Haplostylus pacificus ( Hansen, 1912 )

Yolanda, Rofiza, Ambarwati, Reni, Rahayu, Dwi Anggorowati, Budijastuti, Widowati, Fitrihidajati, Herlina, Kuntjoro, Sunu, Rachmadiarti, Fida & Purnomo, Tarzan, 2023, An annotated checklist of the species of Lopogastrida and Mysida (Crustacea Peracarida) from Thailand and its adjacent waters, Zootaxa 5244 (3), pp. 201-232 : 209

Haplostylus pacificus ( Hansen, 1912)

= Gastrosaccus pacificus Hansen, 1912

Type locality. Gilbert Islands ( Hansen 1912) .

Record from Thailand. South-eastern Andaman Sea, next to Phuket Island ( Fukuoka & Murano 2002).

Habitat and depth range. Marine, depth: 20–44 m ( Fukuoka & Murano 2002) .

Distribution. The Gilbert Islands ( Hansen 1912), Andaman Islands (W.M. Tattersall 1922), Philippines (W.M. Tattersall 1951), Australia ( Băcescu 1979; Lowry & Stoddart 2003), Japan ( Murano 1990; Fukuoka & Murano 1997), Andaman Sea ( Fukuoka & Murano 2002) and Malaysia ( Zalina & Othman 1994).

Remarks. The morphology of this species is very close to H. multispinosus , however, in H. pacificus , (1) uropodal endopod with 7 or 8 mesial spines, (2) the telson laterally armed with 8–11, somewhat sparsely placed spines and distomedial groove reaching the level of the base of the penultimate spine, (3) distal segment of male third pleopodal exopod abruptly narrowing in distal 2/5 and lash-like terminal seta smooth, not barbed; while in H. multispinosus , (1) uropodal endopod with 13–14 mesial spines, (2) the telson laterally armed with 10–13 closely spaced, rather long spines and distomedial groove reaching level of distal third spine, (3) distal segment of male third pleopodal exopod slightly narrowing in distal 1/6 and lash-like terminal seta barbed ( Hanamura 1998).