Volume 12, Issue 2, December 2006
Volume 12, Issue 2 – December 2006
Eugenie Clark, Stephen N. Kogge, Diane R. Nelson, Thomas K. Alburn and John F. Pohle: Burrow distribution and diel behavior of the coral reef fish Pholidichthys leucotaenia (Pholidichthyidae), pp. 45-82
We studied the behavior of adult and juvenile Pholidichthys leucotaenia on coral reefs in three areas of its range: the Solomon Islands (Russell and Florida Islands), Papua New Guinea (Milne Bay Province), and Borneo, Malaysia (Mabul, Kapalai, and Sipadan). Using remote video for periods up to 55 h, we monitored diel behavior of adults (to 57 cm TL) at their burrow entrances. A customized miniature underwater video endoscope enabled us to view inside the burrows. Yolk-sac stage larvae (6-7 mm TL) and planktivorous juveniles (7-11 mm TL) are site-attached. At dawn young emerged from their burrows in swarms of dozens to thousands. Larval swarms stayed close to their burrow entrance, but swarms of juveniles swam away to feed on plankton. Juveniles resemble the sympatric, venomous catfish, Plotosus lineatus (Plotosidae), in appearance and unique swarming behavior. During the day, adult Pholidichthys leucotaenia excavated and cleaned their burrows by spitting out sand and rubble at the entrance. At dusk larvae and juveniles retired into their home burrows with two or three adults. None emerged from burrows at night. Clusters of larvae or juveniles hung from the burrow ceiling by mucus secreted from glands on their heads and often were scooped into mouths of adults and then released apparently unharmed. The food source of adult P. leucotaenia remains unknown. An undescribed galeommatid bivalve lives in the fish’s burrows but apparently is not their food source. Our specimens raised at Mote Marine Laboratory on standard fish food showed strong asymmetry in color patterns during development to the adult stage.
A swarm of thousands of juvenile Pholidichthys leucotaenia (each ca 5 cm TL) streaming into their home burrow near sunset from a distant feeding area over 30 m away. White sand “apron” spreads from burrow entrance formed by the cryptic adults during daytime cleaning activity. Depth about 10 m. Observation Point, Papua New Guinea. Photo by Bob Halstead, 2000.
John E. Randall: Dactylanthias baccheti, a new species of anthiine fish (Perciformes: Serranidae) from the Tuamotu Archipelago, pp. 83-88
The anthiine fish Dactylanthias baccheti is described from one 204-mm specimen collected from a depth of 200-250 m off Takaroa Atoll, Tuamotu Archipelago. It is distinct from the one other species of the genus, D. aplodactylus from Indonesia, in having a more oblique mouth, broader interorbital space, different shape of fins, slightly higher counts of dorsal soft rays, pectoral rays, and lateral-line scales, and in life color.
Holotype of Dactylanthias aplodactylus, RMNH 5457, 170 mm (after Bleeker, 1873-1876: Perc. Tab. IV, fig. 3)