Corresponding author: B.A.R. Azman (
Academic editor: Alan Myers
Eleven taxa including one new species of gammaridean amphipods are reported from the waters of Pulau Tioman. The presence of
According to
Particular efforts in conducting more regional based studies should be emphasized to further advance the biodiversity knowledge of these numerically abundant and taxonomically diverse taxa. Hence, the result of this work should in addition to documenting the amphipod fauna, provide new insights into the diversity and distribution patterns of the South China Sea amphipods.
Located 2°35’ north of the equator and in the South China Sea, Pulau Tioman (
In the framework of research on taxonomic revision and ecology of selected families of gammaridean amphipods conducted at Pulau Tioman, several qualitative benthic samples from different habitats and substrate types have been analysed. In some of these samples, specimens of gammaridean amphipods were found, one of which belongs to new species herein described, and for those species already known, the morphology of populations from Pulau Tioman are compared with other populations described in the literature. Due to the high importance of Pulau Tioman to maintain inventories for scientific marine studies in the Marine Protected Areas of Malaysia, we consider it important to include these species in this report, together with the description of the new taxa.
The material for the present study came from the following locations in the waters of Pulau Tioman, Pahang (
Study area with localities of sampling stations.
Whole animals were transferred into glycerol and drawn with a camera lucida on an Olympus SZX9 dissecting microscope. The specimens were dissected and appendages and mouthparts mounted onto slides in glycerol and drawn under a Leica DMLB light microscope using a camera lucida. Types have been deposited at Universiti Kebangsaan Malaysia Muzium Zoologi Australian Museum, Sydney , antenna , abdomen , epimeron , gnathopod , head , left , lower lip , lacinia mobilis , mandible , maxilla , maxilliped , pereopod , pleopod , pleonite , right , telson , uropod , upper lip , male , female
5 specimens, TIO-15, Renggis, Pulau Tioman,
Taking into consideration that
5 specimens, TIO-12, Kampung Tekek, Pulau Tioman, 2
The specimens seem referable to the
3 specimens, TIO 10, Kampung Tekek, Pulau Tioman, 2
The well-developed sharp spur on the peduncle of uropod 1 distinguishes the present specimens from the genera
The Pulau Tioman specimens also appear to be very close to
In all probability, this material from Pulau Tioman is very similar to Imbach’s illustrations in having; (1) article 2 of mandibular palp three fourths as long as article 3; (2) maxilliped extends beyond palp article 2; (3) accessory flagellum with 1 articulate; (4) article 5 shorter than article 6 of gnathopod 1; (5) rami of uropod 3 two thirds as long as peduncle; (6) peduncle of uropod 1 with strong, acute, distoventral interramal process; (7) uropod 2 with short triangular interramal process.
24 specimens, TIO 10, Kampung Tekek, Pulau Tioman, 2
The Malaysian specimens differ from those described from the waters of Japan only by the lack of the accessory setae of the mandible. At present, this seems inadequate for subspecific distinction due to the enormous resemblance of other characters shared between them. Even though
2 specimens, TIO 5, Monkey Bay, Pulau Tioman, 2
The Pulau Tioman specimens agree well with figures of
4 specimens, TIO 28, Tulai, Pulau Tioman,
Referred to many times in the literature from Thailand, this is the first record of
2 specimens, TIO 34, Tomok, Pulau Tioman,
The Pulau Tioman material accords well with the description and figures of
3 specimens, TIO 28, Tulai, Pulau Tioman,
10 specimens, TIO 3, Monkey Bay, Pulau Tioman, 2
The Pulau Tioman specimens closely resemble
5 specimens, TIO 12, Kampung Tekek, Pulau Tioman, 2
Recently
The Pulau Tioman specimens undoubtedly represent the tropical members (
Although the Pulau Tioman specimens are more closely related to
Nevertheless the specimens at hand are apparently very close to
Holotype, male, body length 4.5 mm (from tip of rostrum to apex of telson) (Ref: UKMMZ-1252).
Marine Park, Pulau Tioman, (
32 specimens, TIO 22, Marine Park, Pulau Tioman,
Rostrum long and linguiform. Accessory flagellum absent. Maxilla 1, palp article 2 stout armed with several short teeth apically. Maxilla 2, outer plate broader than inner plate, both with plumose setae along margin. Lower lip lacking inner lobes. Mandible palp article 2 long. Gnathopod 2 lacking carpal lobe, more slender articles of carpus and propodus. Pereopods 3-4 with pair of stout locking spines. Telson cleft, lacking large spines on apices.
Male: 4.5 mm. Head, rostrum large, long, curved down, apically blunt, lateral cephalic lobe broad, shallow, quadriform, defined below by weak but sharp incision; antero-ventral margin bulbous, rounded. Eye large, occupying more than half of head area.
Antenna 1 only about 70 percent as long as antenna 2; flagellum with about 21-articulate, ornamented with aesthetascs ventrally; accessory flagellum absent. Antenna 2 about half as long as body; gland cone of peduncular article 2 broad, extending beyond of peduncle article 3; flagellum long and thin with about 28 articles.
Mandible, molar triturative, each with ragged seta; lacinia mobilis serrate and clearly distinct; palp with article 2 about twice as broad as article 3, latter slightly falcate. Lower lip lacking inner lobes, mandibular lobes subtruncate and apically fringed with small setae. Maxilliped inner plate with apicolateral spine separated from 2 medioapical spines by gap and hollow; outer plate with facial setules in 1 row and a few scattered; palp article 2 broad. Maxilla 1, palp article 2 stout armed with several short teeth apically. Maxilla 2, outer plate broader than inner plate, both with plumose setae along margin.
Gnathopod 1-2 small, subequal in size to each other, basis scarcely setose posteroventrally; propodus long, thin, sub-rectangular, palm evenly oblique.
Gnathopod 1 carpus sub-triangular, posterior margin short, lobe extended; dactylus not serrate on grasping margin. Gnathopod 2 similar to gnathopod 1. Pereopods 1-7 elongate. Pereopods 3-4 homopodous; merus slightly expanded posterodistally; carpus about ½ the length of propodus. Pereopods 5-7 homopodous; basis expanded roundly. Pereopod 7 similar but longer than pereopod 6; basis more elongate than pereopod 6.
Uropod 1 peduncle spinose on lateral margin, almost 2 times as long as outer ramus, one medium sized robust seta at distal part; outer ramus about 0.7 times as long as inner ramus, apex bifid, armed with several apical spines, one elongate. Uropod 2 extending beyond telson; peduncle subequal in length to inner ramus, spinose, and with one long robust seta at distal end; outer ramus almost 0.6 times as long as inner ramus with several apical robust setae; inner ramus apically bifid with several robust setae along margin. Uropod 3 peduncle short; rami foliaceous, subequal in length, marginally spinose and setose. Telsonflat, broad, cleft more than halfway, apices slightly rounded, broad, smooth, lateral margins of lobes with 2 pairs of partial sets of fine short setae.
The specific designation is derived from the name of the Sunda shelf, which was part of the south-east Asian continent during the Pleistocene.
Checklist of the recorded amphipods.
|
|
|
---|---|---|
1. |
||
2. |
||
3. |
||
4. |
||
5. |
||
6. |
||
7. |
||
8. |
||
9. |
||
10. |
||
11. |
We are grateful to Zuhaimi Samat, Shamsul Bahar, Jenifer Jusi Josim, Kee Alfian, Rayida Jaraeh, Tomoko Okashita and Takeshi Maekawa who assisted in the field sampling. This work was supported by a grant (UKM-ST-08-FRGS0020-2009) from the Ministry of Higher Education of Malaysia and a UKM research grant (DIP-2012-020). Thanks are also due to the Marine Park Section, Department of Fisheries, Malaysia.