Diversity of coastal mysids from Pulau Tinggi , Sultan Iskandar Marine Park , Malaysia

A checklist of the order Mysida from Pulau Tinggi, Sultan Iskandar Marine Park, Johor, Malaysia is presented. With the aid of an epibenthic sledge, a total number of 9,239 mysids were collected during years 2012–2013 from two fixed stations of seagrass bed in Pulau Tinggi. So far there are 13 species, 10 genera, and 6 subfamilies of mysids. Of these, one species Siriella media Hansen, 1910 is recorded as new to Pulau Tinggi. The checklist presented herein includes the reference to each species’ original description, type locality, information on geographical distribution.

Mysids of Pulau Tinggi, Sultan Iskandar Marine Park Nauplius, 26: 2018037 This checklist, however, is the first one regarding the order Mysida occuring around the coastal waters of Pulau Tinggi at Sultan Iskandar Marine Park (SIMP).
Pulau Tinggi in Johor has revealed an overwhelming diversity of crustaceans.Numerous newly described crustacean species have been named after the locality since 2010 (see Lim et al., 2010;Azman and Melvin, 2011;Lim et al., 2015;Lim et al., 2017;Chew et al., 2016).In addition, Lim et al. (2012) and Chew et al. (2014) also added two new genera named Microtripus Lim, Rahim and Takeuchi, 2012 (Amphipoda) and Tinggianthura Chew, Rahim and bin Haji Ross, 2014 (Isopoda) to the diversity of small crustaceans in Pulau Tinggi.To date, only studies by Gan et al. (2010) and Tan et al. (2015) have been done on mysids of Pulau Tinggi with one recently new published record of Rhopalophthalmus longipes Ii, 1964 (Tan andAzman, 2017).
Mysids or opossum shrimps are one of the most morphologically diverse groups among crustaceans.Probably because of their small size, cryptic and swimming behavior, they remain unnoticed.It is our hope that this checklist will further assist potential research on taxonomy, biodiversity, ecology, and biogeography.The main objective of this paper is to provide an updated list of the coastal mysids occurring in the seagrass area of Pulau Tinggi.In addition, this work revisits the mysid biodiversity of Pulau Tinggi with the goal of complementing and updating previous contributions, and identifying venues for future research.

Mysids of Pulau Tinggi, Sultan Iskandar Marine Park
Nauplius, 26: 2018037 Rawa, Pulau Besar, Pulau Tengah, Pulau Hujung, Pulau Mensirip, Pulau Harimau, Pulau Goal, Pulau Mentinggi, Pulau Sibu, Pulau Sibu Hujung, Pulau Aur and Pulau Pemanggil), that are also known as East Johor Island Archipelago (EJIA) ( Jacqueline, 2013).Pulau Tinggi is considered one of the biggest islands in the SIMP, with a total area of about 16 km 2 (Azman et al., 2008) off the East Coast of Peninsular Malaysia (South China Sea).A two-tiered epibenthic sledge (140 μm) was utilized when collecting the specimens with three replicates at each station.The epibenthic sledge is illustrated in Fig. 2. All samples were preserved in 5% formaldehydeseawater buffered solution.Mysid individuals were grouped into several stages according to Mauchline (1980): (i) juvenile: secondary sexual characteristics absent; (ii) immature male: secondary sexual characteristics in development; (iii) immature female: marsupium without embryo and still in development stage with a size smaller than mature females; (iv) mature male: secondary sexual characteristics developed completely; (v) mature female: marsupium developed completely but without embryos.
In this study, a complete list of coastal mysid species recorded in Pulau Tinggi, Johor is presented.Species within each family were listed alphabetically, followed by authority name.References and distribution records of the checked species were given in details, including  the local distribution of those species, denoting which species they were from that found locally in Malaysian waters.In the next category, information on general distribution was summarized on the basis of all the available published articles.Habitus drawings of all the species were prepared with aid of a camara lucida attached to a Leica DMLB light microscope and they were digitally inked using the methods described in Coleman (2003;2009).Materials were deposited in the Muzium Zoologi, Universiti Kebangsaan Malaysia (UKMMZ), Malaysia. resulTs All specimens were collected at two stations (Fig. 1).Most of the species have been previously recorded by Gan et al. (2010), although there was only one new record of Rhopalophthalmus longipes (Tan and Azman 2017) that has been added on the species list of mysid from Pulau Tinggi.As a result of this study, another species, Siriella media Hansen, 1910, has been added on the list.Total number of individuals for each collected species are shown in Tab. 2. Erythrops minutus Hansen, 1910 (Fig. 3A) Type locality.Ko Kham, Gulf of Siam, Thailand (Hansen, 1910).
Recorded habitat.Coastal shallow-water and often found among seaweed and in seagrass bed.
Recorded habitat.Oceanic, pools on sandy coral reefs and seagrass bed.

disCussion
With a total of 13 species, 10 genera and 6 subfamilies of mysids, the present study compiles the largest biodiversity of mysids, recorded for East Coast of Peninsular Malaysia.As pointed out by Tan et al. (2014), out of 41 species recorded from the waters of Peninsular Malaysia, 36 species were from the West Coast of Peninsular Malaysia.Nevertheless, differences in species composition are mostly related to the sampling effort and the method used when collecting mysids.For example, the emergence traps are very efficient in collecting infaunal forms from the soft sediments in subtidal areas, including the smaller mysid species and the juveniles; these forms comprise most of the tropical species, which are not collected with epibenthic sledge (Zalina and Othman, 1994;Gan et al., 2010).Therefore, different sampling methods employed in the different localities and habitats complement each other to have a better collection in terms of the diversity of mysids from Malaysian coast.
Although the species richness of the patchy seagrass bed reported here was significantly higher than in other studies, the diversity and distribution patterns of mysids clearly corresponded to those observed in similar ecosystems.To mention previous related studies, Gan et al. (2010) identified 11 species from the seagrass bed of Pulau Tinggi and Barberá-Cebrián et al. (2002) identified seven species in the seagrass beds of Posidonia oceanica and Cymodocea nodosa from the Mediterranean coast of Alicante (Spain).It seems that a greater habitat complexity implies an increase in species diversity and abundance (Orth 1977(Orth , 1992;;Young, 1981;Stoner, 1983;Orth et al., 1984;Stoner and Lewis, 1985).
The number of species found herein, however, still underestimates the diversity of mysids of this region due to lack of adequate sampling, especially along the Northern Coast of Peninsular Malaysia, and also Sabah and Sarawak.In addition, appropriate equipment and expertise are particularly required, and then diverse habitats along the shoreline regions would certainly present different groups of species that need to be documented.

aCKnowledgeMenTs
We sincerely thank Mr. Shamsul Bahar, Dr. Melvin Chew, Mr. Goh Zhe Zuan, Mr. Loke Hai Xin, Ms. Tan Ming Kun, and Mr. Tan Kok Kiong for their endless help and support throughout the process of collecting specimens.The authors would also like to express their gratitude to Universiti Kebangsaan Malaysia, Sultan Iskandar Marine Park-Johor National Parks, and the Department of Marine Park Malaysia for giving full cooperation.This research was supported by Universiti Kebangsaan Malaysia under Grant No. LIV-2015-02.

Table 1 .
Coding and field parameters of each examined material