.3
Pelvic-fin length	21.7	19.1–23.5	22.2±1.1	20.6
Anal-fin length	19.4	18.4–23.1	20.4±1.1	19.3
Anal-fin base length	6.8	5.4–9.2	6.8±1.1	6.6
Upper caudal-fin lobe length	33.1	23.1–49.2	33.4±5.8	29.8
Lower caudal-fin lobe length	31.0	23.8–46.7	31.4±5.1	28.6
Medial caudal-fin ray length	18.9	14.7–33.5	20.1±3.6	19.5
Preanal-fin length	78.4	73.8–85.4	78.0±2.6	76.9
Preanus length	71.5	68.0–72.9	70.4±1.5	70.5
Prepelvic-fin length	51.8	49.5–55.1	52.5±1.5	54.5
Predorsal length	50.6	47.5–51.7	49.3±1.2	50.6
Prepectoral-fin length	23.6	21.2–26.6	23.3±1.2	25.2
Pelvic-anal length	26.2	23.6–29.8	26.4±1.7	22.2
% of pelvic-anal length:
Vent-anal length	29.2	23.4–36.9	28.9±3.5	26.5
% of head length:
Head depth	61.5	56.7–71.8	64.8±3.8	67.1
Head width	67.6	65.2–79.1	71.1±4.4	70.1
Snout length	46.8	39.5–50.9	45.5±3.3	49.3
Orbit diameter	20.1	19.7–28.6	23.1±2.0	20.9
Interorbital distance	45.9	38.7–52.0	44.6±3.3	47.4
Disc length	29.1	23.8–32.4	26.9±2.2	23.7
Disc width	43.7	33.3–46.8	40.1±3.4	36.9
Callous-pad length	13.8	11.3-17.0	13.7±1.6	11.3
Callous-pad width	21.3	19.1–26.9	22.9±2.4	20.2
Rostral-barbel length	14.5	13.1–18.3	15.1±1.4	12.6
Maxillary-barbel length	7.6	7.2–13.1	9.5±1.6	7.1