Sample checklist of Gastropoda and Bivalvia in Cham Islands, Vietnam

The researchers involved in this project were Dr. Do Van Tu (sample collection, taxonomic identification, data management), Dr. Le Hung Anh (sample collection) and Dr. Tran Anh Tuan (map drawing) from the Institute of Ecology and Biological Resources and Dr. Luu The Anh (sample collection) from theInstitute of Geography. Both institutes are under the Vietnam Academy of Science and Technology. Moreover, Dr. Takenori Sasaki from the University Museum, The University of Tokyo, helped to verify the identification of all species.

Cham Archipelago consists of one large island surrounded by seven small islands covering a sea area of 15 square kilometres and it is located in Central Vietnam, 16 kilometres from the coast and 19 kilometres to the east of the ancient Hoi An town, Quang Nam province (source: https://en.wikipedia.org). The names of islands are the Hon Lao (Pearl), Hon Dai (Long), Hon Mo (Tomb), Hon Kho me (Big Dry), Hon Kho con (Small Dry), Hon La (Leaf), Hon Tai (Ear) and Hon Ong (East Wind). The coral reefs and seagrass beds are widely distributed in the shallow waters of Cu Lao Cham. The researchers have recorded 261 species of Scleractinian coral, 15 species of soft coral, 3 species of fire coral (Milleporidae), 1 species of blue coral (Helioporidae) and 2 species of horny coral (Antipatharia) in this area (Ngoc 2018).

We only surveyed around the large island (Hon Lao) and three other small islands (Hon Tai, Hon La, Hon Dai) (Fig. 1). The sampling sites were sandy beaches, rocky shores and coral reefs. The collection of specimens was approved by Management Board of Cu Lao Cham Marine Protected Area.

Figure 1.  

A map of the study area, the sampling sites are indicated.

Figure 2.  

Taxonomic coverage (by taxonomic order).

Figure 3.  

Taxonomic coverage (by taxonomic family).

This project is designed to obtain as many marine mollusc species as possible in the littoral zone of the Cham Islands.

The project was funded by a grant from the Ministry of Science and Technology of Vietnam, Project code is ĐTĐL.XH-02/16.

The sampling sites were located in the littoral zone of Cham Islands (Fig. 1), including three sites (Bai Huong (Fig. 4), Bai Ong (Fig. 5), Bai Bac (Fig. 6)) at the large island (Hon Lao) and three sites at three other small islands (Hon Tai (Figs 7, 8), Hon La (Fig. 9), Hon Dai (Fig. 10).

Figure 4.  

Bai Huong, Cu Lao Cham.

Figure 5.  

Bai Ong, Cu Lao Cham.

Figure 6.  

Bai Bac, Cu Lao Cham.

Figure 7.  

Hon Tai, Cu Lao Cham.

Figure 8.  

Coral reef in Hon Tai, Cu Lao Cham.

Figure 9.  

Hon La, Cu Lao Cham.

Figure 10.  

Coral reef in Hon Dai, Cu Lao Cham.

Marine molluscs (snails and bivalves) were collected by hand or scoop at the low tide in the different benthic habitats, including the sandy beaches, rocky shores and coral reefs by scuba divers. The sediments were sieved through a 1-mm mesh; the sieve residue was fixed in 95% Ethanol. In the laboratory, the samples were sorted and identified, where possible, to the species level based on taxonomic documents (Abbott and Dance 1986, Carpenter and Niem 1998, Okutani and (Ed.) 2017, Thach 2005, Thach 2007, Thach 2012, Thach 2016).

The scientific names in this paper are based on the identification by experienced experts in the field of the taxonomy of marine molluscs, namely, Dr. Takenori Sasaki from the University Museum, the University of Tokyo and Dr. Do Van Tu from Institute of Ecology and Biological Resources. All taxon names were checked against the Taxon Match tool in the World Register of Marine Species (WoRMS) in order to standardise and correct them, if necessary (http://www.marinespecies.org/aphia.php?p=match).

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The survey conducted in the Cham Islands including the large island (Hon La) and three other small islands (Hon Tai, Hon Dai, Hon La). Cham Islands belongs to Hoi An city, Quang Nam province. This island is located in Central Vietnam.

15.896 and 15.984 Latitude; 108.437 and 108.55 Longitude.

We recorded 145 taxa of bivalves and snails (Table 1, Suppl. material 1). Of these, 116 species have been recorded for the first time in the Cu Lao Cham Island. Gastropoda is dominant with 35 families and 99 species while bivalves were represented by 20 families and 46 species. At the order level, the following were classified into Bivalvia: Arcida (4 species), Cardiida (8 species), Lucinida (3 species), Mytilida (5 species), Ostreida (12 species), Pectinida (4 species) and Venerida (10 species), Gastropoda: Caenogastropoda (2 species), Cycloneritida (2 species), Lepetellida (2 species), Littorinimorpha (28 species), Neogastropoda (45 species), Seguenziida (1 species), Siphonariida (1 species), Trochida (8 species) and unassigned (10 species) (Fig. 2.) The families with the highest species richness were Muricidae (22 species), Cypraeidae (13 species), Conidae (10 species) and Veneridae (8 species). The rest of the families were mostly represented by a single species (Fig. 3). Photos of 40 taxa were presented in Suppl. material 2.