Laspionchis bourkei matangensis Dayrat & Goulding

Dayrat, Benoit, Goulding, Tricia C., Khalil, Munawar, Comendador, Joseph, Xuan, Qu ảng Ngo, Tan, Siong Kiat & Tan, Shau Hwai, 2019, A new genus of air-breathing marine slugs from South-East Asia (Gastropoda, Pulmonata, Onchidiidae), ZooKeys 877, pp. 31-80 : 64-68

Laspionchis bourkei matangensis Dayrat & Goulding ssp. nov. Figs 19E, F , 20A, B , 21C , 22C , 26 , 27 , 28 , 29

Holotype.

MALAYSIA • holotype, designated here, 15/9 mm [5958 H]; Peninsular Malaysia, Matang, facing fishermen’s village on the other side of river; 04°50.217'N, 100°36.826'E; 26 Jul. 2016; B Dayrat and party leg.; st 256, oldest and open Rhizophora forest of tall and beautiful trees, with hard mud, many creeks, and many old logs; USMMC 00055.

Additional material examined.

INDONESIA - Sumatra • 3 specimens 11/7 mm [1783], 10/7 mm [1784], 13/9 [1785]; Tembilahan; 00°10.243'S, 103°27.982'E; 13 Oct. 2012; M Khalil and party leg.; st 76, mangrove of large Avicennia trees, with old logs, soft but solid mud, and Nypa on the margin; UMIZ 00113. - Sulawesi • 1 specimen 12/10 mm [2230]; Bahoi; 01°43.355'N, 125°01.232'E; 12 Mar. 2013; M Khalil and party leg.; st 88, sand, small rocks, pieces of wood outside narrow coastal mangrove; UMIZ 00114. MALAYSIA - Peninsular Malaysia • 5 specimens 15/8 mm [5959], 12/9 mm [5960], 15/8 mm [5961], 13/8 mm [5963], 8/5 mm [5965]; same collection data as for the holotype; USMMC 00056. PHILIPPINES - Bohol • 1 specimen 25/18 mm [3343]; Mabini; 09°51.532'N, 124°31.685'E; 17 Jul. 2014; B Dayrat and party leg.; st 194, narrow mangrove on the edge of fish ponds, tall Rhizophora and Avicennia trees, many old logs; PNM 041254. • 1 specimen 10/7 mm [3616]; Inabanga; 10°00.389'N, 124°03.522'E; 12 Jul. 2014; B Dayrat and party leg.; st 186, old, rehabilitated fish ponds next to a mangrove with some old Avicennia but mostly young Rhizophora trees; PNM 041253. SINGAPORE • 3 specimens 9/7 mm [978], 9/8 mm [979], 10/8 mm [980]; Lim Chu Kang; 01°26.785'N, 103°42.531'E; 2 Apr. 2010; B Dayrat and party leg.; st 7, east of the jetty, open mangrove with medium trees, ending on mudflat outside mangrove with soft mud; ZRC.MOL.10485. • 2 specimens 13/8 mm [983], 10/7 mm [985]; Mandai River; 01°26.237'N, 103°45.730'E; 1 Apr. 2010; B Dayrat and party leg.; st 6, open mangrove forest with tall trees and soft mud, ending on mudflat outside the mangrove with very soft mud; ZRC.MOL.10484. VIETNAM • 2 specimens 8/4 mm [5627], 4/3 mm [5646]; Can Gio; 10°24.171'N, 106°53.960'E; 10 Jul. 2015; TC Goulding and party leg.; st 221, open Avicennia and Rhizophora mangrove with hard mud by a small road and deep mud near water; ITBZC IM 00018.

Distribution

( Fig. 7 ). Indonesia (Sulawesi, Sumatra), Malaysia (Peninsular Malaysia), Singapore, Philippines (Bohol), Vietnam.

Habitat

( Fig. 26 ). Same as the entire species Laspionchis bourkei (see above).

Etymology.

The subspecies L. bourkei matangensis is named after Matang, in Peninsular Malaysia. The type locality is part of the Matang mangrove forest. The name matangensis is an adjective derived from Matang and the suffix - ensis.

Diagnosis

(Table 3 ). Externally, the three subspecies of L. bourkei cannot be distinguished. Internally, L. bourkei matangensis differs from L. bourkei bourkei but cannot be distinguished from L. bourkei lateriensis . All three subspecies, however, are clearly delineated using molecular DNA sequences.

Color and morphology of live animals

( Fig. 27 ). Identical to the species L. bourkei (see above).

Digestive system

( Figs 19E, F , 20A, B ). Identical to the species L. bourkei (see above). Examples of radular formulae are in Table 4 . Radulae measure up to 2.2 mm in length.

Reproductive system

( Fig. 21C ). Identical to the species L. bourkei (see above).

Copulatory apparatus

( Figs 22C , 28 , 29 ). Similar to the species L. bourkei (see above) acknowledging some minor variations: the length of the spine of the accessory penial gland ranges from 0.4 mm [5958 H] (USMMC 00055) to 0.57 mm [3343] (PNM 041254), the retractor muscle is vestigial or absent, and penial hooks measure 15 to 40 μm.

Remarks.

See above the remarks on the species Laspionchis bourkei .

Figures

Figure 7. Geographical distribution of the two species of Laspionchis. Distinct colors are used for each subspecies of L. bourkei. The colors used are the same as those used in the phylogenetic trees (Figs 2 - 5). Colored areas correspond to hypothetical geographical ranges based on known records.

Figure 19. Digestive system, dorsal view, Laspionchis bourkei A-C L. bourkei bourkei, Australia, Northern Territory D Holotype, L. bourkei lateriensis, Indonesia, Ambon E, F L. bourkei matangensis, Peninsular Malaysia. A [1673] (NTM P. 57618) B [1666] (NTM P. 57618) C [1693] (NTM P. 57619) D [6064 H] (UMIZ 00115) E [5959] (USMMC 00056) F holotype, [5958 H] (USMMC 00055). Scale bars: 2 mm (A, C-E), 2.5 mm (B), 1 mm (F). Abbreviations: ddg dorsal digestive gland i intestine pdg posterior digestive gland r rectum st stomach.

Figure 20. Radula, Laspionchis bourkei A, B L. bourkei matangensis, Peninsular Malaysia [5965] (USMMC 00056) C-F Holotype, L. bourkei bourkei, Australia, Northern Territory [1657 H] (NTM P. 57615). A Rachidian and innermost lateral teeth B lateral teeth C rachidian and lateral teeth D rachidian and innermost lateral teeth E lateral teeth F outermost lateral teeth. Scale bars: 10 μm (A, D, F), 30 μm (B), 100 μm (C), 80 μm (E).

Figure 21. Posterior, hermaphroditic (female) reproductive system, Laspionchis bourkei. A Holotype, L. bourkei bourkei, Australia, Northern Territory, [1657 H] (NTM P. 57615) B holotype, L. bourkei lateriensis, Indonesia, Ambon, [6064 H] (UMIZ 00115) C holotype, L. bourkei matangensis, Peninsular Malaysia, [5958 H] (USMMC 00055). Scale bars: 2 mm (A), 1 mm (B, C). Abbreviations: dd deferent duct fgm female gland mass hg hermaphroditic gland ov oviduct rs receptaculum seminis sp spermatheca.

Figure 22. Anterior, male, copulatory apparatus, Laspionchis bourkei. A Holotype, L. bourkei bourkei, Australia, Northern Territory, [1657 H] (NTM P. 57615) B holotype, L. bourkei lateriensis, Indonesia, Ambon, [6064 H] (UMIZ 00115) C holotype, L. bourkei matangensis, Peninsular Malaysia, [5958 H] (USMMC 00055). Scale bars: 1 mm (A), 2 mm (B), 0.5 mm (C). Abbreviations: ag accessory penial gland dd deferent duct ms muscular sac ps penial sheath rm retractor muscle v vestibule.

Figure 26. Habitats, Laspionchis bourkei matangensis. A, B Peninsular Malaysia, Matang, old and open Rhizophora forest of with hard and soft mud, many creeks, and many old logs (st 256, type locality) C Singapore, mud outside mangrove on sun-exposed mudflat (st 7) D Philippines, narrow mangrove on the edge of fish ponds, tall Rhizophora and Avicennia trees, many old logs (st 194) E Indonesia, Sumatra, soft but solid mud, big Avicennia, a few logs, some Nypa on margin, little open space (st 76) F Vietnam, open Avicennia and Rhizophora mangrove with hard mud by a small road and deep mud near water (st 221).

Figure 27. Live specimens, Laspionchis bourkei matangensis. A Dorsal view, 13 mm long [1785], Indonesia, Sumatra (UMIZ 00113) B dorsal view, 10 mm long [1784], Indonesia, Sumatra (UMIZ 00113) C dorsal view, 11 mm long [1783], Indonesia, Sumatra (UMIZ 00113) D dorsal view, 15 mm long [5961], Peninsular Malaysia, Matang (USMMC 00056) E dorsal view, 25 mm long [3343], Philippines, Bohol (PNM 041254) F holotype, dorsal view, 15 mm long [5958 H], Peninsular Malaysia, Matang (USMMC 00055) G ventral view, 13 mm long [5963], Peninsular Malaysia, Matang (USMMC 00056) H ventral view, 8 mm long [5965], Peninsular Malaysia, Matang (USMMC 00056) I ventral view, same as E.

Figure 28. Penial hooks, Laspionchis bourkei matangensis, Peninsular Malaysia A, B Holotype [5958 H] (USMMC 00055) C-E [5959] (USMMC 00056) F [5960] (USMMC 00056). Scale bars: 10 μm (A, C), 3 μm (B), 4 μm (D), 5 μm (E), 20 μm (F).

Figure 29. Spine of the accessory penial gland, Laspionchis bourkei matangensis. A Holotype, Peninsular Malaysia, [5958 H] (USMMC 00055) B Peninsular Malaysia, [5959] (USMMC 00056) C Philippines, [3343] (PNM 041254) D Peninsular Malaysia, [5960] (USMMC 00056) E same as A F same as B. Scale bars: 100 μm (A-C), 50 μm (D), 5 μm (E, F).