Pontodrilus litoralis (Grube, 1855)

(Figures 2, 3, 7B; Tables 2, 3)

Lumbricus litoralis Grube, 1855: 127 –129, pl. 5, figs 5–10.

Pontoscolex arenicola Schmarda, 1861: 11 –12, pl. 18, fig. 157.

Pontodrilus marionis Perrier, 1874: 1582 –1586. Perrier 1881: 176 –179, pls 13–17, pl. 18; figs 40–43.

Pontodrilus bermudensis Beddard, 1891: 96 . Michaelsen 1894: 183 –184. Beddard 1895: 469 –471. Michaelsen 1910: 84 –89. Michaelsen 1913: 417. Michaelsen 1921: 12. Stephenson 1923: 180 –182. Gates 1926: 150. Stephenson 1931: 51. Gates 1942: 90. Gates 1943: 99 –100. Gates 1954: 240 –241. Gates 1972: 47 –48. Jamieson & Wampler 1979: 665 –666. Sathianarayanan & Khan 2006: 139 –144.

Cryptodrilus insularis Rosa, 1891: 387 –388, pl. 14, fig. 11.

Pontodrilus arenae Michaelsen, 1892: 222 –223, pl. 13, fig. 9. Michaelsen 1900: 181. Michaelsen 1903: 87.

Pontodrilus hesperidum Beddard, 1894: 37 –40. Beddard 1895: 471. Michaelsen 1900: 182. Michaelsen 1903: 87.

Pontodrilus litoralis (Grube) . Beddard 1895: 469. Michaelsen 1900: 180. Cognetti 1901: 16. Michaelsen 1903: 87. Michaelsen 1910: 89 –91. Easton 1984: 114 –116. Jamieson 2001: 1002 –1007, figs 34.1–34.2. Gobi et al. 2004: 1712, fig. 1. James et al. 2005: 1022 –1023. Shen et al. 2005: 12 –13, fig. 1. Blakemore 2007: S3–S8, figs 1–3. Csuzdi & Pavlicek 2009: 12. Satheeshkumar et al. 2011: 406 –409, fig. 1. Blakemore et al. 2012: 302. Narayanan et al. 2014: 473 –476, table 1. Oba et al. 2015: 1 –10, figs 1–2, table 1. Hara et al. 2016: 5 –7, fig. 1. Nguyen et al. 2016: 10 –11.

Pontodrilus insularis (Rosa) . Beddard 1895: 471 –472. Michaelsen 1897: 173 –174. Michaelsen 1900: 181 –182. Michaelsen 1903: 87.

Pontodrilus michaelseni Eisen, 1895: 73 –84, pl. 33, figs 24–28; pls 34–39; pl. 40, figs 74–76. Michaelsen 1900: 182. Michaelsen 1903: 87.

Pontodrilus ephippiger Rosa, 1898: 281 –283, pl. 9, figs 4–5. Michaelsen 1900: 180 –181. Michaelsen 1903: 87. Michaelsen 1907a: 187. Michaelsen 1907b: 43. Cognetti 1908: 81 –82. Stephenson 1914: 256 –259.

Pontodrilus matsushimensis Iizuka, 1898: 21 –26, pl. 2, figs 1–6. Beddard 1899: 192 –193. Michaelsen 1900: 179 –180. Michaelsen 1903: 87. Michaelsen 1910: 91 –92. Easton 1981: 45 –46.

Pontodrilus ephippiger laysanianus Michaelsen, 1899a: 217 –220. Michaelsen 1899b: 28 –29, fig. 2. Michaelsen 1900: 181.

Pontodrilus matsushimensis chathamianus Michaelsen, 1899a: 220 –221. Michaelsen 1900: 180. Michaelsen 1910: 91 –92.

Pontodrilus michaelseni hortensis Eisen, 1900: 241 –243.

Pontodrilus chathamensis (sic! pro chatamianus) Michaelsen. Benham 1901: 136 –140. Lee 1952: 25.

Pontodrilus chathamianus Michaelsen. Michaelsen 1903: 87 .

Pontodrilus laccadivensis Beddard, 1903: 374 –375.

Pontodrilus crosslandi Beddard, 1906: 561, fig. 78.

Pontodrilus albanyensis Michaelsen, 1907a: 185 –187, fig. 12, pl. 2, fig. 26. Jackson 1931: 93.

Pontodrilus bermudensis ephippiger Rosa. Stephenson 1915a: 145 . Stephenson 1915b: 61. Stephenson 1916: 311. Stephenson 1917: 375. Stephenson 1920: 202. Jackson 1931: 95 –96, pl. 14, fig. 6.

Pontodrilus albanyensis var. cygni Jackson, 1931: 94 –95, pl. 14, figs 2, 3, 4, 9.

Plutellus (Pontodrilus) matsushimensis indica Michaelsen, 1935: 106 –107.

Pontodrilus gracilis Gates, 1943: 100 –102. Gates 1954: 241.

Pontodrilus hesperidium (sic! pro hesperidum) Beddard. Easton 1984: 114. Jamieson 2001: 1003.

Type locality. Villa Franca on the French Riviera (Grube 1855).

Materials examined. Thailand. 112 adults and 51 juveniles, CUMZ 3462, Ao Talkoo, Laem Ngob, Trat (12° 12' 14.4" N, 102° 16' 47.1" E) on 7 August 2015 . 21 adults and 56 juveniles, CUMZ 3463, Hat Laem Sing, Laem Sing, Chanthaburi (12° 28' 48.5" N, 102° 03' 46.7" E) on 7 August 2015 . 8 adults and 14 juveniles, CUMZ 3464, Hat Chao Lao, Thamai, Chanthaburi (12° 33' 52.8" N, 101° 54' 25.1" E) on 8 August 2015 . 38 adults and 48 juveniles, CUMZ 3465, Hat Mae Rumphueng, Ban Phe, Rayong (12° 36' 12.6" N, 101° 23' 52.2" E) on 8 August 2015 . 38 adults and 8 juveniles, CUMZ 3466, Hat Nam Rin, Ban Chang, Rayong (12° 40' 31.1" N, 101° 05' 03.4" E) on 9 August 2015 . 26 adults and 49 juveniles, CUMZ 3467, Ao Noi, Mueang, Prachuap Khiri Khan (11° 49' 10.7" N, 99° 47' 58.1" E) on 29 August 2015 . 53 adults and 34 juveniles, CUMZ 3468, Maejo University at Chumphon, Lamae, Chumphon (9° 46' 48.8" N, 99° 08' 27.2" E) on 29 August 2015 . 1 adult and 7 juveniles, CUMZ 3469, Hat Pak Meng, Sikao, Trang (7° 30' 14.3" N, 99° 19' 6.8" E) on 30 August 2015 . 89 adults and 30 juveniles, CUMZ 3470, Ao Noon, La Ngu, Satun (6° 50' 16.0 "N, 99° 45' 37.2" E) on 30 August 2015 . 131 juveniles, CUMZ 3471, Khrua Suan Son Restaurant, Pak Phanang, Nakhon Si Thammarat (8° 10' 51.8" N, 100° 17' 30.4" E) on 1 September 2015 . 1 adult and 18 juveniles, CUMZ 3472, Ban Koh Kaew Naruemit, Pak Phanang, Nakhon Si Thammarat (8° 14' 28.1" N, 100° 16' 41.2" E) on 3 September 2015 . 1 adult and 29 juveniles, CUMZ 3473, Laem Talumphuk, Pak Phanang, Nakhon Si Thammarat (8° 19' 19.7" N, 100° 15' 19.9" E) on 3 September 2015 . 7 adults and 60 juveniles, CUMZ 3474, Pak Mae Nam Tepa, Sichon, Nakhon Si Thammarat (8° 55' 51.2" N, 99° 54' 47.5" E) on 3 September 2015 . 45 juveniles, CUMZ 3475, Klong Bang Siap, Patiew, Chumphon (10° 39' 29.9" N, 99° 18' 39.1" E) on 4 September 2015 . 16 adults and 23 juveniles, CUMZ 3476, Hat Nang Kam, Don Sak, Surat Thani (9° 18' 53.7" N, 99° 45' 37.9" E) on 2 December 2015 . 170 adults and 32 juveniles, CUMZ 3477, Hat Lamai, Koh Samui, Surat Thani (9° 28' 16.3" N, 100° 03' 10.3" E) on 3 December 2015 . 42 adults and 16 juveniles, CUMZ 3478, Koh Samui Hospital, Koh Samui, Surat Thani (9° 31' 17.3" N, 99° 56' 08.5" E) on 3 December 2015 . 24 adults and 9 juveniles, CUMZ 3479, Hat Sai Ngoen, Klong Yai, Trat (12° 02' 43.5" N, 102° 45' 01.8" E) on 15 December 2015 . 16 adults and 36 juveniles, CUMZ 3480, Hat Ban Chuen, Klong Yai, Trat (11° 52' 56.9" N, 102° 47' 58.7" E) on 15 December 2015 . 41 adults and 1 juvenile, CUMZ 3481, Wat Huang Som, Klong Yai, Trat (11° 50' 47.4" N, 102° 49' 31.9" E) on 15 December 2015 . 86 adults and 29 juveniles, CUMZ 3482, Lung Chalerm Bungalow Koh Chang, Koh Chang, Trat (12° 05' 52.4" N, 102° 21' 27.9" E) on 16 December 2015 . 81 adults and 39 juveniles, CUMZ 3483, Laem Sing, Laem Sing, Chanthaburi (12° 30' 59.0" N, 102° 01' 37.7" E) on 17 December 2015 . 25 adults and 13 juveniles, CUMZ 3484, Laem Mae Nok Kaew, Na Yai Arm, Chanthaburi (12° 40' 46.7" N, 101° 48' 41.2" E) on 17 December 2015 . 38 adults and 5 juveniles, CUMZ 3485, Wat Tanon Kaprao, Klaeng, Rayong (12° 41' 06.1" N, 101° 40' 27.2" E) on 17 December 2015 . 6 adults and 6 juveniles, CUMZ 3486, Laem Mae Pim, Klaeng, Rayong (12° 38' 37.6" N, 101° 38' 05.1" E) on 17 December 2015 . 23 adults and 4 juveniles, CUMZ 3487, Ao Dong Tai, Sattahip, Chonburi (12° 38' 46.6" N, 100° 55' 47.4" E) on 18 December 2015 . 80 adults and 19 juveniles, CUMZ 3488, Hat Jomtien, Pattaya, Chonburi (12° 50' 25.1" N, 100° 54' 18.3" E) on 18 December 2015 . 42 adults and 6 juveniles, CUMZ 3489, Hat Na Klua, Pattaya, Chonburi (12° 58' 08.0" N, 100° 54' 04.4" E) on 18 December 2015 . 53 adults and 5 juveniles, CUMZ 3490, Hat Bang Saen, Mueang, Chonburi (13° 15' 10.9" N, 100° 55' 45.4" E) on 18 December 2015 . 28 adults and 21 juveniles, CUMZ 3491, Bo Nok, Kui Buri, Prachuap Khiri Khan (11° 59' 47.8" N, 99° 51' 50.2" E) on 9 January 2016 . 22 adults and 7 juveniles, CUMZ 3492, Hat Sang Arun, Tub Sakae, Prachuap Khiri Khan (11° 34' 10.9" N, 99° 39' 48.7" E) on 9 January 2016 . 34 adults and 28 juveniles, CUMZ 3493, Ban Ma Phaw Resort, Bang Saphan Noi, Prachuap Khiri Khan (11° 08' 08.1" N, 99° 29' 11.9" E) on 9 January 2016 . 10 adults and 5 juveniles, CUMZ 3494, Hat Koey, Kaper, Ranong (9° 37' 26.7" N, 98° 28' 08.6" E) on 10 January 2016 . 16 adults, CUMZ 3495, Hat Manee Naka, Kaper, Ranong (9° 28' 40.4" N, 98° 26' 02.8" E) on 10 January 2016 . 2 adults, CUMZ 3496, Wat Tet Tum Nava, Thai Muang, Phangnga (8° 21' 21.9" N, 98° 15' 29.9" E) on 10 January 2016 . 36 adults and 4 juveniles, CUMZ 3623, Ao Thalen, Mueang, Krabi (8° 09' 58.0" N, 98° 44' 53.0" E) on 11 January 2016 . 8 juveniles, CUMZ 3624, Hat Yao, Nuea Klong, Krabi (7° 58' 49.4" N, 98° 56' 46.6" E) on 11 January 2016 . 10 juveniles, CUMZ 3625, Hat Samran, Hat Samran, Trang (7° 14' 02.9" N, 99° 32' 19.4" E) on 12 January 2016 . 52 adults and 30 juveniles, CUMZ 3626, Hat Bo Chet Look, La Ngu, Satun (6° 53' 32.6" N, 99° 41' 12.5" E) on 12 January 2016 . 20 adults and 10 juveniles, CUMZ 3627, Hat Kao Seng, Mueang, Songkhla (7° 10' 58.9" N, 100° 36' 59.5" E) on 12 January 2016 . 17 adults and 3 juveniles, CUMZ 3628, Hat Tumbon Kao Roob Chang, Mueang, Songkhla (7° 09' 06.5" N, 100° 38' 25.0" E) on 12 January 2016 . 1 adult and 61 juveniles, CUMZ 3629, Hat Na Tub, Jana, Songkhla (7° 04' 26.3" N, 100° 41' 34.6" E) on 12 January 2016 . 19 adults and 51 juveniles, CUMZ 3630, Hat Sai Kaew, Singha Nakhon, Songkhla (7° 15' 13.1" N, 100° 32' 53.1" E) on 13 January 2016 . 2 adults and 1 juvenile, CUMZ 3631, Hat Ma Ha Rat, Satingpra, Songkhla (7° 28' 10.1" N, 100° 26' 50.1" E) on 13 January 2016 . 40 adults and 12 juveniles, CUMZ 3632, Wat Hua Rawa, Ranod, Songkhla (7° 43' 30.3" N, 100° 22' 55.4" E) on 13 January 2016 . 1 adult, CUMZ 3633, Klong Loe, Tha Sala, Nakhon Si Thammarat (8° 45' 02.0" N, 99° 56' 13.4" E) on 14 January 2016 . 119 adults and 81 juveniles, CUMZ 3634, Klong Klai, Tha Sala, Nakhon Si Thammarat (8° 46' 36.1" N, 99° 56' 06.4" E) on 14 January 2016 . 67 adults and 11 juveniles, CUMZ 3635, Laem Sai, Chaiya, Surat Thani (9° 25' 26.2" N, 99° 17' 05.5" E) on 14 January 2016 . 49 adults and 26 juveniles, CUMZ 3636, Klong Pak Nam Thamueng, Tha Chana, Surat Thani (9° 33' 15.9" N, 99° 12' 39.2" E) on 14 January 2016 . 63 adults and 22 juveniles, CUMZ 3637, Hat Sam Roi Yot, Sam Roi Yot, Prachuap Khiri Khan (12° 16' 50.6" N, 99° 58' 23.8" E) on 15 January 2016 . 50 adults and 93 juveniles, CUMZ 3638, Hat Cha-am, Cha-am, Phetchaburi (12° 49' 36.2" N, 99° 59' 40.3" E) on 15 January 2016 .

Malaysia. 5 adults and 54 juveniles, CUMZ 3639, Tanjung Rhu, Sepang, Selangor (2° 38' 07.2" N, 101° 37' 26.8" E) on 21 January 2016 . 154 adults and 62 juveniles, CUMZ 3640, Jalan Klebang, Besar Dataran1, Melaka (2° 13' 13.7" N, 102° 11' 09.3" E) on 22 January 2016 . 71 adults and 85 juveniles, CUMZ 3641, Tanjung Kling, Pantai Kundur, Melaka (2° 14' 54.9" N, 102° 08' 15.3" E) on 22 January 2016 . 64 adults and 148 juveniles, CUMZ 3642, Kampung Pasir Putih, Pasir Gudang, Johor (1° 26' 16.8" N, 103° 55' 32.9" E) on 23 January 2016 . 149 adults and 65 juveniles, CUMZ 3643, Highway Senai Desaru, Sungai Johor, Johor (1° 32' 02.6" N, 104° 01' 47.8" E) on 23 January 2016 . 102 adults and 57 juveniles, CUMZ 3644, Tanjung Balau, Desaru, Johor (1° 36' 55.8" N, 104° 15' 26.1" E) on 23 January 2016 . 59 adults and 22 juveniles, CUMZ 3645, Sungai Jemaluang, Mersing, Johor (2° 23' 03.5" N, 103° 52' 40.8" E) on 23 January 2016 . 95 adults and 96 juveniles, CUMZ 3646, Kampung Air Puteri, Mersing, Johor (2° 24' 56.0" N, 103° 51' 32.5" E) on 24 January 2016 . 33 adults and 42 juveniles, CUMZ 3647, Kampung Janglau, Pantai Kuala Rompin, Pahang (2° 43' 17.2" N, 103° 34' 24.9" E) on 24 January 2016 . 20 juveniles, CUMZ 3648, Kampung Pandon, Pekan, Pahang (3° 05' 40.8" N, 103° 26' 26.2" E) on 24 January 2016 . 83 adults and 10 juveniles, CUMZ 3649, Kampung Tanjung Lumpur, Kuantan, Pahang (3° 48' 25.0" N, 103° 20' 29.4" E) on 25 January 2016 . 38 adults and 46 juveniles, CUMZ 3650, Pantai Chendor, Cukai, Terengganu (4° 10' 36.7" N, 103° 25' 15.6" E) on 25 January 2016 . 16 adults and 7 juveniles, CUMZ 3651, Teluk Bidara, Sungai Dungun, Dungun, Terengganu (4° 47' 03.9" N, 103° 25' 39.0" E) on 25 January 2016 . 79 adults and 22 juveniles, CUMZ 3652, Kampung Batin Seberang Takir, Kuala Terengganu, Terengganu (5° 20' 42.7" N, 103° 07' 40.7" E) on 26 January 2016 . 52 adults and 4 juveniles, CUMZ 3653, Sungai Besut Kampung Nail, Besut, Terengganu (5° 49' 25.5" N, 102° 33' 24.7" E) on 26 January 2016 . 82 adults and 26 juveniles, CUMZ 3654, Pantai Melawi, Sungai Ger Bachok, Kelantan (5° 59' 35.7" N, 102° 25' 54.2" E) on 26 January 2016 . 49 adults and 27 juveniles, CUMZ 3655, Tanjung Dawai, Merbok, Kedah (5° 40' 47.4" N, 100° 22' 12.8" E) on 28 January 2016 . 107 adults and 46 juveniles, CUMZ 3656, Tanjung Bungah, Pulau Pinang (5° 28' 06.7" N, 100° 16' 41.0" E) on 28 January 2016 .

Description of new material. Length 28–136 mm, diameter 1–5 mm, body cylindrical, 76–128 segments. Body colour red to pink, pale brown around clitellum (newly collected specimens after placement in 30% (v/v) ethanol for narcotization). Prostomium epilobous. Clitellum saddle in XIII–XVII or XVIII, setae present. Setae lumbricine, ab absent on XVIII, aa> bc, ab <cd, aa> cd, dd> aa. Female pores paired in setal line b on XIV. Male pores minute and superficial on XVIII, close to sites of b setae, penial setae absent (or not found). Spermathecal pores minute, intersegmental, two pairs in 7/8 and 8/9, ventrolateral, in line with setae b. Dorsal pores totally absent. Genital markings large, medio-ventral, transversely oval across 19/20 (some in 20/21), center depressed.

Septa 5/6–12/13 thickened. Gizzard and calciferous glands absent. Intestine beginning in XVI or XVII. Intestinal typhlosole absent. Esophageal hearts seen in VI–XIII. Nephridia absent in the anterior segments and begin in XIII or XV with a pair of coiled tubules, smaller after clitellum. Spermathecae two pairs in VIII and IX, spermathecal diverticula slender, narrower at the junction with ampulla. Tubular prostate single pair, muscular duct curved and narrowed at each end, coil in XVIII. Ovaries present in XIII. Testes funnels in X and XI, seminal vesicles paired and large in XI–XII. Accessory glands absent.

Distribution. Worldwide, sub-tropical and tropical coastal areas. Easton (1984) and Blakemore (2002) provide distribution records; Figure 1 shows the locations of our finds of the species in Thailand and Peninsular Malaysia.

Habitat. Sandy beaches at the intertidal zone, mangrove swamps, coastal salt marsh of estuaries and brackish water. Found in the top soil to 20 cm depth where the salinity ranges from 1–33 ppt.

Remarks. Pontodrilus litoralis shows some variations in body dimensions, patterns of the genital markings, and shape of the spermathecal diverticula, especially if the descriptions of the many junior synonyms and redescriptions of the nominal species are taken into account. Characters from synonyms of P. litoralis in the Old World territory, including Australia, are presented in Table 2. Variations in body dimensions were reported by Jamieson (2001), Satheeshkumar et al. (2011), Shen et al. (2005) and Narayanan et al. (2014); the values are as follows: Jamieson (2001): length 32–120 mm, width 2–4 mm, segments 78–120; Satheeshkumar et al. (2011) and Narayanan et al. (2014): length 50–130 mm, clitellum width 2–4 mm, segments 81–115; Shen et al. (2005): length 50–130 mm, diameter 1–2 mm, segments 81–115. Considering genital markings, Jamieson (2001) notes the following variations, based on specimens from Peel Island, and including data of Jackson (1931), Gates (1972) and Easton (1984): genital markings in several furrows of 11/12–20/21. Specimens described by Jamieson (2001) from Nornalup, Western Australia, have markings at 17/18, at the anterior midventral margin of XVIII, at 18/19, or midventral at 18/19 and 19/20. Satheeshkumar et al. 2011; Narayanan et al. 2014 observed large genital markings medio-ventral at 19/ 20 in specimens from India; specimens of P. litoralis from coasts of the Penghu Island and the southwestern Taiwan have one large genital marking, transversely oval across 19/20, center depressed (Shen et al. 2005). Considering the diverticulum, Jamieson (2001) described it as digitiform to club-shaped, whereas in specimens from India and Taiwan it is slender. The specimens of P. litoralis investigated in this study are within the variation range as reported in the literature: body length 28–136 mm, diameter 1–5 mm, segments 76–128; genital markings large, medio-ventral, transversely oval across 19/20 (some in 20/21). We include drawings (Fig. 2) and colour plates (Fig. 3) of selected specimens.