Cheilinus

Abstract: The humphead wrasse, Cheilinus undulatus, is the largest living member of the family Labridae, with a maximum size exceeding 2 m and 190 kg. Its geographic range covers much of the Indo-Pacific. The species is not common, recorded maximum adult densities rarely exceeding 20 fish/10,000 m2. Small individuals are typically associated with high coral cover; larger fish are found mainly on outer or deep reefs, steep slopes and passes, singly or in small groups and seagrasses. However, for reproduction the species forms small spawning aggregations of tens to more than one hundred fish. The diet of the humphead wrasse includes large invertebrates and small fishes. The species attains at least 30 years and reaches sexual maturation at about 35–50 cm total length and <5 years of age. Most small adults are female while mainly males exceed 1 m and there is evidence of female to male sex change. The humphead wrasse is of considerable cultural value in some Pacific countries and is among the most prized in the live reef food fish export trade, for which it is often taken in its juvenile size range, either directly for sale or, increasingly, for grow-out to market size. It is also marketed chilled. The species is particularly sensitive to fishing pressure. In most fished areas, density and body size have dropped substantially. It appears to be particularly heavily targeted and depleted in SE Asia and in some places faces extirpation. The humphead wrasse is often taken by night spearfishing and by cyanide, with protection typically weak or non-existent, despite regulations and by a ‘vulnerable’ assessment on the 1996 IUCN Red List. The humphead wrasse has not been reared successfully in hatcheries. Other giant reef fish share many similar problems and detailed study of the humphead wrasse contributes to a better understanding and conservation of all such species. This review examines and evaluates published and gray literature, original unpublished research and correspondence with almost 50 knowledgeable workers. It examines the value of such sources for quickly, but adequately, assessing the conservation and management status and key data gaps in species that are little known, vulnerable, difficult and expensive to study and may require urgent management or conservation action.

Abstract: Age-based demographic parameters were estimated from 164 individuals of the large teleost Cheilinus undulatus from NE Australia. Analysis of sagittal otoliths revealed alternating translucent and opaque bands in which annual periodicity of a single opaque band was confirmed. A size-at-age plot of 164 individuals showed that males grew significantly faster than females, achieving a size of 140 cm fork length (FL). Male growth trajectories were essentially linear. Maximum ages recorded were 25 yr for males and 30 yr for females. Estimates of annual total mortality ranged from 0.10 to 0.14. The age distribution of males suggests protogyny with male recruitment into the population commencing at 9 yr at a size threshold of 70 cm. The age distribution of females confirmed that not all individuals changed sex. Analysis of the sample size revealed a strongly skewed distribution with a modal size peak at 50 to 70 cm and an extended tail of larger individuals. Estimates of size distributions from underwater surveys revealed a right-skewed distribution similar to that observed in our sample. An analysis of size distributions in labrid fishes shows that large size (>75.0 cm FL) is rare (4.5% of 559 species). Demographic analysis of C. undulatus and of large labrid fishes demonstrates that they share a dynamic demography with fast indeterminate growth rates and relatively short life spans.

Abstract: In recent years there has been increasing interest in conserving fish habitats. However, fish-habitat associations, particularly nursery habitat for early juvenile stages, are poorly known for most reef fishes. Using mark-recapture techniques, I examined among-habitat variation in settlement, post-settlement growth, and persistence, and movement in 3 large, vulnerable, and commercially important reef fishes: the humphead wrasse Cheilinus undulatus, the squaretail coralgrouper Plectropomus areolatus, and the camouflage grouper Epinephelus polyphekadion. Both the humphead wrasse and the coralgrouper appeared to utilize specific nursery habitats. Settlement, growth, and persistence of humphead wrasse were highest in branching coral structures mixed with bushy macroalgae (BCMA). Of all tagged C. undulatus recaptured in intermediate or adult habitats, 80% were tagged post-settlement in BCMA. Early juvenile P. areolatus were found almost exclu- sively in coral rubble habitats on the slopes of tidal channels, at a narrow depth range of 5 to 7 m. This dependence on one habitat type could render this species vulnerable to shipping or dredging opera- tions or other forms of coastal development. E. polyphekadion appeared to be a habitat generalist, and no specific nursery habitat could be identified. In summary, spatial management (e.g. implemen- tation of marine protected areas) should prioritize habitats for conservation according to their value as essential nursery or spawning habitats for target species needing protection.