First record of Puerulus mesodontus Chan, Ma & Chu, 2013 (Crustacea, Decapoda, Achelata, Palinuridae) from south of Java, Indonesia

Abstract Background Three specimens of Puerulus mesodontus Chan, Ma & Chu, 2013 (Crustacea, Decapoda, Achelata, Palinuridae) were collected from Palabuhanratu Bay, southern Java, Indonesia. There is no previous record on the presence of the species in Indonesia. This finding represents the first record of this species in Java, Indonesia, and confirms that the species is present in the Indian Ocean. The morphological characters of the species are described. New information This paper contains a new distribution record of a lobster species from Indonesian waters.


Introduction
The deep-sea spiny lobster genus Puerulus Ortmann 1897 lives at depths of 200-700 m in seas of the Indo-West Pacific region facing the Indian Ocean (Holthuis 1991;Chan 1998;Chan et al. 2013). Although the genus is wide in terms of distribution (Chan et al. 2013), it is not of commercial significance (Anrose et al. 2010). However, the genus is economically valued by local communities living on the south coast of Java, Indonesia. Previously, the genus Puerulus contained only four species, namely Puerulus sewelli Ramadan 1938; P. velutinus Holthuis 1963;P. carinatus Borradaile 1910;andP. angulatus Bate 1888 (Holthuis 1991;Chan 2010). However, the morphological complexity of P. angulatus, supported by COI gene sequencing, allowed Chan et al. (2013) to describe five new species, namely P. quadridentis Chan, Ma & Chu, 2013;P. mesodontus Chan, Ma & Chu, 2013; P. sericus Chan, Ma & Chu, 2013;P. gibbosus Chan, Ma & Chu, 2013;and P. richeri Chan, Ma & Chu, 2013. The new species were not reported from Indonesian waters, but P. velutinus and P. angulatus were recorded to occur in these waters (Holthuis 1991;Chan et al. 2013). Here, we report, for the first time, that P. mesodontus occurs in southern Java, Indonesia.

Materials and methods
Specimens were collected from a fish harbour located in Palabuhanratu Bay, southern Java, Indonesia, in May 2015. The map in Fig. 1 shows the location of the bay. Three specimens were collected, preserved in 96% (v/v) alcohol, and transported to the laboratory for assessment of morphological characters and identification. The specimens were deposited in the collection of the Department of Aquatic Resources Management, Bogor Agricultural University, Indonesia. Identification was based on morphological characters using the taxonomic key and original description from Chan et al. (2013). One specimen is shown in Fig. 2

Description
Body moderately pubescent. Carapace similar in length to abdominal somites I-V; surfaces mostly covered with spinules and sharp granules. Supraorbital horn just overreaching the eye and extending to a position approximating the basal one-third of the antennular plate; dorsal margin almost straight, and smooth; followed by a row of three regularly spaced teeth decreasing sharply in size posteriorly; third tooth always prominent. Eye more long than broad (Fig. 3a, b).Postorbital spinules well-developed. Two rows of cervical spines converging anteriorly into a well-developed median spine. Three gastric teeth; the first tooth generally smaller or the third tooth generally larger; sometimes all gastric teeth similar in size or occasionally the first tooth larger; the base of the third tooth less than 1.5-fold wider than the base of the first tooth; the third tooth distinctly distant from the two anterior teeth (Figure 3b). Pereopod V not chelate in males, but chelate in females (Fig. 3c, d). The merus of maxilliped III with an anterodorsal spine (Fig. 3e). The abdomen with a raised granular-to-lobular surface, but the granules not forming distinct rows (Fig. 3f).

Discussion
Most works on Indonesian lobsters have focused on the economically important species, such as diversity, distribution and genetic population of Panulirus penicillatus Olivier 1791 (Chow et al. 2011, Kalih 2012, Abdullah et al. 2014, first record occurrence and sexual dimprphism of Linuparus somniosus Berry andGeorge 1972 (Wowor 1999), size distribution, length-weight relationship, condition factor, and sex ratio of Panulirus versicolor Latreille 1804(Ongkers et al. 2014, and the distribution of Panulirus homarus (Linnaeus 1758), P. longipes (Milne-Edwards 1868), P. ornatus (Fabricius 1798), and Parribacus antarticus (Lund 1793) in Lombok island and its surrounding waters (Kalih 2012). In this paper we present the first record of Puerulus mesodontus from Pelabuhanratu Bay, southern Java. This is also the first record of the species in Indonesia. Chan et al. (2013) describes the distribution of P. mesodontus in the western Pacific as Japan, Taiwan, the Philippines, Papua New Guinea, the Solomon Islands, Vanuatu, New Caledonia, and Fiji.
This finding adds to new records of Indonesian crustaceans, which now include Albunea symmysta (Linnaeus, 1758, Hippa marmorata (Hombron and Jacquinot 1846) , and Hippa adactyla Fabricius 1787. The finding emphasises the fact that Indonesian waters constitute a hotspot of Asian aquatic biodiversity. Future research on the species should focus on distribution, population dynamics, and genetic diversity.