Long-term changes in structure of fish communities on coral reefs infested by the coralfeeding starfish Acanthasterplanci were determined using 20 mZ visual transects. We censused a living coral reef consisting mainly of staghorn Acropora spp. at Saluyama Bay and a dead coral reef with low structural complexlty of coral branches (about 2 yr after A. planci infestation) at Amitori Bay, Iriomote Island (Ryukyu Islands, Japan) in September 1984. Two yr later, we recensused the dead coral reef, which had changed into a flat plain of unstructured coral rubble ('rubble reef'). Mean numbers of species and individuals per transect severely decreased in the following order of reef types: (1) living reef (1984). (2) dead reef (1984), and (3) rubble reef (1986). Correlated with these decreases in numbers were several patterns: (1) coral-polyp feeders completely &sappeared on both dead and rubble reefs, probably due to absence of food; (2) numbers of resident species and individuals decreased on the dead reef, perhaps due to decrease in living space or shelter associated with the reduction in structural complexity of coral branches; and (3) numbers of species and individuals of both resident and visitor fishes declined on the unstructured rubble reef, likely due to shortage of living space and food.

CDC-like kinase phosphorylation of serine/arginine-rich proteins is central to RNA splicing reactions. Yet, the genomic network of CDC-like kinase-dependent RNA processing events remains poorly defined. Here, we explore the connectivity of genomic CDC-like kinase splicing functions by applying graduated, short-exposure, pharmacological CDC-like kinase inhibition using a novel small molecule (T3) with very high potency, selectivity, and cell-based stability. Using RNA-Seq, we define CDC-like kinase-responsive alternative splicing events, the large majority of which monotonically increase or decrease with increasing CDC-like kinase inhibition. We show that distinct RNA-binding motifs are associated with T3 response in skipped exons. Unexpectedly, we observe dose-dependent conjoined gene transcription, which is associated with motif enrichment in the last and second exons of upstream and downstream partners, respectively. siRNA knockdown of CLK2-associated genes significantly increases conjoined gene formation. Collectively, our results reveal an unexpected role for CDC-like kinase in conjoined gene formation, via regulation of 3′-end processing and associated splicing factors.

To clarify the feeding habits of fishes in tropical seagrass beds on coral reefs, the gut contents of 53 fish species, collected in an Enhauls acoroides-dominated bed at Iriomote Island, southern Japan, were examined. Ontogenetic changes in food preference were recognized in 9 species, including lethrinids, mullids, pomacentrids, labrids, and scarids. Cluster analysis based on dietary overlaps showed that the seagrass fish assemblage comprised seven feeding guilds (small-crustacean, large-crustacean, plant, detritus, hard-shelled mollusc, fish, and planktonic-animal feeders). Of these, small-crustacean feeders were the most abundantly represented. On the other hand, planktonic-animal and hard-shelled mollusc feeders were each represented by only two species. Compared with previous studies on the feeding habits of temperate seagrass fishes, the present fish assemblage was characterized by larger species numbers of detritivores, herbivores, and piscivores and fewer planktonic-animal feeders.

ABSTRACT. A long-term monitonng study was conducted at Inomote Island (Ryukyu Islands, Japan) to explore the responses of a disturbed adult fish assernblage to the recovery of coral on a large reef degraded by an outbreak of the coral-feeding starfish Acanthaster planci. In 1987, 5 yr after the outbreak, I censused a reef in which aii of the arborescent corals had been broken apart and the reef formation changed into a flat plain of unstructured rubble. Species nchness and numencal density of fishes on the dead reef had decreased severely. Natural recovery of the dead reef was mitiated mainly by larval recruitment of branching Acropora corals in 1989. Since that time, fish species nchness and density on the recovering reef have increased steadily with the increasing percentage cover of live corals. In 1995 to 1997, when the reef had almost 100% live coral cover, most fish assemblage properties (e.g., species numbers and abundances of the collective assemblage and component ecological groups) on the reef did not differ significantly from those on a nearby reef consisting mostly of arborescent Acropora. which had not suffered A. planci predation. The sirnilanty index indicated about 90% resemblance in species composition of the fish assernblages on the recovered and undisturbed reefs. These results demonstrate that the structure of the disturbed fish assemblage had returned to its preperturbation state on the near-completion of coral recovery.

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