Macrobrachium dacqueti ( Sunier, 1925 )

Wowor, Daisy & Ng, Peter K. L., 2007, The Giant Freshwater Prawns Of The Macrobrachium Rosenbergii Species Group (Crustacea: Decapoda: Caridea: Palaemonidae), Raffles Bulletin of Zoology 55 (2), pp. 321-336 : 326-328

Macrobrachium dacqueti ( Sunier, 1925)

( Figs. 4 , 5B–C , 6 , 7B , 9 , 10 )

Cancer (Astacus) carcinus – Herbst, 1792: 58, Pl. 28, Fig. 1 (not Cancer carcinus Linnaeus, 1758 ).

Astacus carcinus – Fabricius, 1793: 479 (part) (not Cancer carcinus Linnaeus, 1758 ).

Palaemon carcinus – Fabricius, 1798: 402 (part); Olivier, 1811: 659; von Martens, 1868: 34 (part); de Man, 1879: 165 (part); 1888: 280; 1897: 766; 1908: 224, Pl. 19, Fig. 5 ; Miers, 1880: 382 (part); Ortmann, 1891: 700, Pl. 47, Fig. 1 ; Henderson, 1893: 340, 441; Lanchester, 1901: 565; Henderson & Matthai, 1910: 281, Pl. 15, Fig. 1 a-g; Kemp, 1918: 255; Menon, 1938: 292, Figs. 21-23; Tiwari, 1955: 232 (not Cancer carcinus Linnaeus, 1758 ).

Palemon carcinus – H. Milne Edwards, 1837: 395 (not Cancer carcinus Linnaeus, 1758 ).

Palaemon (Eupalaemon) carcinus – de Man, 1892: 421 (part); 1898: 137; 1902: 475, 763 (part); Nobili, 1900: 480; Roux, 1932: 564, 568; Boone, 1935: 154, Pl. 39 (not Cancer carcinus Linnaeus, 1758 ).

Palaemon whitei (Guérin-Meneville MS) Sharp, 1893: 122 (nomen nudum).

Palaemon d’Acqueti Sunier, 1925: 117 .

Macrobrachium carcinus – Suvatti, 1937: 49 (not Cancer carcinus Linnaeus, 1758 ).

Macrobrachium rosenbergii – Holthuis, 1950: 111, Fig. 25 (part); 1959: 67, 98; Johnson, 1960: 261 (part); 1961: 56; Ling & Merican, 1961: 55; Sandifer & Smith, 1979: 56; Tombes & Foster, 1979: 179; Hedgecock et al., 1979: 873 (part); Lindenfelser, 1984: 195 (part); Hiramatsu et al., 1985: 150; Liu et al., 1990: 104; Ng, 1990: 197; 1994: 75; 1997: 269; Ng & Choy, 1990: 15; Choy, 1991: 126, 138, Pl. 9; Barki et al., 1991a: 252; 1991b: 145; 1997: 81; Naiyanetr, 1998: 33; Dang & Ho, 2001: 33, Fig. 12; Mather & de Bruyn, 2003: 4 (part); de Bruyn et al., 2004: 251 (part); Wowor et al., 2004: 346, Fig. 8 ; de Bruyn et al., 2005: 370 (not Palaemon rosenbergii de Man, 1879 ).

Macrobrachium rosembergii (sic) – Maccagno & Cucchiari, 1957: 355, Fig. 44 (not Palaemon rosenbergii de Man, 1879 ).

Macrobrachium rosenbergii schenkeli Johnson, 1973: 277 .

Macrobrachium rosenbergii dacqueti – Holthuis, 1995: 148; 2000: 16, Fig. 2.1 ; Beekman, 1999: 18, Pl. 1 Fig.B, 396; Cai & Dai, 1999: 233; Wowor & Choy, 2001: 286; Cai & Ng, 2002: 78; Cai et al., 2004: 582 .

Material examined. – Type material: Palaemon d’Acqueti Sunier, 1925 : lectotype, male (74.1 mm CL, designated herein) ( RMNH D 1065 ), Batavia [Jakarta], Java, Indonesia, coll. P. Bleeker , 1842- 1860; paralectotypes, 2 ovigerous females (34.4–38.6 mm CL) ( RMNH D 2437 ), Kampung Makassar near Batavia [Jakarta], Java, Indonesia, coll. S. F. Groen , 1861.

Other material. – Indonesia: Java : 3 females (13.3–30.0 mm CL) ( MZB Cru.1319), Cibinua R., Banten ; 3 males (44.2-86.4 mm CL) ( MZB), Cikawung R., Banjar; Sumatra : 7 males (48.9–56.7), 10 females (17.9–47.6 mm CL) ( USNM 67553 ), Musi R., Palembang ; 1 male (33.9 mm CL), 1 female (36.4 mm CL) ( MZB Cru.1064), Krueng Jambo, Aceh ; 3 males (52.9–70.3 mm CL), 4 ovigerous females (41.9–48.7 mm CL) ( ZRC 2000.2408 ), Batam Is.; Kalimantan : 2 males (19.5–23.5 mm CL), 3 females (20.4–26.1 mm CL), 3 ovigerous females (24.8–27.0 mm CL) ( MZB Cru. 1423 & 1424), Lake Jempang ; 3 males (28.9–88.9 mm CL) ( MZB), Lake Semayang ; 13 males (53.0–65.0 mm CL), 1 female (27.1 mm CL), 3 ovigerous females (30.8–42.6 mm CL) ( ZRC 2000.2406 ), Tayan R .; 2 males (67.3–67.4 mm CL), 2 ovigerous females (36.6–45.3 mm CL) ( ZRC 2000.2405 ), Sambas R .; 5 males (61.3–75.4 mm CL), 1 female (34.5 mm CL) ( MZB), Sambas R.; 1 ovigerous female (34.0 mm CL) ( ZRC 1995.462 ), Sebuku R .; 3 males (19.9–21.7 mm CL), 1 female (35.2 mm CL) ( ZRC 1995.526 ), Tulit R., Semunad ; 1 male (23.3 mm CL) ( ZRC 2000.2401 ), Kapuas R. at Sintang ; 7 males (11.7–14.8 mm CL), 3 females (11.7–13.0 mm CL) ( MZB), Kapuas R. at Sintang . Brunei Darussalam: 2 males (69.2–80.9 mm CL), 2 ovigerous females (40.5–44.9 mm CL) ( ZRC 1996.1682 – 1685 ), Bandar Seri Begawan . Cambodia: 3 males (70.6–74.7 mm CL) ( ZRC), Tonle Sap . Singapore: 2 males (53.2–53.4 mm CL) ( ZRC) ; 2 males (30.5–41.5 mm CL) ( ZRC 1986.258 – 259 ), Nee Soon near Seletar Reservoir . Malaysia: Peninsular Malaysia: 1 male (56.5 mm CL), 1 ovigerous female (40.0 mm CL) ( ZRC 2000.2402 ), Selangor R.; 2 males (26.8–53.6 mm CL) ( NHM 1893.24 ), Pinang Is.; 3 males (36.2–52.6 mm CL), 1 female (34.1 mm CL) ( ZRC), Taman Negara, Pahang ; 2 males (32.5–41.9 mm CL), 1 female (31.3 mm CL) ( ZRC), Tahan R. in Taman Negara, Pahang ; 4 males (41.2–42.2 mm CL) ( ZRC 1996.113 – 116 ), Tanjung Kualang, Ipoh ; 4 males (20.45–47.55 mm CL) ( ZRC), Ulu Sedili R., Mawai, Johor ; East Malaysia : 1 female (35.8 mm CL) ( NHM 1900.12.1.34), Kuching ; 2 females (32.7–34.0 mm CL) ( NHM), Kuching Bay ; 1 male (59.6 mm CL), 1 female (24.4 mm CL) ( NHM 1893.3.26.1–2), Marabah ; 2 males (57.2–69.7 mm CL), 1 female (46.5 mm CL) ( ZRC 2000.2404 ), Serian ; 2 males (62.8–75.5 mm CL), 1 ovigerous female (41.6 mm CL) ( ZRC 1996.1686 – 1688 ), Serian ; 1 male (47.9 mm CL) ( ZRC 2000.2403 ), Nyungan R. in Lanjak-Entimau Wildlife Sanctuary ; 1 male (54.6 mm CL), 2 ovigerous females (29.3–36.5 mm CL) ( MZB), Kinabatangan R. at Bukit Garam ; 1 male (49.4 mm CL), 1 female (33.3 mm CL) ( ZRC 1994.4200 ), Kinabatangan R. near Batu Puteh ; 2 males (24.7–32.4 mm CL) ( ZRC 1994.4218 ), Kinabatangan R. near Batu Puteh ; 1 female (32.4 mm CL) ( ZRC 1994.4209 ), Kinabatangan R. at jetty to Danau Girang ; 3 males (31.6–42.4 mm CL), 1 ovigerous female (41.6 mm CL) ( ZRC 2000.2478 ), Marudu R . Thailand: 1 male (86.7 mm CL) ( USNM), Thailand ; 1 male (66.0 mm CL) ( USNM 21365 ), Trang ; 1 male (54.7 mm CL) ( USNM), Trang ; 1 male (65.6 mm CL) ( USNM), Chao Phraya R .; 1 male (24.1 mm CL) ( USNM 65563 ), Chao Phraya R .; 1 male (65.6 mm CL) ( USNM 95528 ), Chao Phraya R .; 1 male (20.4 mm CL) ( USNM 65564 ), Chao Phraya R. at Pak Nam ; 2 males (14.6–15.3 mm CL) ( USNM 65565 ), Bangkok ; 1 female (19.0 mm CL) ( USNM 65494 ), Bangkok ; 2 males (16.5–18.7 mm CL), 5 females (18.1–21.5 mm CL) ( USNM), Mae Khlong R. at Ratchaburi ; 1 male (32.9 mm CL) ( USNM 65491 ), Pasak R .; 1 female (28.4 mm CL) ( USNM 65490 ), Chao Jet R. at Ban Pua ; 1 male (19.6 mm CL), 1 female (15.4 mm CL) ( USNM 65492 ), river at Pak Kret ; 2 males (16.5–18.7 mm), 1 female (12.4 mm CL) ( USNM 65493 ), Ranode R., outlet of a lake . Myanmar (= Burma): 1 male (68.4 mm CL) ( NHM 1889.6.17.139), Tavoy ; 1 female (33.4 mm CL) ( NHM 1889.6.17.180), Tavoy ; 3 males (48.4–63.9 mm CL) ( NHM 1891.11.20.1–4), Tungoo . Sri Lanka: 1 male (67.2 mm CL) ( NHM), Ceylon ; 1 female (33.4 mm CL) ( USNM), Mahaweli R. at Trincomalee .

Diagnosis. – Rostrum: Long (1.17–1.44 times CL in young males of 24.70–28.85 mm times CL with tip distinctly extending beyond distal end of scaphocerite), becoming relatively shorter with age (0.76–1.01 CL in fully adult males of 65 mm CL and larger with tip slightly extending beyond or reaching distal end of scaphocerite); moderately deep, maximum depth slightly more than maximum dorsoventral diameter of cornea; basal crest high to moderately high, sinuous; teeth above orbit closely spaced, teeth on distal two-thirds of rostrum widely spread, armed with 8–15 teeth (mode 13) including 1 apical tooth, 2 or 3 teeth completely postorbital, postorbital teeth on anterior 0.25–0.28 of carapace; ventral carina with 6–16 teeth (mode 12), first tooth located at about proximal one-fifth or one-fourth.

General cephalon: ocular cornea well developed, 0.09–0.10 times CL (0.11–0.14 times CL in other specimens). Carapace spinulate. Ocular beak well developed with expanded lateral tip. Epistome completely bilobed, lobes with blunt rounded margin.

Second pereiopod: distal half of merus extend beyond end of scaphocerite. Cheliped: large spines abundant on all segments except dactylus; dactylus thickly covered by pubescence; chela 2.08–2.20 times CL, length 12.06–14.01 times width, outer and inner margins straight; palm subcylindrical, about equal to maximum merus width, width 0.94–1.02 times depth, outer and upper margins more densely covered with smaller spines than inner and lower margins; fingers 0.67–0.76 times palm length, not gaping; dactylus with 2 large teeth on proximal one-third, subequally distributed, pollex with 1 large tooth at distal and 2 smaller teeth towards articulation of fingers distributed along proximal 0.26, teeth unequally distributed along cutting edges; carpus 0.94–0.99 times palm length, subcylindrical, length 6.33–8.02 times distal width, 1.31–1.38 times merus length; merus straight, 1.29–1.38 times ischium length; ischium tapered.

Third pereiopods: medium-sized spines present on all segments; distal half of propodus extends beyond scaphocerite; dactylus stout, curved, ventral carina obsolete; propodus length 17.05–19.71 times longer than wide.

Thoracic sternum: T4 with small triangular median process, without posterior submedian plate; T8 with moderately separated anterolateral lobes, without median process. Abdomen: smooth, glabrous. Male abdominal sternites: first 2 abdominal sternites each with medium-sized triangular median process, third abdominal sternite without median process. Inter-uropodal sclerite: well developed as longitudinal preanal carina, carina small or medium-sized. Telson: moderate, stout, glabrous.

Remarks. – The first published figure of this species appeared in Rumphius (1705, D’Amboinsche Rariteikamer, Pl. 1 Fig. B) under the name of “ Locusta Marina ”, but there is no text accompanying the figure. The original figure of Rumphius’ Rariteitkamer is still extant and was republished by Beekman (1999: 18, Fig. 1B ) and Holthuis (2000: 14, Fig. 2.1 ). The high basal crest of the rostrum of the original figure of the prawn makes it likely that this is Macrobrachium dacqueti which is in Rumphius Memorial Volume and was considered as M. rosenbergii (see Holthuis, 1959: 67).

Herbst (1792) was the first to provide a good description and illustration of M. dacqueti under the name Cancer (Astacus) carcinus Linnaeus, 1758 . However, Fabricius in his accounts of Astacus carcinus (in 1793) and Palaemon carcinus (in 1798) referred only to Rumphius’ Pl. 1, Fig. B. Subsequently, Fabricius (1798) transferred the Linnaean species from Astacus to Palaemon . The specific name Palaemon carcinus ( Fabricius, 1798) was then adopted (incorrectly) for the next 150 years until the matter was clarified by Holthuis (1950). Interestingly, the work of Herbst was overlooked by Fabricius and subsequent workers had in fact used the name P. carcinus (also incorrectly) for the East Indian form. The real Macrobrachium carcinus ( Linnaeus, 1758) , as pointed out by Holthuis (1950), is a wholly American species.

Holthuis (2000: 13), who provided a taxonomic history of the last 200 years of this species, comments: “The first who challenged this nomenclature was Sunier (1925), who showed that Linnaeus’ description of Cancer carcinus was solely based on material of the American species named jamaicensis by Herbst (1792). Sunier (1925) accepted the consequences of his discovery and replaced the name jamaicensis by carcinus and proposed the new specific name dacqueti for the Indo- West Pacific species, honoring burgomaster d’Acquet. In 1950, Sunier’s views were confirmed ( Holthuis, 1950), except that he pointed out that the name Palaemon rosenbergii de Man, 1879 for the Indo-West Pacific species is older than P. dacqueti Sunier, 1925 , and that the specific name rosenbergii had to be used for the present species”.

Johnson (1973 a) first recognized the differences between the two taxa, but he treated them as subspecies, including establishing a new name for the western population which he named M. rosenbergii schenkeli . This recognition of two subspecies was followed by Hedgecock et al. (1979), Lindenfelser (1984) and de Bruyn et al. (2004). Holthuis (1995) provided the correct nomenclature for the two subspecies, and he correctly noted that the western subspecies must be known as M. r. dacqueti ( Sunier, 1925) , if this population be recognized as a separate taxon. In the present study, M. r. dacqueti is regarded as a distinct species, i.e. M. dacqueti .

Distribution. – Asian mainland to the western border of Huxley’s Line excluding Palawan, i.e. from eastern part of Pakistan, India, Sri Lanka, and southern China up to Borneo and Java.

Figures

Fig. 4.Macrobrachium dacqueti (Sunier, 1925):A, ovigerous female 41.90 mm CL, lateral view (ZRC 2000.2408); B, male 64.15 mm CL, close up, carpus of second pereiopod (SAM C 11228).

Fig. 5. Carapace: A, Macrobrachium rosenbergii (male 75.0 mm CL, Ajkwa R., Papua, Indonesia, not preserved); B–C, M. dacqueti: B, adult (male 62.60 mm CL, Jaya R., Bukit Sarang area, Bintulu, Sarawak, East Malaysia, Borneo, coll. H. H. Tan (ZRC), 20 Aug.2005; C, young specimen from Serian, Sarawak, East Malaysia, Borneo, not preserved.

Fig. 6. Young individuals: A–B, Macrobrachium rosenbergii: A, 45.0 mm CL, Tambulig, Panguil Bay, Mindanao, Philippines, not preserved; B, Ajkwa R., Papua, Indonesia, not preserved; C, M. dacqueti, Serian, Sarawak, East Malaysia, Borneo, not preserved.

Fig. 7. Abdomen: A, Macrobrachium rosenbergii (male 75.0 mm CL,Ajkwa R., Papua, Indonesia, not preserved); B, Macrobrachium dacqueti (male 62.80 mm CL, Mahakam R., Melak, E. Kalimantan, Indonesia).

Fig. 9. Macrobrachium dacqueti: A, male 62.60 mm CL, Jaya R., Bukit Sarang area, Bintulu, Sarawak, East Malaysia, Borneo, coll. H. H. Tan (ZRC), 20 Aug.2005; B, male 88.90 mm CL, Lake Semayang, E. Kalimantan, Indonesia, coll. D. Wowor & H. H. Tan (MZB), Nov.1999; C, male 62.80 mm CL, Mahakam R., Melak, E. Kalimantan, Indonesia); D, 2 males, from aquaculture, Philippines, originating from Thailand, not preserved.

Fig. 10. Map of natural distribution of Macrobrachium rosenbergii (on the right side of dash line) and M. dacqueti (on the left side of dash line). Dashed line = distribution border of the two species.

Fig. 1. Scatterplot of MDA scores (first root) for the two supposed subspecies, adults only. Symbols: Macrobrachium rosenbergii rosenbergii females (filled circle), M. r. rosenbergii males (empty circle), M. r. dacqueti females (filled square) and M. r. dacqueti males (empty square). Eigenvalue = 28.709; Wilks’s λ = 0.034; χ2 = 200.095, df = 8, p <0.0001.

Fig. 8. Macrobrachium rosenbergii:A, B, 2 adult males from Ajkwa R., Papua, Indonesia, not preserved; C, 2 ovigerous females from Dinas, the Philippines, not preserved.

Fig. 2. Scatterplot of MDA scores (first root) for the two supposed subspecies, males only. Symbols: Macrobrachium rosenbergii rosenbergii adult males (filled circle), M. r.rosenbergii young males (empty circle), M. r. dacqueti adult males (filled square) and M. r. dacqueti young males (empty square). Eigenvalue = 6.587; Wilks’s λ = 0.132; χ2 = 267.485, df = 8, p <0.0001.