Paralaubuca harmandi Sauvage, 1883

(Figures 1, 5, 10)

Paralaubuca Harmandi Sauvage, 1883:153 .

Type locality: Thailand: Mé-Nam (Chao Phraya). Holotype: MNHN A-6427.

Culter siamensis Hora, 1923:149, pl. 10 fig. 1, pl. 11 figs. 4–5.

Type locality: Thailand: Bangkok. Holotype: ZSI F 10504 /1.

Culter wolfi Fowler, 1937:163, fig. 101.

Type locality: Thailand: Pitsanulok. Holotype: ANSP 68016 .

Paralaubuca harmandi was described by Sauvage in 1883 based on a single specimen (Figure 10A) from the Chao Phraya River, Thailand having 7 branched dorsal-fin rays, 24 branched anal-fin rays, and 75 lateral-line scales. Bănărescu (1971) examined the holotype and noted it measured 147 mm SL.

Culter siamensis was described by Hora (1923) based on a single specimen measuring 175 mm SL (Figure 10B) from Bangkok, with 9 (=7 branched) dorsal-fin rays, 24 branched anal-fin rays, 13 pectoral-fin rays, and 75 lateral-line scales. Hora (1923) also gave a count of 7 pelvic-fin rays, which perhaps was an error or based on an aberrant specimen, given the otherwise consistent count of 9 pelvic-fin rays in Paralaubuca . We agree with Bănărescu (1971) that C. siamensis is a synonym of P. harmandi .

Culter wolfi was described by Fowler (1937) from the Chao Phraya basin at Pitsanulok, Thailand. The holotype (Figure 10C) measured 205 mm TL, and four paratypes measured 123–185 mm TL. The five specimens had 7 branched dorsal-fin rays, 14 pectoral-fin rays, 9 pelvic-fin rays, and 22–23 branched anal-fin rays. The lateral-line scale count was given as “23 to 25 (overlap 5 to 10, and sometimes auxiliary median series of 8 scales may be interposed) + 53 to 55 + 7 to 9 in lateral line.” We interpret this to mean lateral-line scales in a single row would number at least 73 and possibly as many as 84. Fowler noted C. wolfi was similar to C. siamensis but differed in having the pectoral fins longer than the head. Bănărescu (1971) examined the holotype and paratypes of C. wolfi, which he considered a synonym of P. harmandi, and other specimens he assigned to P. harmandi to describe the species as having 7 branched dorsal-fin rays, 21–25 branched anal-fin rays, 70–86 lateral-line scales, and 26–33 rakers on the first gill arch. We found the holotype has 80 and paratypes have 73–80 lateral-line scales and agree with Bănărescu (1971) that C. wolfi is a synonym of P. harmandi .

Diagnosis. Paralaubuca harmandi is distinguished from P. typus and P. barroni by having 70–87 vs. 68 or fewer lateral-line scales, usually 22–24 vs. 24–29 branched anal-fin rays, 26–33 (usually 28–32) vs. 20–28 (usually 26 or fewer) scales around caudal peduncle, and total vertebral counts of 41–42 (average=41.9, n=9) vs. 38–41 (average=39.3, n=21) in P. typus; and 38–41 (average=39.9, n=7) in P. barroni . Paralaubuca harmandi has shorter anal fin and anal-fin base, and smaller eye than P. typus and P. barroni (Table 9). It is further differentiated from P. typus by having 29–33 vs. 31–51 rakers on first gill arch. Paralaubuca harmandi is distinguished from P. typus and P. barroni osteologically as described above and as shown in Figure 5. Reaching 265 mm SL, P. harmandi is much larger than both P. typus and P. barroni, which reach 152.5 and 115.0 mm SL, respectively.

Description. See description of genus.

Distribution. Paralaubuca harmandi is known from the Chao Phraya and Mae Klong River basins of Thailand, and the Mekong River basin of Cambodia and Thailand (Figure 8B). Observations and collections of the species have been in flowing water in moderate to large rivers. Paralaubuca harmandi occurs syntopically with P. typus, both species having been collected at six of the 13 localities documented for P. harmandi .

Based on specimens in institutional collections, P. harmandi is known to be widespread in the Chao Phraya basin, occurring as far north as the Ping River in Chiang Mai Province and south to Bangkok, but appears to be relatively uncommon. In the Mae Klong River basin, it was recorded in Kanchanaburi Province in 1963 (Johnsen 1963) and in Ratchaburi Province (UMMZ 195277) in 1964. The species may have been extirpated from the Mae Klong basin, perhaps because of the massive dams on the mainstem and on each of its primary tributaries, the Khwae Noi and Khwae Yai.

Several publications have implied P. harmandi is widespread in the Mekong River basin, but the only verified records known to us are from two localities, the Mun River near Ubon Ratchathani, Thailand (NIFI 00068, UF 249816, UMMZ 195744), and Prek Andor, Cambodia (MNHN-IC-1983-0170). Bănărescu (1971) indicated the distribution of P. harmandi as Menam [= Chao Phraya] and Mekong drainages in Thailand, but all specimens listed by him were from the Chao Phraya basin. Taki (1974) did not include P. harmandi among the four names he used for species of Paralaubuca from Laos. Rainboth (1996) mentioned P. harmandi as being in the lower Mekong but provided no locality records and included a drawing of Culter siamensis from Hora (1923), who described C. siamensis from Bangkok, drained by the Chao Phraya River. Kottelat (2001) reported P. harmandi from the Mekong of Cambodia, Laos, and Thailand, but provided no locality records, and the photo on page 67 purported to be of P. harmandi is a photo of P. typus or P. barroni . So et al. (2019) did not include P. harmandi in a field guide to fishes of Cambodia. Rainboth et al. (2012) included a photo of P. harmandi in a photographic atlas of fishes of the Mekong, but the specimen in the photo was noted as having been from Chainat, Thailand on the Chao Phraya River. Vidthayanon (2008) described the distribution of P. harmandi as middle to lower Mekong and Chao Phraya basins and included the same photo as that in Rainboth et al. (2012) from the Chao Phraya River. Panitvong (2022) reported P. harmandi from the Chao Phraya and Mekong River basins and included a photo of P. harmandi from Phitsanulok (personal communication) on the Chao Phraya River. Taki et al. (2021) noted that no specimens conforming to P. harmandi were found in the Mekong River basin in surveys spanning seven years. Paralaubuca harmandi has not been collected in the Mekong River basin since the 1960s and may be extirpated from the basin. If gone from the Mae Klong and Mekong River basins, the species occurs now only in the Chao Phraya River basin.

Paralaubuca harmandi:

Chao Phraya River basin: Thailand: Ang Thong Province: UF 193674, 1, 53.6, Chao Phraya R., Pa Mok, 14.45141, 100.45999, Tangjitjaroen, W., 11 Feb 2014 . Ayutthaya Province: UF 248526, 7 of 11, 120.5–143.0, Chao Phraya R., 14.17823, 100.5019, Tangjitjaroen, W., 21 Jun 2022; UF 249416, 2, 79.3 – 86.6, Chao Phraya R. at Bang Sai fishing house, 14.17823, 100.50190, Tangjitjaroen, W., 18 Nov 2022 . Bangkok Province: USNM 108123, 1, 115.2, canal of Hugh M. Smith's yard in Bangkok, 13.76221, 100.49180 (est.), Smith, H. M., 8 Sep 1934 ; USNM 108135, 1, 160, Chao Phraya R., Bangsorn, 13.76221, 100.49180 (est.), Smith, H. M., 12 Sep 1923 . Bangkok [now Samut Prakan] Province: ANSP 60800, 2 of 3, 158.0–178.1, Chao Phraya R., 13.70562, 100.56186, Deschauensee, R. M., 1936 ; ANSP 89441, 3 of 7, 100.3–136.2, Chao Phraya R., 13.70562, 100.56186, Deschauensee, R. M., 1936 . Chiang Mai Province: UF 248506, 1, 183.2, Maesoi Dam on Ping R., 18.2681, 98.6417, Tangjitjaroen, W., 31 Oct 2021 . Chainat Province: NIFI 02433, 2, 203.0–233.0, Chao Phraya R., 15.16195, 100.18802, Vidthayanon, C., 21 Jan 1992; UF 249816, 2, 112.5 – 133.9, Chao Phraya R., 15.16195, 100.18802, Grudpan, C., no date . Nakhon Sawan Province: UF 173084, 2, 136.6 – 168.9, market in Nakhon Sawan, from Bung Boraphet, 15.72675, 100.16885, Page, L. M. and Tangjitjaroen, W., 17 June 2008 ; UF 248898, 1, 236, Chao Phraya R. Phayuha Khiri, 15.453487, 100.134564, Randall, Z., et al., 9 Jun 2022 ; UMMZ 195097, 1, X-ray, Chao Phraya R., 15.69975, 99.96032, Lagler, K. F., 15 Oct 1964 . Phitsanulok Province: ANSP 68016, holotype of Culter wolfi, 168.4, Nan R., 16.82357, 100.26064, Deschauensee, R. M., 1936 ; ANSP 68017–68020, 3 of 4 paratypes of Culter wolfi, 131.4–153.4, Nan R., 16.82357, 100.26064, Deschauensee, R. M., 1936 ; NIFI 04600 –A, 2, 70.4–97.4, Bang Kaeo canal, 16.81285, 100.13272 (est.), Suksri, S., 20 Oct 2010 . Sukothai Province: ANSP 212133, 1, 52.3, Mae Poon (or Mae Phun), small tributary of Yom R., 17.66667, 99.7 (est.), Deschauensee, R. M., 1936 . Tak Province: UMMZ 195117, 1, 265, Bhumiphol Reservoir, ca. 2 km from Yanhee Dam, 17.24021, 98.98963, Lagler, K. F., 15 Oct. 1964 . Unknown province: BMNH 1898.4.2.244-245, 2, X-rays, Me Nam River [Chao Phraya] .

Mae Klong River basin: Thailand: Ratchaburi Province: UMMZ 195277, 2, 109.9 – 128.2, market at Ratchaburi., 13.54110, 99.82483, Lagler, K. F. and Thiemed, J., 14 Nov 1964 .

Mekong River basin: Cambodia: Phnom Penh Province: MNHN-IC-1983-0170, 1, 185 mm, Prek Andor, 11.65919, 104.86086 (est.), Nov 1961 . Thailand: Ubon Ratchathani Province: NIFI 00068, 4, 108.9 –156.0, Mun R., 15.30859, 105.49353 (est.), Tiancharoen, P., 13 Jan 1968; UMMZ 195744, 1, X-ray, Mun River, ca. 5 km downstream from Ubon, 15.23343, 104.93410, Lagler, K. F., et al., 11 Feb 1965 .