Cephalopholis Urodeta Research Articles

KARAKTERISTIK IKAN KERAPU DI PASAR ARUMBAI AMBON

Arumbai Market in Ambon City, Maluku Province, is a central hub for the trade of fishery products, particularly groupers. This study aims to describe the origin of grouper catches and to identify the species and sizes of groupers marketed at Arumbai Market. Groupers, which belong to the family Serranidae, are the primary predators in coral reef ecosystems. Fish identification was conducted based on Allen's guide and verified through FishBase. The study was conducted from December 2022 to February 2023 using a survey method through direct observation and interviews. Data were analyzed descriptively and presented in tables and graphs. The results showed that groupers at Arumbai Market come from four main locations: Manipa (34.47%), Liang (26.81%), Latuhalat (24.26%), and Pulau Tiga (14.47%). Eight dominant species of groupers in this market are Variola albimarginata (44.64%), Cephalopholis miniata (20.60%), Epinephelus fasciatus (12.45%), Epinephelus ongus (6.44%), Cephalopholis urodeta (6.44%), Cephalopholis sonnerati (5.58%), Epinephelus areolatus (3.00%), and Epinephelus fuscoguttatus (0.86%). Grouper sizes vary, with Cephalopholis miniata having a maximum size of 27.1 cm and a minimum size of 19.9 cm. This study provides essential information on the origin of catches, species dominance, and sizes of groupers marketed, which can serve as a basis for better fishery management. These findings indicate a significant potential for grouper trade in the region and highlight the importance of sustainable management to preserve the continuity of coral reef ecosystems and grouper populations.

Changes in population biology of three coral reef fishes in the South China Sea between 1998–1999 and 2016–2019

The decline of coral reefs and their fish has attracted worldwide attention. The South China Sea is the important center of coral reefs. Reef-fish is a crucial component in coral reef ecosystem. However, studies on the long-term variation in the biololgy of coral reef fish in the South China Sea are very lacking. To enhance our understanding of variation in reef fish biology in the South China Sea, we investigated long-term changes in some biological indicators of three dominant coral reef fishes (Lutjanus kasmira, Gnathodentex aureolineatus, and Cephalopholis urodeta) at the Yongshu Reef of the South China Sea between 1998–1999 and 2016–2019, and examined the effects of fishing and sea surface temperature on their biology. Compared with 1998–1999, average body length, average body mass, large fish indicator, feeding level and relative fatness of Lutjanus kasmira and Gnathodentex aureolineatus decreased in 2016–2019, but Cephalopholis urodeta did not. The relative fatness was positively correlated with the feeding level, which indicated that the decline of feeding level decreased the relative fatness. Fishing had the most important negative impact on biological changes. In the past two decades, Lutjanus kasmira had the most obvious decline in size and relative fatness, followed by Gnathodentex aureolineatus, but Cephalopholis urodeta had almost no decline. We hypothesized that different coral reef fishes have different abilities to maintain population stability under external pressures, and the differences in vulnerability of three fish species were the main reasons for their different responses to external pressures. To promote the conservation of coral reef fish, we recommend taking rigorous management to protect habitat.

Length‐weight relationships of three demersal reef fishes caught by longline inhabiting the marine waters of gulf of Mannar, India

The length-weight relationships were estimated for three reef fish species caught in the Gulf of Mannar, India using experimental longlines. The longline fishing took place from December, 2019 to September, 2021 in fortnightly intervals, using longlines (2400 m, 2700 m and 3360 m each), equipped with each 600 various “J” type fishing hooks (straight, reversed, kirbed). The hook sizes used were standard size numbers 6, 9, and 12. The longlines fabricated with polyamide monofilament line were operated from 20 to 50 m depth for 3–5 hours each time. Overall, 81,000 hooks were deployed in 45 fishing trials. The total length and total weight of the combined sex group was recorded nearest to 0.1 cm and 0.01 g, respectively. By using the logarithmic transformed data, linear regression analysis was performed to calculate a and b values for three fish species to establish length-weight relationships. The parameters for the length-weight equations for three species are provided along with respective coefficient of correlation and the 95% confidence intervals. A new maximum total length was recorded for two grouper species, viz., Epinephelus faveatus (36.5 cm) and Cephalopholis urodeta (46.0 cm).

Next generation sequencing yields the complete mitochondrial genome of the darkfin hind Cephalopholis urodeta (Serranidae) from the Mischief Reef, South China Sea

The complete mitochondrial genome of the Cephalopholis urodeta (Serranidae: Epinephelinae) was sequenced by next-generation sequencing method on the basis of one female specimen collected from coral reef areas at the Mischief Reef, South China Sea. The mitogenome is 16,593 bp in length, including 13 protein-coding genes, 22 tRNA genes, two rRNA genes and a D-loop region. The overall content of A + T is 55.66%, which is significantly higher than the C + G content (44.34%). Among four bases, C shows the lowest frequency (15.99%). Phylogenetic tree based on the 13 protein-coding genes was constructed for analyzing the position of C. urodeta. The results provide useful insights into further studies on population genetics and phylogenetics of groupers.

Assessment of Coral Reef Fish Stocks From the Nansha Islands, South China Sea, Using Length-Based Bayesian Biomass Estimation

The South China Sea (SCS) is one of the world’s main centers for coral reef diversity, with more than one-third of all reef fish species being found in this area. Some indications of overfishing have appeared in typical coral reefs of the SCS, as fish diversities have declined and the average body lengths of dominant fish species have decreased. However, only few assessments of coral reef fish stocks have been conducted, due to insufficient available data. In this study, we applied a newly developed length-based Bayesian biomass (LBB) estimation method to assess 10 dominant coral reef fish species from three main reefs (Yongshu Reef, Zhubi Reef, and Meiji Reef) of the Nansha Islands, SCS. Simulations indicated the estimated parameters were not sensitive to sample sizes (more than 100) using the LBB method. Our results showed that the relative biomass levels (B/BMSY) of Cephalopholis spiloparaea, Cephalopholis urodeta, Lutjanus gibbus, Gnathodentex aureolineatus, Pentapodus caninus, and Cheilinus fasciatus were between 0.16 and 0.45, suggesting an overfishing status; the relative biomass levels of Epinephelus merra, and Parupeneus crassilabris were 0.98 and 1.1, respectively, indicating that they were fully exploited; and the relative biomass levels of Lutjanus kasmira and Melichthys vidua were 1.3 and 2.5, respectively, indicating the populations were in good conditions. The estimates of Lc/Lc_opt were less than one for seven stocks, suggesting that the stocks were suffering from growth overfishing. Therefore, we emphasize the need to reduce fishing mortality and increase the mesh size of the coral reef fishery in the Nansha Islands, to achieve a sustainable yield and biomass.

Deep Insights into Gut Microbiota in Four Carnivorous Coral Reef Fishes from the South China Sea.

Investigations of gut microbial diversity among fish to provide baseline data for wild marine fish, especially the carnivorous coral reef fishes of the South China Sea, are lacking. The present study investigated the gut microbiota of four carnivorous coral reef fishes, including Oxycheilinus unifasciatus, Cephalopholis urodeta, Lutjanus kasmira, and Gnathodentex aurolineatus, from the South China Sea for the first time using high-throughput Illumina sequencing. Proteobacteria, Firmicutes, and Bacteroidetes constituted 98% of the gut microbiota of the four fishes, and 20 of the gut microbial genera recovered in this study represent new reports from marine fishes. Comparative analysis indicated that the four fishes shared a similar microbial community, suggesting that diet type (carnivorous) might play a more important role in shaping the gut microbiota of coral reef fishes than the species of fish. Furthermore, the genera Psychrobacter, Escherichia-Shigella, and Vibrio constituted the core microbial community of the four fishes, accounting for 61–91% of the total sequences in each fish. The lack of the genus Epulopiscium in the four fishes was in sharp contrast to what has been found in coral reef fishes from the Red Sea, in which Epulopiscium was shown to be the most dominant gut microbial genus in seven herbivorous coral reef fishes. In addition, while unique gut microbial genera accounted for a small proportion (8–13%) of the total sequences, many such genera were distributed in each coral reef fish species, including several genera (Endozoicomonas, Clostridium, and Staphylococcus) that are frequently found in marine fishes and 11 new reports of gut microbes in marine fishes. The present study expands our knowledge of the diversity and specificity of gut microbes associated with coral reef fishes.

A morphological and functional basis for maximum prey size in piscivorous fishes.

Fish predation is important in shaping populations and community structure in aquatic systems. These predator-prey interactions can be influenced by environmental, behavioural and morphological factors. Morphological constraints influence the feeding performance of species, and interspecific differences can thus affect patterns of resource use. For piscivorous fishes that swallow prey whole, feeding performance has traditionally been linked to three key morphological constraints: oral gape, pharyngeal gape, and the cleithral gape. However, other constraints may be important. We therefore examine 18 potential morphological constraints related to prey capture and processing, on four predatory species (Cephalopholis urodeta, Paracirrhites forsteri, Pterois volitans, Lates calcarifer). Aquarium-based experiments were then carried out to determine capture and processing behaviour and maximum prey size in two focal species, C. urodeta and P. forsteri. All four species showed a progressive decrease in gape measurements from anterior to posterior with oral gape ≥ buccal ≥ pharyngeal ≥ pectoral girdle ≥ esophagus ≥ stomach. C. urodeta was able to process prey with a maximum depth of 27% of the predators’ standard length; for P. forsteri it was 20%. C. urodeta captured prey head-first in 79% of successful strikes. In P. forsteri head-first was 16.6%, mid-body 44.4%, and tail-first 38.8%. Regardless of capture mode, prey were almost always swallowed head first and horizontally in both focal species. Most internal measurements appeared too small for prey to pass through. This may reflect the compressibility of prey, i.e. their ability to be dorsoventrally compressed during swallowing movements. Despite examining all known potential morphological constraints on prey size, horizontal maxillary oral gape in a mechanically stretched position appears to be the main morphological variable that is likely to affect maximum prey size and resource use by these predatory species.

Long-term exposure to elevated carbon dioxide does not alter activity levels of a coral reef fish in response to predator chemical cues

Levels of dissolved carbon dioxide (CO2) projected to occur in the world’s oceans in the near future have been reported to increase swimming activity and impair predator recognition in coral reef fishes. These behavioral alterations would be expected to have dramatic effects on survival and community dynamics in marine ecosystems in the future. To investigate the universality and replicability of these observations, we used juvenile spiny chromis damselfish (Acanthochromis polyacanthus) to examine the effects of long-term CO2 exposure on routine activity and the behavioral response to the chemical cues of a predator (Cephalopholis urodeta). Commencing at ~3–20 days post-hatch, juvenile damselfish were exposed to present-day CO2 levels (~420 μatm) or to levels forecasted for the year 2100 (~1000 μatm) for 3 months of their development. Thereafter, we assessed routine activity before and after injections of seawater (sham injection, control) or seawater-containing predator chemical cues. There was no effect of CO2 treatment on routine activity levels before or after the injections. All fish decreased their swimming activity following the predator cue injection but not following the sham injection, regardless of CO2 treatment. Our results corroborate findings from a growing number of studies reporting limited or no behavioral responses of fishes to elevated CO2.Significance statementAlarmingly, it has been reported that levels of dissolved carbon dioxide (CO2) forecasted for the year 2100 cause coral reef fishes to be attracted to the chemical cues of predators. However, most studies have exposed the fish to CO2 for very short periods before behavioral testing. Using long-term acclimation to elevated CO2 and automated tracking software, we found that fish exposed to elevated CO2 showed the same behavioral patterns as control fish exposed to present-day CO2 levels. Specifically, activity levels were the same between groups, and fish acclimated to elevated CO2 decreased their swimming activity to the same degree as control fish when presented with cues from a predator. These findings indicate that behavioral impacts of elevated CO2 levels are not universal in coral reef fishes.

Hybridisation among groupers (genus Cephalopholis) at the eastern Indian Ocean suture zone: taxonomic and evolutionary implications

Hybridisation is a significant evolutionary process that until recently was considered rare in the marine environment. A suture zone in the eastern Indian Ocean is home to numerous hybridising sister species, providing an ideal opportunity to determine how hybridisation affects speciation and biodiversity in coral reef fishes. At this location, hybridisation between two grouper (Epinephelidae) species: Cephalopholis urodeta (Pacific Ocean) and C. nigripinnis (Indian Ocean) was investigated to determine the genetic basis of hybridisation and to compare the ecology and life history of hybrids and their parent species. This approach aimed to provide insights into the taxonomic and evolutionary consequences of hybridisation. Despite clear phenotypic differences, multiple molecular markers revealed hybrids, and their parent species were genetically homogenous within and (thousands of kilometres) outside of the hybrid zone. Hybrids were at least as fit as their parent species (in terms of growth, reproduction, and abundance) and were observed in a broad range of intermediate phenotypes. The two species appear to be interbreeding at Christmas Island due to inherent biological and ecological compatibilities, and the lack of genetic structure may be explained by three potential scenarios: (1) hybridisation and introgression; (2) discordance between morphology and genetics; and (3) incomplete lineage sorting. Further molecular analyses are necessary to discriminate these scenarios. Regardless of which applies, C. urodeta and C. nigripinnis are unlikely to evolve in reproductive isolation as they cohabit where they are common (Christmas Island) and will source congeneric mates where they are rare (Cocos Keeling Islands). Our results add to the growing body of evidence that hybridisation among coral reef fishes is a dynamic evolutionary factor.

Complete mitochondrial genome of darkfin hind Cephalopholis urodeta (Perciformes, Epinephelidae)

Darkfin hind, Cephalopholis urodeta, belongs to the subfamily Epinephelinae. It is one of the most important fish species in coral-reef ecosystem. In this study, the complete mitochondrial (mt) genome of C. urodeta has been determined. It was 16,592 bp in length and contained 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes and 2 non-coding regions. The mitogenome sequence of C. urodeta shared 94% and 92% similarity to that of C. sonnerati and C.sexmaculata, respectively. Phylogenetic tree was made based on the concatenated sequences of 12 protein-coding genes on mtH-strand. All the results provide insights into the evolution in the subfamily Epinephelinae.

Diplectanum parvus sp. nov. (Monogenea, Diplectanidae) from Cephalopholis urodeta (Perciformes, Serranidae) of New Caledonia

AbstractDiplectanum parvus sp. nov. is described from the coral reef fish Cephalopholis urodeta collected off New Caledonia, South Pacific, and is the first diplectanid described from this fish. The new species has a very small male copulatory organ (24 μm in length) and a minute body (246 μm in length) and is close to D. nanus Justine, 2007 from which it can be distinguished by the shape of dorsal bars and various measurements. These species belong to a group of diplectanids found in groupers (Serranidae, Epinephelinae), characterised by small funnel-shaped male copulatory organs and no sclerotized female organs. The attribution of these parasites to Diplectanum Diesing is provisional. Other parasites are briefly listed.

Feeding habits of juvenile darkfin hind Cephalopholis urodeta (Serranidae) at Iriomote Island, southern Japan

The feeding habits of juvenile serranids, Cephalopholis urodeta, were examined on the basis of 104 specimens (≤100mm in total length, TL) collected from coral reef areas at Iriomote Island, Ryukyu Islands, Japan, from May to September between 1998 and 2001. Thirtyone (29.8%) of the specimens collected had empty stomachs, the overall mean stomach fullness index being low (0.94). The most important prey comprised small fishes and shrimps, food preferences not differing among three juvenile size classes (≤60, 61-80 and 81-100mm TL).

Evidence of protogynous hermaphroditism in the darkfin hind Cephalopholis urodeta (Serranidae) at Iriomote Island, southern Japan

Evidence of protogynous hermaphroditism in the darkfin hind Cephalopholis urodeta (Serranidae) at Iriomote Island, southern Japan

Habitat association and depth distribution of two sympatric groupers of the genus Cephalopholis (Serranidae: Epinephelinae)

Habitat association and depth distribution of two sympatric coral reef groupers of the genus Cephalopholis were examined at Rota, Mariana Islands. The two species are similar in body size, morphology, and social organization. In this study, they differed in their association with habitat and microhabitat and in depth distribution. Cephalopholis spiloparaea occurred on the reef slope between the reef terrace and deep sand flats at depths between 15 and 26 m. This species was associated mainly with Porites rus corals. Cephalopholis urodeta occurred largely on the upper reef terrace at 1–12 m. This species was associated mainly with coral pavement. The observed pattern of segregation might be the result of competitive or noncompetitive interactions or of phylogenetic constraints, but the exact mechanism or combination thereof remains unknown.

Feeding habits of the darkfin hind Cephalopholis urodeta (Serranidae) at Iriomote Island, southern Japan

: The feeding habits of the serranid fish Cephalopholis urodeta were examined on the basis of 204 adult specimens collected from coral reef areas at Iriomote Island, Ryukyu Islands, Japan. Sampling was conducted in November 1997 and February, May, and August 1998. Among the specimens, 95 (46.6%) had empty stomachs, the mean Stomach Fullness Index of the specimens overall being extremely low (0.6). Over a 1-year period, the most important prey of this species were small fishes and decapod crustaceans, the two categories together constituting 73.4% of stomach contents by weight. However, seasonal differences in basic dietary composition were apparent. Fishes were abundant in the diet in May and November, whereas the proportion of hermit crabs in the diet was higher in February compared to other months.

Courtship and spawning behavior of the pygmy grouper, Cephalopholis spiloparaea (Serranidae: Epinephelinae), with notes on C. argus and C. urodeta

Courtship and spawning behavior is described for the grouper Cephalopholis spiloparaea from Rota, Mariana Islands. Daily courtship behavior began late in the afternoon and proceeded until after sunset. Males repeatedly visited females in single-male, multiple-female mating groups during each period and engaged in courtship bouts. Mating was observed only twice, was paired and pelagic. Two congeners, C. argus and C. urodeta, with overlapping geographical distributions, were also examined. Cephalopholis urodeta appeared to have a mating group organization similar to that of C. spiloparaea, with some similarity in courtship behavior. Cephalopholis argus also had a similar mating group organization but differed in courtship behavior. This species' behavior more closely resembled that of similarity-sized Epinephelus spp.