Macrobrachium neglectum (De Man, 1905)

Cai, Y., Naiyanetr, P. & Ng, P. K. L., 2004, The freshwater prawns of the genus Macrobrachium Bate, 1868, of Thailand (Crustacea: Decapoda: Palaemonidae), Journal of Natural History 38 (5), pp. 581-649 : 590-591

Macrobrachium neglectum (De Man, 1905)

Palaemon acutirostris De Man, 1888: 280 , pl. 18; figure 7 (not Dana, 1852).

Palaemon (Eupalaemon) neglectus De Man, 1905: 201 , pl. 15: figure 6 [type locality: Mergui Archipelago and north-eastern Sumatra].

Macrobrachium neglectus: Suvatti, 1937: 49 ; 1967: 140.

Macrcrochium javanicum: Holthuis, 1950: 190 (part); 1980: 94 (part); Chace and Bruce, 1993: 29 (part); Tiwari, 1955b: 232.

Macrobrachium javanicum neglectum: Johnson, 1960: 262 , figure 2.

Macrobrachium neglectum: Ng and Choy, 1990: 15 ; Cai and Ng, in press.

Material examined

East Thailand. Ten specimens (CU 1997.192), Trat, 7 April 1976 .

Southern Thailand. Two ovigerous XX, cl 24–25 mm ( ZRC 2000.2716 ), Narathiwat Province, Ban Sac tributary of Sungai Kolok, ca 19.5 km westward towards Waeng at T-junction from Sungai Kolok to Waeng and Sungai Padi , 5°47.49∞N, 101°80∞E, pH 7.6, coll H. H. Tan et al., 23 October 1998 ; 2 WW, cl 13.5–21.5 mm, 25 ovigerous XX, cl 10–17.5 mm ( ZRC 2000.2628 ), Ranong Province: Kapoe District: Klong Ban Man waterfall, along highway 4 milestone 22 km to Kapoe , 9°27∞24.2◊N, 98°30∞31.1◊E, coll. D. C. J. Yeo et al., 12 August 1997 ; 1 W, cl 25 mm, 1 X, cl 16 mm ( ZRC 2000.2702 ), Nam Tok Tone Sai , Phuket, 8°01.64∞N, 98°21.74∞E, pH 7.8, coll. P. K. L. Ng and H. H. Tan, 8 April 1999 ; 2 XX, cl 10.5–16.0 mm ( ZRC 2000.2631 ), Ranong Province, Khlong Phrae Sai at Ban Kreo Noi , km 8 on road branching east 32 km north of Ranong on road Ranong Kra Buri, coll. M. Kottelat, 6 November 1995 ; 1 W, cl 8.8 mm, 2 XX, cl 9.6–10.2 mm, Narathiwat Province, stream on Phu Khao Thong, 6 km west of Ban Bu Ke Ta , pH 6.5, coll. 2 November 1995 ; 2 WW, cl 14.6–21.2 mm, 1 ovigerous X, eggs 0.7× 0.5 mm ( ZRC 2000.2633 ), Ranong Province, stream north of Khura Buri , 100 km south of Ranong, pH 5.9, coll. M. Kottelat, 5 November 1995 ; 4 WW, cl 10.0– 13.5 mm, 1 X, cl 8.2 mm ( ZRC 2000.2634 ), Narathiwat Province, strem at bridge about 1 km south of bridge on Mae Nam road Tod Deng , about 5 km north of Narathiwat, coll. M. Kottelat, 3 November 1995 ; 3 WW, cl 9.8–10.3 mm, 1 ovigerous X, cl 13.2 mm ( ZRC 2000.2627 ) Ranong Province, King Amphoe Suk Sam Lan: Ton Koi waterfall, 9°20∞14.6◊N, 98°27∞18.9◊E, coll. D. Yeo et al., 11 August 1997 ; 14 WW, cl 10.8–18.3 mm ( ZRC 2000.2627 ), Ranong Province, King Amphoe Suk Sam Lan, Ton Koi waterfall, 9°20∞14.6◊N, 98°27∞18.9◊E, coll. D. Yeo et al., 11 August 1997 ; 3 WW, cl 13.4–21.5 mm, Ranong, coll. Priyawut, 28 January 1986 ; 1 W, cl 8.5 mm (CU 1997.23), Bang Pat waterfall, Thalang Phuket, 14 October 1986 ; 1 W, cl 31.0 mm (CU 1997.39), river Thap Put , Phang Nga, 24 August 1986 ; 2 WW, cl 12.0–13.0 mm (CU 1997.40), Tao Hong waterfall, Thap Put, Phang Nga, 27 March 1987 ; 3 WW, cl 16.0–20.0 mm, 3 XX, cl 15.0 mm (CU 1997.41), Ban Pai waterfall, Thalang , Phuket, 1986; 1 X, cl 18.0 mm (CU 1997.42), Lumru waterfall, Kapong, 11 September 1986 ; 9 WW, cl 18.5–30.0 mm, 2 XX, cl 18.5 mm (CU 1997.43), Lumru waterfall, Kapong, 11 September 1986; 7 WW, cl 15.0–22.0 mm, 2 XX, cl 17.0– 18.5mm (CU 1997.44), Ban Pai waterfall, Thalang, 8 May 1987; seven specimens, cl 9.0–16.0 mm (CU 1997.45), Tao Thong , Thap Put, 11 December 1986; three specimens , cl 14.0–20.0 mm (CU 1997.46), Lum Pee waterfall, Thai Muang , Phang Nga, 31 August 1987; 24 specimens , cl 11.0– 22.5 mm (CU 1997.47), Bang Pa waterfall, Thalang, 8 May 1987 ; 2 WW, cl 25.0 mm, 4 ovigerous XX, cl 18.0–19.0 mm (CU 1997.48), Thai Muang, 8 August 1987; nine specimens, cl 8.0–12.0 mm (CU 1997.49), Bang Pa waterfall, Thalang, 8 May 1987 ; 4 WW, cl 23.0– 29.5 mm (CU 1997.50), Takua Pa , 28 August 1986; 20 specimens (CU 1997.51) , Ton Sai waterfall, Thalang , 8 May 1987; 33 specimens (CU 1997.52) , Lum Pee waterfall, Thai Muang , 20 April 1986 ; 4 WW, cl 24.0–28.0 mm, 3 XX, cl 14.0–17.0 mm (CU 1997.54), Bam Drik waterfall, Thai Muang, 25 July 1986; 4 WW, cl 16.0–32.0 mm, 2 XX, cl 11.5–16.0 mm, 30 other specimens, Lum Ru waterfall, Kapong, 11 September 1987; 19 specimens, cl 8.0–14.0 mm (CU 1997.56), Bang Pa waterfall, Thalang, 29 March 1986 ; 1 W, cl 30.0 mm (CU 1997.57), Ton Sai waterfall, Thalang, 6 July 1986 ; 1 W, cl 31.0 mm (CU 1997.58), Tao Thong Water , Thap Put, 20 July 1986 ; 1 W, cl 31.0 mm (CU 1997.59), Phang Nga, 20 July 1986 ; 11 WW, cl 15.0–29.0 mm, 7 XX, cl 11.0–16.0 mm (CU 1997.60), Ton Na Nua waterfall, Thai Muang, 8 May 1987 ; 3 WW, cl 25.5–31.0 mm (CU 1997.61), Tone Na Nua waterfall, Phang Nga, 25 August 1986 ; 3 WW, cl 16.0–17.0 mm, 40 other specimens (CU 1997.62), Patong waterfall, Phuket, 21 June 1986; eight specimens , Kanim waterfall, Phang Nga, 9 December 1980 ; 2 WW, cl 14–22 mm, 1 X, cl 17 mm (CU 1997.89), Ranong, coll. Priyawut, 28 January 1986; two specimens (CU) , Pun Sak Tan , Nakhon Si Thammarat, October 1976 .

Thai specimens with no specific locality. Twenty-one specimens (CU 1997.66); one specimen (CU 1997.68); 19 specimens (CU 1997.69); 13 specimens (CU 1997.78); 2 WW, cl 29.0–30.0 mm (CU 1997-63).

Remarks

De Man (1888) reported Palaemon acutirostris from Mergui. Subsequently, he (De Man, 1905) reassigned these specimens, together with some Sumatran ones to a new species, P. (Eupalaemon) neglectus . Holthuis (1950), however, thought this taxon was identical with M. javanicum (Heller, 1862) . Johnson (1960) highlighted the differences between these two species, and considered them as two separate subspecies, M. javanicum javanicum and M. javanicum neglectum . Naiyanetr (1980), Ng and Choy (1990), and recently Cai and Ng (in press) treated both as good species.

This species seems to prefer streams with fast running waters or waterfalls. In Thailand, M. neglectum had previously been reported from Koh Chang by Suvatti (1937).