Bioacoustics of Trizocheles sakaii

Remarks . The present specimens are identified with Trizocheles sakaii because of the following characteristics: palms of chelipeds armed with two to four rows of spines; carpi of chelipeds with stridulating rods or tubercles; propodi of second pereopods moderately stout (3.6 times as long as wide or less), armed only with dorsodistal spine, otherwise unarmed. Comparison with the material from Japan and Taiwan failed to detect significant morphological differences from the Papua New Guinea specimens, although there is a wide geographical gap between Papua New Guinea and the Japanese Archipelago. With regard to the living coloration, minor differences are seen: the male specimen from stn DW 3745 (MNHN-IU-2011-3490) has white distal bands on the meri of the chelipeds and ambulatory legs ( Fig. 5 B), whereas such white bands are not seen on the meri of the chelipeds in the specimen from Taiwan (McLaughlin et al . 2007: 36, unnumbered fig.). Forest (1987a) attributed all records of Pylocheles spinosus from Japanese waters (Ortmann 1892; Balss 1913; Yokoya 1933; Miyake 1978, 1982) to Trizocheles sakaii , and this was followed by McLaughlin & Lemaitre (2009). Komai (2013) clarified this by noting that Ortmann’s (1892) specimen actually represented T. albatrossi instead of T. sakaii , and that two species, T. albatrossi and Pomatocheles jeffreisi , were mixed up in the material identified as Pylocheles spinosus by Miyake (1978).