Sociality in <Emphasis Type="Italic">Euglossa</Emphasis> (<Emphasis Type="Italic">Euglossa</Emphasis>) <Emphasis Type="Italic">viridissima</Emphasis> Friese (Hymenoptera,Apidae, Euglossini)

Euglossa viridissima is an orchid bee that forms both solitary and multiple female nests, making it a suitable species for the study of factors leading to diverse degrees of sociality in Euglossines. We conducted observations in eight reused nests (where a first generation of bees had been produced) kept in artificial boxes from the Yucatan Peninsula, Mexico. Five nests were reused (reactivated) by a single female (SFN), two nests reused by a mother and one daughter (MFN1) and one nest reused by the mother and two daughters (MFN2). No single nest was reactivated by unrelated females. The number of foraging trips, their duration and the duration of cell provisioning was not different between SFN and MFN. The overall production of cells per female was not different either between both types of nest. However, in MFN although all females did lay eggs, there was a reproductive skew in favor of the mother (95 and 45% of the brood produced in MFN1 and MFN2 respectively). She showed reproductive control of her daughters through oophagy and displaying threatening behavior when the daughters tried to open a cell where she had laid an egg. Brood losses to parasites (Anthrax sp. (Bom-byliidae) and Hoplostelis bivittata (Megachilidae)) were only found in SFN which possibly reflects and advantage of MFN in this respect. Our results coupled with other studies in Euglossa, reveal that a wide range of social behaviors occur in this genus, from solitary and communal to primitive reproductive division of labor. Multiple factors involving different levels of pressure imposed by food availability and parasites may favor such a diverse range of nesting behaviors. Interestingly, female associations in E. viridissima seem a result of kin selection that is enforced by coercion from mother females on their daughters. More studies are needed to shed light upon the social organization of Euglossa and other Euglossines and on their phylogenetic relationships in order to trace the origins of eusociality in Apidae. Received 12 February 2008; revised 25 June 2008; accepted 17 July 2008.     

Sperm allocation pattern during a reproductive season in the copulating marine cottoid species, <Emphasis Type="Italic">Alcichthys alcicornis</Emphasis>

The sperm allocation pattern of a copulating marine cottid fish, Alcichthys alcicornis, was investigated. A total of 86 mating events using six males were conducted in aquarium tanks over 10 days, and in 36 of them, spermatozoa were collected using a false copulation method. Males released 3–8 × 10⁸ spermatozoa in early events, with the number decreasing gradually during subsequent mating events. This sperm allocation was represented as an “early investment and tapering” pattern. It was discussed why males have significantly higher sperm release in early spawning events. The reproductive behavior consists of spawning and subsequent copulation. Spermatozoa have the ability to fertilize eggs from multiple clutches, and in earlier produced clutches the level of sperm competition should be relatively low. In addition, if early spawn happens to be the first spawn with a female, spermatozoa that are released into the water column after spawning are responsible for fertilizing the female’s first clutch. The probability of this occurring should decrease dramatically as the season progresses, due to the highly synchronous seasonal spawning of females. All of these factors should select for high sperm numbers in early ejaculates. Based on such reproductive ecology of A. alcicornis we hypothesize that this sperm allocation pattern is an adaptive reproductive strategy in response to egg availability and sperm competition occurring within the ovarian cavity.     

Fish-egg predation by the small clingfish <Emphasis Type="Italic">Pherallodichthys meshimaensis</Emphasis>(Gobiesocidae) on the shallow reefs of Kuchierabu-jima Island,southern Japan

Synopsis We observed predation of demersal fish eggs by the clingfish Pherallodichthys meshimaensis on the shallow reefs of Kuchierabu-jima Island, southern Japan. The processes of egg predation varied with the target species. For targeting of eggs of the combtooth blenny Istiblennius edentulus, up to 65 individuals of the clingfish gathered around the I. edentulus nest hole. Some individuals succeeded in intruding into the hole and fed on eggs while the egg-guarding male of I. edentulus temporarily left the nest. For targeting of eggs of the triplefin blenny Helcogramma obtusirostris, solitary clingfish individuals closely approached spawning females of H. obtusirostris at nests on open surfaces of rocks. Most clingfish contained only fish eggs in their diets, and these fish-egg eaters had larger body sizes than individuals that mainly fed on harpacticoid crustacea. Thus, P. meshimaensis may change its feeding habits when growing to an obligate fish-egg eater targeting demersal egg spawners.     

Spatial aspects of reproduction in buffalo sculpin,Enophrys hison

Synopsis The spatial distribution and parental care of demersal egg masses of buffalo sculpin (Enophrys bison) were studied at 11 areas in Puget Sound, Washington, during 1972–1973. Adult buffalo sculpin inhabited rock and rock-sand habitats at depths from the intertidal to minus 20 m throughout the year, but 84% of all spawn clusters were found at depths between –1 m and +1 m within localized rocky areas. Areas used for spawning were exposed to strong tidal currents and other water movements. A single male fish guarded and fanned spawn, but eggs were temporarily deserted when less than about 1 m of water covered the spawning site. The cyclical nature of male desertion, behavior of spawn predators, and spawn mortality due to physical factors while emergent suggest several possible advantages to low intertidal spawning. These advantages include spatial and temporal escape from marine predators by embryos, time for the tending parent to forage, and optimal physical conditions for embryonic development.     

Detection and biocontrol potential of <Emphasis Type="Italic">Verticillium leptobactrum</Emphasis> parasitizing <Emphasis Type="Italic">Meloidogyne</Emphasis> spp.

Three isolates of Verticillium leptobactrum proceeding from egg masses of root-knot nematodes (RKN) Meloidogyne spp. and soil samples collected in Tunisia were evaluated against second-stage juveniles (J2) and eggs of M. incognita, to determine the fungus biocontrol potential. In vitro tests showed that V. leptobactrum is an efficient nematode parasite. The fungus also colonized egg masses and parasitized hatching J2. In a greenhouse assay with tomato plants parasitized by M. incognita and M. javanica, V. leptobactrum was compared with isolates of Pochonia chlamydosporia and Monacrosporium sp., introducing the propagules into nematode-free or naturally infested soils. The V. leptobactrum isolates were active in RKN biocontrol, improving plants growth with a significant increase of tomato roots length, lower J2 numbers in soil or egg masses, as well as higher egg mortalities. In a second assay with M. javanica, treatments with three V. leptobactrum isolates reduced egg masses on roots as well as the density of J2 and the number of galls. To evaluate the fungus capability to colonize egg masses a nested Real-time polymerase chain reaction (PCR) assay, based on a molecular beacon probe was used to assess its presence. The probe was designed on a V. leptobactrum ITS region, previously sequenced. This method allowed detection of V. leptobactrum from egg masses, allowing quantitative DNA and fungal biomass estimations.     

Why egg-caring males of Isaza (<Emphasis Type="Italic">Gymnogobius isaza</Emphasis>, Gobiidae) refuse additional females: preliminary field observations

Like many other gobies, males of the Isaza goby, Gymnogobius isaza endemic to Lake Biwa, Japan, conduct parental care of eggs at nests, and females are likely to choose mates while visiting nests. The reproductive strategy should induce polygyny, but Isaza males never accept additional females in one breeding cycle. Sampling data of broods indicated that the egg mass areas were much smaller than the nest sizes, suggesting that nest size is not the limiting factor in obtaining further eggs from additional females. The brood size greatly decreased as the duration of care progressed. Few individuals including caring males ate eggs, and heterospecific egg predators were rarely observed. Sixty percent of egg masses at the middle stages of egg development were infected with aquatic fungi, some being covered with a fungus mat that drastically reduced survivorship. Infected egg masses contained more eggs than non-infected ones at the same stage, indicating that large egg masses are prone to be frequently destroyed by fungi. It is likely that the activity of parental males is lowered during the long care periods at low water temperature in early spring. Such lowered activity of caring males might be responsible for infections in large broods that would have needed more care. We propose the hypothesis that male rejection of additional females may be related to optimal brood size, which will be less susceptible to fungus infection and produce more hatching young than otherwise. This hypothesis will explain not only male avoidance of additional females but also some unique reproductive behaviors of this fish such as some females spawning of a portion of of the mature eggs in one nest.     

The fitness of the Brazilian damsel <Emphasis Type="Italic">Stegastes fuscus</Emphasis> is increased by sharing the territory with the dusky grouper <Emphasis Type="Italic">Epinephelus marginatus</Emphasis>

Stegastes fuscus and Epinephelus marginatus are known for co-habiting shelters. The damselfish S. fuscus uses the territory for nesting and must protect its eggs from grazers; the grouper E. marginatus is an omnivorous sit-and-wait predator. This study aims to evaluate the effect of juvenile groupers on the reproductive success of the Brazilian damsel. Twenty-five hours of underwater observations were done in São Sebastião and Ilhabela, Northern shore of São Paulo, Brazil. Fitness increase was measured by the egg-clutch area and number of contributing females in 130 nests shared by groupers and another 130 where damselfishes stood alone. An egg predator crab was placed into the damselfish territory, and behavioural responses during 2 min were recorded for nests with or without E. marginatus, 80 replicates each. Nests shared by the dusky groupers had more eggs and received eggs from more females too. While fathers who were alone in the territory had to deal with the egg predator crab, in shared nests, the grouper would take care of the intruder, sometimes feeding on it. Therefore, the Brazilian damsel may benefit from the presence of the dusky grouper by increasing the fitness and diminishing the costs of parental care.     

Interspecific territoriality in males of the tube blenny <Emphasis Type="Italic">Neoclinus bryope</Emphasis> (Actinopterygii: Chaenopsidae)

Territoriality was investigated in the tube blenny Neoclinus bryope (Actinopterygii: Chaenopsidae) at rocky intertidal areas of Banda Beach, Tateyama Bay, central Japan. Males used small holes as spawning nests, usually staying at the nest and maintaining the area while showing exclusive behaviors. Their home ranges were limited to areas within 30 cm distance from the nest for over 2 months. Four heterospecific fishes were threatened when they approached to within 6–14 cm of the nest holes, and two species of carnivorous snails were removed at points 0–30 cm from the nest entrance. There were no significant differences between the distances from the nest entrances to the points defended against fish and those used for foraging. As the four heterospecific species have similar feeding habits to those of N. bryope, the area defended against fishes may function as a foraging territory. At 24 h following the removal of nest owners, carnivorous snails had gathered to actively prey on eggs, indicating that the area defended against snails may function as a territory for protection against egg predators. Although the positions of females where males started courtship displays were significantly farther than the foraging points and the positions of threatened fishes, males displayed no territoriality against conspecific males. The fact that males did not leave the nest hole during the courtship suggests that it may be costly to maintain a courtship territory. These results show that males of tube blenny maintain territories for egg guarding and for protecting food resources around their nest holes in the spawning season.     

Biology of <Emphasis Type="Italic">Lasioglossum</Emphasis> (<Emphasis Type="Italic">L.</Emphasis>) <Emphasis Type="Italic">majus</Emphasis> (Hymenoptera: Halictidae), a largely solitary sweat bee with behavioural adaptations to communality

Within the bee family Halictidae there have been three origins of sociality. Although detection of origins and reversal from sociality requires phylogenetic studies, at a behavioural level a predisposition to sociality can be detected by analysis of intra-specific interactions. We studied aspects of nesting biology and behavioural interactions in Lasioglossum (Lasioglossum) majus, a poorly known halictine inhabiting temperate regions of Europe, which is suspected to be solitary. Nests were found to be largely used by one female, but some were shared by more than one individual. These few nests, whose entrances were very close to each other, were found to be connected underground. A few individuals were observed to enter in a nest where a female was waiting, behaving as a guard and allowing the incoming bee to enter the nest. By use of circle-tube experiments, the behavioural repertoire exhibited by females during encounters was assessed. Levels of withdrawal and cooperative events were comparable with those observed in other solitary nesting species, but aggressive events were very rare, as in several observed communal species. We conclude that L. (L.) majus females, despite general solitary nesting, possess behavioural components enabling them to adopt, probably in high nest-density areas, nest-sharing strategies. A similar kind of local social polymorphism has been observed in two other species of the subgenus Lasioglossum, but these are the first data available on a European species and the first record of subterranean connections among nests of halictid bees.     

Consumers of sea urchins,<Emphasis Type="Italic"> Paracentrotus lividus</Emphasis> and<Emphasis Type="Italic"> Arbacia lixula</Emphasis>, in shallow Mediterranean rocky reefs

Underwater observations on fish and asteroid consumers (i.e. predators and scavengers) of sea urchins, Paracentrotus lividus and Arbacia lixula, were carried out at several locations in shallow Mediterranean rocky reefs. Observations conducted in the marine reserve of Torre Guaceto (Adriatic Sea) revealed that sparid fishes, Diplodus sargus and D. vulgaris, are the main fish predators of small (<1 cm in test diameter) and medium (1–4 cm) sea urchins, whereas the labrids Coris julis and Thalassoma pavo preyed only upon small sea urchins. Large D. sargus were able to prey upon small and medium, and occasionally large (>4 cm) sea urchins, whereas medium and small Diplodus preyed mainly upon small sea urchins. The number of sea urchins preyed upon by fishes was negatively related to sea urchin size for both species. P. lividus appeared to be subject to higher predation levels than A. lixula. The scavenger guild comprised 11 fish species, with D. sargus, D. vulgaris, Coris julis and Chromis chromis accounting for about 80% of scavenger fishes. Observations performed at several locations in the Mediterranean on the predatory asteroid Marthasterias glacialis revealed that only 3% of the detected individuals were preying upon sea urchins. Due to the importance of sea urchins for assemblage structure and functioning of Mediterranean rocky reef ecosystems, these results may have also important implications for management of fishing activities.Communicated by H.-D. Franke     

Spawning strategy in Atlantic bobtail squid <Emphasis Type="Italic">Sepiola atlantica</Emphasis> (Cephalopoda: Sepiolidae)

This study aimed to determine the spawning strategy in the Atlantic bobtail squid Sepiola atlantica, in order to add new information to the knowledge of its reproductive strategy. A total of 12 females that spawned in aquaria were examined. Characteristics of the reproductive traits and egg clutches were similar to those of other known Sepiolidae. Clutch size varied from 31 up to 115 eggs. Females of this species had incorporated up to 1.58 times of their body weight into laid eggs. The size of laid eggs showed a positive correlation with maternal body size, supporting the idea that female size is a determinant of egg size. Our data suggest that S. atlantica is an intermittent terminal spawner, and that its spawning strategy comprises group-synchronous ovary maturation, multiple egg laying, and deposition of egg clutches in different locations. The obtained data provide insights for future comparative studies on reproductive allocation.     

Semi-lunar spawning cycle and mating tactics in the marine goby <Emphasis Type="Italic">Asterropteryx semipunctata</Emphasis>

The reproductive behaviors of the marine goby Asterropteryx semipunctata were studied at Sakurajima, Kagoshima, Japan. Spawning occurred from late June to early October with a peak at 3–4 days after the full and new moon. This semi-lunar cycle might be advantageous to reducing nest-egg mortality but may not to larvae dispersion. Large males maintained spawning nests, and females spawned a whole clutch at a nest but with multiple males during a season. Females were less likely to be choosy due probably to a predation risk and/or nesting male shortage. Smaller males adopted sneaking tactics, and some of them became nesting males.     

Oviposition Sites of the Cypress Seed Bug <Emphasis Type="Italic">Orsillus maculatus</Emphasis> and Response of the Egg Parasitoid <Emphasis Type="Italic">Telenomus</Emphasis> gr. <Emphasis Type="Italic">Floridanus</Emphasis>

Phytophagous insects have many strategies to escape parasitoids, for example by hiding eggs into plant tissues, but oviposition in holes made by another insect is rather scarce. The cypress seed bug Orsillus maculatus Fieber (Heteroptera: Lygaeidae) is strictly dependent on the availability of cones of Cupressus sempervirens L. to oviposit. Females lay eggs either in exit holes cut through the cone scale by emerging adults of the cypress seed chalcid, Megastigmus wachtli Seitner (Hymenoptera: Torymidae), or on the inner side of scales of partly open cones. A recently discovered egg parasitoid belonging to the genus Telenomus has been shown to attack bug eggs in both oviposition sites. In this paper we investigated the parasitoid performance according to oviposition sites. Field samplings were conducted in two evergreen cypress orchards located in the south of France. The distribution and condition of the egg patches were compared between the two locations and oviposition sites. Seed bugs preferred to oviposit in emergence holes of M. wachtli, and parasitoid performance was higher in eggs laid on cone scales. The chalcid emergence holes seemed to ensure bug eggs with enemy-free space. Oviposition site selection could be an adaptive strategy to escape parasitoid attack.     

Effects of the pathogenic haemoflagellate, <Emphasis Type="Italic">Cryptobia salmositica</Emphasis> on brood fish, <Emphasis Type="Italic">Oncorhynchus mykiss</Emphasis>

Sexually matured rainbow trout, Oncorhynchus mykiss, were experimentally infected with the pathogenic Cryptobia salmositica. Spawning female trout were more susceptible to cryptobiosis than sexually mature males. Most infected females (seven of nine) with eggs died before or shortly after spawning while all (nine) infected males survived the disease. Also, none of the uninfected females died. Males initially increased milt production and sperm concentration; however semen production declined as the disease progressed. Sperm from infected males fertilized more eggs than those from non-infected males. No differences in weight and survival were observed between progeny of infected and uninfected males.     

Culturable and VBNC <Emphasis Type="Italic">Vibrio cholerae</Emphasis>: Interactions with Chironomid Egg Masses and Their Bacterial Population

Vibrio cholerae, the etiologic agent of cholera, is autochthonous to various aquatic environments. Recently, it was found that chironomid (nonbiting midges) egg masses serve as a reservoir for the cholera bacterium and that flying chironomid adults are possible windborne carriers of V. cholerae non-O1 non-O139. Chironomids are the most widely distributed insect in freshwater. Females deposit egg masses at the water's edge, and each egg mass contains eggs embedded in a gelatinous matrix. Hemagglutinin/protease, an extracellular enzyme of V. cholerae, was found to degrade chironomid egg masses and to prevent them from hatching. In a yearly survey, chironomid populations and the V. cholerae in their egg masses followed phenological succession and interaction of host–pathogen population dynamics. In this report, it is shown via FISH technique that most of the V. cholerae inhabiting the egg mass are in the viable but nonculturable (VBNC) state. The diversity of culturable bacteria from chironomid egg masses collected from two freshwater habitats was determined. In addition to V. cholerae, representatives of the following genera were isolated: Acinetobacter, Aeromonas, Klebsiella, Shewanella, Pseudomonas, Paracoccus, Exiguobacterium, and unidentified bacteria. Three important human pathogens, Aeromonas veronii, A. caviae, and A. hydrophila, were isolated from chironomid egg masses, indicating that chironomid egg masses may be a natural reservoir for pathogenic Aeromonas species in addition to V. cholerae. All isolates of V. cholerae were capable of degrading chironomid egg masses. This may help explain their host–pathogen relationship with chironomids. In contrast, almost none of the other bacteria that were isolated from the egg masses possessed this ability. Studying the interaction between chironomid egg masses, the bacteria inhabiting them, and V. cholerae could contribute to our understanding of the nature of the V. cholerae–egg mass interactions.     

Antifungal skin bacteria,embryonic survival,and communal nesting in four-toed salamanders, <Emphasis Type="Italic">Hemidactylium scutatum</Emphasis>

We examined a novel hypothesis for the maintenance of communal nesting in the salamander, Hemidactylium scutatum, namely that communal nests are more likely than solitary nests to be associated with cutaneous antifungal bacteria, which can inhibit fungal infections of embryos. A communal nest contains eggs of two or more females of the same species. The nesting behavior of H. scutatum females and survival of embryos were determined by frequent nest surveys at three ponds. For communal nests, embryonic survival tended to be higher and catastrophic nest failure was lower. Pure bacterial cultures of resident species were obtained from the salamanders’ skins by swabbing and tested against a fungal pathogen of embryos (Mariannaea sp.) in laboratory assays. We found that 27% of females had skin bacteria inhibitory to Mariannaea sp. Communal nests were more likely to have at least one female with antifungal bacteria than were solitary nests. Using a culture-independent assay (denaturing gradient gel electrophoresis of 16S rRNA gene fragments), we found that bacterial species on females and embryos were more similar to each other than they were to bacterial species found in soil within the nest, suggesting that females transmitted skin bacteria to embryos. The presence of anti-Mariannaea skin bacteria identified from the laboratory assays did not prevent fungal presence in field nests. However, once a nest was visibly infected with fungi, presence of anti-Mariannaea bacteria was positively correlated with survival of embryos. Microbe transmission is usually thought to be a cost of group living, but communal nesting in H. scutatum may facilitate the transmission of antifungal bacteria to embryos.     

Comparison between community structures of fishes in <Emphasis Type="Italic">Enhalus acoroides</Emphasis>- and <Emphasis Type="Italic">Thalassia hemprichii</Emphasis>-dominated seagrass beds on fringing coral reefs in the Ryukyu Islands,Japan

To clarify differences in community structures and habitat utilization patterns of fishes in Enhalus acoroides- and Thalassia hemprichii-dominated seagrass beds on fringing coral reefs, visual censuses were conducted at Iriomote and Ishigaki islands, southern Japan. The numbers of fish species and individuals were significantly higher in the E. acoroides bed than in the T. hemprichii bed, although the 15 most dominant fishes in each seagrass bed were similar. Cluster and ordination analyses based on the number of individuals of each fish species also demonstrated that fish community structures were similar in the two seagrass beds. Species and individual numbers of coral reef fishes which utilized the seagrass beds numbered less than about 15% of whole coral reef fish numbers, although they comprised about half of the seagrass bed fishes. Of the 15 most dominant species, 5 occurred only in the two seagrass beds, including seagrass feeders. Ten other species were reef species, their habitat utilization patterns not differing greatly between the two seagrass beds. Some reef species, such as Lethrinus atkinsoni and L. obsoletus, showed ontogenetic habitat shifts with growth, from the seagrass beds to the coral areas. These results indicate that community structures and habitat utilization patterns of fishes were similar between E. acoroides- and T. hemprichii-dominated seagrass beds, whereas many coral reef fishes hardly utilized the seagrass beds.     

Influence of diet on the predation rate of <Emphasis Type="Italic">Orius laevigatus</Emphasis> on <Emphasis Type="Italic">Frankliniella occidentalis</Emphasis>

The predation rate of fifth instars and female adults of Orius laevigatus (Fieber) fed honeybee pollen, Ephestia kuehniella Zeller eggs or an egg yolk based artificial diet on second instars of the western flower thrips Frankliniella occidentalis (Pergande) was examined in the laboratory. Predation rate of both fifth instars and female adults was not influenced by their diet. Despite a lower body weight, O. laevigatus reared on artificial diet or pollen killed as many prey as their peers reared on E. kuehniella eggs, suggesting that body weight is not a reliable predictor of predation rate. The use of non-prey foods for O. laevigatus for mass production or as a supplementary food to sustain its populations in the field when prey are scarce is discussed.     

Observations of a wild polar bear (<Emphasis Type="Italic">Ursus maritimus</Emphasis>) successfully fishing Arctic charr (<Emphasis Type="Italic">Salvelinus alpinus</Emphasis>) and Fourhorn sculpin (<Emphasis Type="Italic">Myoxocephalus quadricornis</Emphasis>)

Polar bears, Ursus maritimus, throughout their range, are nutritionally dependent on ringed (Phoca hispida) and bearded seals (Erignathus barbatus), which are predominantly caught on the sea ice. Other marine prey species are caught and consumed, but less frequently. As the annual sea ice retreats, polar bears throughout their range are forced ashore, where they mostly live off their stored adipose tissue. However, while land-bound they have been observed catching birds and terrestrial mammals. Although polar bears evolved from brown bears (U. arctos), direct observations of polar bears diving for and catching fish have not been reported. Here, we document observations of a young male polar bear catching Arctic charr (Salvelinus alpinus) and Fourhorn sculpin (Myoxocephalus quadricornis) by diving in Creswell Bay, Nunavut. We recorded six search bouts, where six fish were caught during dives, which were preceded by a snorkel. The average dive and snorkel length was (mean ± SD) 13 ± 5 and 6 ± 2 s, respectively.     

Aggregations of <Emphasis Type="Italic">Plectropomus areolatus</Emphasis> and <Emphasis Type="Italic">Epinephelus fuscoguttatus</Emphasis> (groupers,Serranidae) in the Komodo National Park,Indonesia: Monitoring and Implications for Management

Synopsis We identify fishery management implications from a long-term monitoring program focusing on spawning aggregations of high valued reef fish in Komodo National Park (KNP), Eastern Indonesia. Management objectives of KNP are not only to protect biodiversity, but also to conserve spawning stocks of high-valued commercial species for the replenishment of surrounding fishing grounds. We monitored two sites twice monthly over five years for two species of grouper, Epinephelus fuscoguttatus and Plectropomus areolatus. One site had an aggregation of both E. fuscoguttatus and P. areolatus, whereas the other site contained an aggregation of P. areolatus only. Over the five years monitoring period, aggregations typically formed during each full moon between September and February. Additionally, P. areolatus occasionally aggregated during new moons between April and July. We observed spawning only once, but because formation of aggregations were correlated to a higher incidence of behavior and signs indicative of reproduction and because most fish present were adults, it is likely that the formation of aggregations was associated with spawning. Over the five years monitoring period there was a reduction in mean fish size of up to 8 cm for P. areolatus, and a reduction in numbers of aggregating E. fuscoguttatus. Despite limited protection initiated in 2001, both sites are still heavily fished by local artisanal fishers. Because the observed reductions in size and in numbers could be caused by fishing pressure, managers should follow the precautionary principle by putting additional protective management in place. Since both species are relatively long-lived, at least five years of continued monitoring may be necessary to determine the outcome of management intervention. The variability in timing of aggregation in respect to season and moon phase in P. areolatus indicates that long-term monitoring must cover the entire year and both moon phases.