Dispersal, Mimicry, and Geographic Variation in Northern Melanesian Birds
Abstract: I present new information about 34 of the 195 resident land and freshwater bird species of northern Melanesia, an area characterized by a rich avifauna, high endemism, and great geographic variation in morphology. There are many examples of geographic variation in voice, behavior, habitat preference, altitudinal range, vertical stratum, abundance, and nest. Possible vocal convergence or mimicry between sympatric populations of different species is described between the goshawk Accipiter albogularis and the kingfisher Halcyon chloris, between the cuckoo-shrike Coracina [tenuirostris] and other species in its mixed-species foraging flocks, between the white-eyes Zosterops murphyi and Z. rendovae kulambangrae, and between the starlings Aplonis grandis and Mino dumontii. Hybridization is reported between the Bismarck and New Guinea races of the cuckoo Eudynamys scolopacea on Long Island (described as a new subspecies), between the whistlers Pachycephala pectoralis and P. melanura, and between the honey-eaters Myzomela tristrami and M. cardinalis. Cyclones bring Australian species, some of which occasionally remain to breed. Over-water dispersal ability varies greatly, from species that can be seen flying over water any day to species that rarely or never cross water. For instance, a channel 12 km long and only 0.15-1 km wide divides Florida Island into two halves, one of which possesses and the other of which lacks a resident population of the coucal Centropus milo.
Notes on Hawaiian Snake Eels (Pisces: Ophichthidae), with Comments on Ophichthus bonaparti
John E. McCosker
Abstract: The 22 ophichthid eel species of the Hawaiian Islands (including Johnston and the Northwestern Hawaiian Islands) are reviewed, and a key to their identification is provided. New Hawaiian records of Indo-Pacific species include Callechelys catostoma and Ophichthus bonaparti. Callechelys lutea is reported from Johnston Island. Hawaiian and Johnston Island ophichthid species comprise: Apterichtus flavicaudus, Brachysomophis crocodilinus, B. henshawi, Callechelys catostoma, C. lutea, Cirrhimuraena playfairii, Ichthyapus vulturis, Leiuranus semicinctus, Muraenichthys schultzei, Myrichthys colubrinus, M. magnificus, Ophichthus bonaparti, O. erabo, O. kunaloa, O. polyophthalmus, Phaenomonas cooperae, Phyllophichthus xenodontus, Schismorhynchus labialis, Schultzidia johnstonensis, Scolecenchelys cookei, S. gymnota, and S. puhioilo. Additional data are provided for the rare deep-water species Ophichthus kunaloa. The following synonymies are proposed: Ophisurus chrysospilos Bleeker, Poecilocephalus markworti Kaup, Ophichthys episcopus Castelnau, and Ophichthys garretti Günther = Ophichthus bonaparti (Kaup); and Ophichthus retifer Fowler = Ophichthus erabo (Jordan & Snyder). The endemism and distribution of Hawaiian and Johnston Island ophichthids (22.7%) are discussed and compared with those of muraenid eels. Vertebral formulas are provided for all species to facilitate the identification of leptocephali.
Reproductive Ecology of the Gobiid Fish Eviota abax at Nobeoka, Japan, with Notes on Geographic Variation
Masanori Taru and Tomoki Sunobe
Abstract: The reproductive behavior and spawning cycle of the gobiid fish Eviota abax were observed in a rocky tide pool at Nobeoka, Miyazaki, Japan. Both sexes maintained nonterritorial, overlapping home ranges. The spawnings took place at the low tide of neap to spring tidal periods. Matings varied in each spawning cycle, but males did not simultaneously mate with multiple females. Males were larger than females in the spawning pairs. After spawning, only the male guarded the egg mass. Although separated by 900 km, the basic patterns of reproductive ecology were similar at Nobeoka to those reported earlier for this species from Kominato, Chiba, Japan; nest entrances were smaller at Nobeoka than at Kominato, and larger males kept their home ranges longer at Nobeoka.
Reinstatement and Rediagnosis of Catapaguroides setosus and Description of a Second Hawaiian Species of the Genus (Decapoda: Anomura: Paguridea: Paguridae)
Patsy A. McLaughlin and Cory Pittman
Abstract: A species of the hermit crab genus Catapaguroides recently discovered in a sand-dwelling Halimeda community on the island of Maui, Hawaiian Islands, prompted a reexamination of the holotype of Catapaguroides setosus (Edmondson, 1951), described from off the south coast of O`ahu. The latter species, currently considered a junior subjective synonym of Catapaguroides fragilis (Melin), is herein adjudged neither synonymous with C. fragilis nor conspecific with the second Hawaiian species. Catapaguroides setosus is reinstated with full specific rank, rediagnosed, and illustrated. The second species, Catapaguroides hooveri McLaughlin & Pittman, n. sp., is described and illustrated.
Predators of the Invasive Mussel Musculista senhousia (Mollusca: Mytilidae)
Jeffrey A. Crooks
Abstract: Musculista senhousia (Benson in Cantor, 1842) is a soft sediment–dwelling mussel that has spread anthropogenically from its native Asia to North America, Australasia, and Europe. This byssal mat-forming species can become overwhelmingly dominant and have dramatic impacts within invaded ecosystems, but its invasion may meet “ecological resistance” from native predators. In Mission Bay, San Diego, California, three fish species and two shorebirds were found to prey upon the mussel. Experimental results suggest that predation can dramatically impact intertidal mussel populations and may account for observed seasonal declines in the species. Despite the creation of a byssal cocoon, which may afford the mussel some protection, several taxa worldwide have been found to be Musculista predators. In addition, in areas where the mussel is native, humans impact mussel populations by gathering it for animal feed or bait, or to remove it from commercial shellfisheries grounds.
Redescription of the Indo-Pacific Scorpionfish Scorpaenopsis fowleri and Reallocation to the Genus Sebastapistes
John E. Randall and Stuart G. Poss
Abstract: The wide-ranging Indo-Pacific scorpionfish Scorpaenodes fowleri (Pietschmann), long placed in the genus Scorpaenopsis (largely because it lacks palatine teeth), is reclassified in the genus Sebastapistes. It is distinct from the species of Scorpaenopsis in several features: eye not extending above the dorsal profile of the head, large pores of the cephalic lateralis system, nasal pore above and adjacent to posterior nostril with a very small retrorse nasal spine (may be absent) on its upper edge, low ridgelike spines dorsally on the head, preocular spine usually embedded, sphenotic and postorbital spines absent or embedded; posterior lacrimal spine projecting slightly anteriorly, and a single spine posteriorly on the suborbital ridge with a pore-associated spine just below the ridge under the posterior third of the eye. Also significant is its very small size, the smallest of the Scorpaenidae (largest specimen, 37 mm SL; smallest mature female, 18 mm SL). The loss of palatine teeth appears to have occurred independently from the species of Scorpaenopsis. Sebastapistes fowleri is closest to S. strongia, the type species of the genus. In addition to having palatine teeth, S. strongia differs in the strongly retrorse posterior lacrimal spine and in having two spines on the suborbital ridge. The limits of Sebastapistes need reevaluation.
The Ka`ena Highstand of O`ahu, Hawai`i: Further Evidence of Antarctic Ice Collapse during the Middle Pleistocene
Paul J. Hearty
Abstract: Marine isotope stage (MIS) 11 may well represent one of the most significant interglacial highstand events of the past million years. Ocean volume changes charted from coastal exposures imply partial or complete melting of the some of the world’s major ice caps during a middle Pleistocene interglacial. The coastal geology of both Bermuda and the Bahamas yields evidence of an MIS 11 highstand 20 m higher than present. Further support for this catastrophic episode in sea-level history is revealed in subtidal and intertidal deposits at +28 +/- 2 m in O`ahu, Hawai`i. The stratigraphy, petrology, and uplift history of the Hawaiian deposits strongly suggest a correlation with MIS 11, and a compilation of amino acid racemization, uranium/thorium (alpha and mass spectrometry), and electron spin resonance ages shows a scatter between 300 and 550 kyr. When corrected for uplift, the Ka`ena Highstand succession at Wai`anae Health Center (OWH1) reveals a “stepping up” of sea level through the interglaciation, similar to that described in the Bahamas. Previous studies on O`ahu attributed all 28 m elevation of the Ka`ena Highstand to uplift since 0.5 Ma, but now it appears that only 8 m of that was caused by uplift, and the remaining 20 m by eustatic sea-level rise. These findings from O`ahu strengthen evidence for the complete disintegration of the Greenland and West Antarctic ice sheets and partial melting of the East Antarctic ice sheet during the middle Pleistocene. If the instability of polar ice sheets can be linked to prolonged warm interglaciations as the data suggest, then existing conservative predictions for the magnitude of sea-level change by future “greenhouse” warming are seriously underestimated.
Pacific Science Association