Antipredator responses to invasive lionfish, Pterois volitans: interspecific differences in cue utilization by two coral reef gobies

Understanding prey response to predators and their utilization of sensory cues to assess local predation risk is crucial in determining how predator avoidance strategies affect population demographics. This study examined the antipredator behaviors of two ecologically similar species of Caribbean coral reef fish, Coryphopterus glaucofraenum and Gnatholepis thompsoni, and characterized their responses to different reef predators. In laboratory assays, the two species of gobies were exposed to predator visual cues (native Nassau grouper predator vs. invasive lionfish predator), damage-released chemical cues from gobies, and combinations of these, along with appropriate controls. Behavioral responses indicate that the two prey species differ in their utilization of visual and chemical cues. Visual cues from predators were decisive for both species’ responses, demonstrating their relative importance in the sensory hierarchy, whereas damage-released cues were a source of information only for C. glaucofraenum. Both prey species could distinguish between native and invasive predators and subsequently altered their antipredator responses.     

Bi-directional sex change in a coral-dwelling goby

Bi-directional sex change has recently been reported among obligate coral-dwelling gobies of the genus Gobiodon. However, neither the functional role of this pattern of sex change nor the frequency of sex change in either direction in natural populations is known. We investigated the social structure and pattern of sex change of Gobiodon histrio at Lizard Island on the Great Barrier Reef. The social structure of G. histrio within coral colonies usually consisted of a single juvenile or a heterosexual adult pair. The size of adult social groups was not constrained by coral colony size. In contrast to expectations for pair-forming species, G.␣histrio was primarily a protogynous hermaphrodite. All immature G. histrio were females and sex change from female to male occurred readily when two mature females were placed in a coral colony. In addition, male G. histrio were able to change back to females when two mature males were placed in a coral. Sex change from female to male, however, occurred with over twice the frequency of sex change from male to female. Where two males were placed in a coral colony, heterosexual pairs were most frequently re-established by immigration of females from outside the treatment population. This pattern might be predicted if sex change from male to female is more expensive than sex change from female to male for G. histrio. Where sex change is expensive, movement may be favoured over sex change, particularly where coral densities are high and movement among corals incurs little mortality risk. Received: 10 November 1997 / Accepted after revision: 16 May 1998     

When is a male not a male? Sex recognition and choice in two sex-changing species

For dioecious species, choosing a mate of the same sex can have reproductive costs. For sex-changing animals, however, a lack of sex recognition may not carry a reproductive cost, as pairs that were initially same-sex can become opposite-sex pairs as one partner changes sex. The strength of sex discrimination in sex changers, then, should depend on the duration of mating associations and whether the time of sex change is influenced by social situation (“flexible” sex change). We studied two species of marine snails that change sex from male to female, one with flexible sex change and long-term or permanent mating associations (Crepidula fornicata) and one with short-term pairings and relatively fixed time of sex change (Crepidula convexa), to determine whether either species exhibits sex recognition and whether members of C. convexa show stronger sex discrimination. In laboratory experiments, small males, the choosing animals, were placed with either a male or a female conspecific (no-choice experiments) or given a choice of a male or female (choice experiments). We controlled for shell length in all experiments, as relative size may influence sex change or choice. Males of both species paired more often with females than males, but, as predicted, males of C. convexa showed stronger discrimination: When given a choice, no C. convexa male paired with another male. In contrast, some C. fornicata males always chose other males even when given the choice of a female. These results suggest that sex recognition can be adaptive even for sex changers but demonstrate that the level of sex recognition will depend on other aspects of reproductive behavior.     

Sex change limited by paternal care: a test using four Mediterranean labrid fishes,genus Symphodus

Four species of the Mediterrnean wrasse (genus Symphodus) were investigated under natural conditions near Calvi, Corsica, France, to test the idea that extensive male mating-investment limits the extremes of male reproductive success, and thus reduces selection for protogynous sex change. The four species differ in the extent to which males build nests and care for the eggs, and this sort of paternal care can detract from time spent in mating. In S. ocellatus and S. roissali larger males construct an elaborate nest, ventilate the eggs, and engage in territorial defense. The spawning rates for these males are relatively low and variable due to long periods spent in nest construction and egg tending. They also suffer a large amount of interference from smaller males, which may be due to the predictability of nest location. Sex change appears to be absent. S. tinca males construct only a rudimentary nest, do not ventilate the eggs, and experience much less spawning interference. Large males are relatively more successful in mating in this species, and sex change appears to occasionally occur. The large males of S. melanocercus spawn at a much higher rate than small males, due in part to the fact that they do not construct or defend nests and thus are able to spawn on a daily basis. Sex change appears to be common in this species. Thus, the species that shows the greatest sexual difference in changes of expected fertility with size is also the species that shows the strongest expression of sex change. Studies such as this can begin to indicate the actual costs of changing sex.     

Do protandric pandalid shrimp have environmental sex determination?

Based on demographic analysis of four different temporally enclosed demes of Pandalus borealis in Gullmarsfjorden on the Swedish west coast and published information, I discuss the notion of environmental sex determination in protandric pandalid shrimps as suggested by sex allocation theory. Demographic results showed that age structure and mortality rates varied substantially between four studied periods without noticeable effects on the age of sex change in the fjord populations. The majority of shrimps changed sex at an approximate age of 3 years and became females at an age of 3 to 4 years, however, low proportions (4 to 7%) of 2nd year females (transitional at ca. 1 year) and 3rd year females (5 to 12%) (transitional at ca. 2 years) were present each year. Low proportions of primary females were also found in two of the temporally enclosed demes, in 1985 (9%) and in 1987 (5%). These results do not indicate that yearly variations in age structure, mortality, or frequency of older breeders in the breeding population affect the age of sex change in temporally enclosed fjord demes of this protandric species. An alternative to assuming that the protandric mode of reproduction in pandalid shrimp is combined with environmental sex determination is suggested. Received: 24 September 1996 / Accepted: 6 November 1996     

Gonad morphology, sexual development, and colony composition in the obligate coral-dwelling damselfish Dascyllus aruanus

Gonad morphology and colony composition support the existing supposition that the obligate coral-dwelling damselfish Dascyllus aruanus has a protogynous hermaphroditic sexual pattern. Adults had either an active ovary containing vitellogenic oocytes, an ovotestis, or a spermiated testis and were classified as adult female, hermaphrodite, or adult male, respectively. Among individuals having male function, the testis (or testis portion of the ovotestis) takes the form of an unrestricted spermatogonial lobular testis. Among hermaphrodites having an ovotestis, a small proportion of individuals had a gonad in which both the ovarian and testicular portions were inactive (inactive hermaphrodites), whereas the majority had a predominantly testicular ovotestis that contained spermatozoa (male-active hermaphrodites). The size range of individuals within gonadal classes indicates that all D. aruanus first develop an ovariform gonad. Some individuals then undergo ovarian maturation to become adult females while others develop testicular tissue to form an ovotestis and become male-active hermaphrodites. Subsequently, progressive loss of ovarian tissue results in the development of a secondary testis from an ovotestis with the retention of a residual, afunctional lumen among adult males. The wide size range of individuals having an ovotestis suggests that some hermaphrodites function as adult females before developing testicular tissue while other individuals do not pass through an adult female stage. If this is the case, D. aruanus exhibits a diandric protogynous hermaphroditic sexual pattern. The apparent prolonged retention of an ovotestis with both healthy oocytes and an ovarian-type lumen in a spermiated ovotestis, as well as a functional sex ratio of 1:1 for adult females:adult males plus male-active hermaphrodites also raises the possibility that D. aruanus may be capable of bidirectional sex change during the hermaphroditic stage. Such a capability would be highly adaptive for a species having limited mobility and unpredictable recruitment of new colony members resulting in unpredictable mating opportunities.     

Historical biogeography and speciation in the Creole wrasses (Labridae, <Emphasis Type="Italic">Clepticus</Emphasis>)

We tested whether vicariance or dispersal was the likely source of speciation in the genus Clepticus by evaluating the evolutionary timing of the effect of the mid-Atlantic barrier, which separates C. brasiliensis and C. africanus, and the Amazon barrier, which separates C. parrae and C brasiliensis. Genetic data from three mitochondrial genes and one nuclear gene were used. Mitochondrial genes separated Clepticus into three well supported clades corresponding to the three recognized allopatric morpho-species. All analyses provided consistent support for an initial separation (~9.68 to 1.86 mya; 4.84% sequence divergence) of the Caribbean and South Atlantic lineages, followed by a much more recent divergence (~ 0.60 to 0.12 mya; 0.3% sequence divergence) of the Brazilian and African sister morpho-species. Both these phylogenetic events occurred well after the formation of the two barriers that currently separate those three allopatric populations. The planktonic larval duration of these species (35–49 days) and coastal pelagic habits may have facilitated dispersal by this genus across those dispersal barriers after they formed.     

Fatty acid signature analysis documents the diet of five myctophid fish from the Southern Ocean

Fatty acid (FA) and fatty alcohol (FAlc) compositions of both total lipid and neutral lipid fractions were studied for five myctophid species sampled in Kerguelen waters. Both qualitative and quantitative FA signature analyses were then performed to investigate their diet over longer time scales than the conventional stomach content analysis. Regarding their lipid class, FA and FAlc compositions, the five species could be discriminated into two groups: wax-ester-rich species (Electrona antarctica, Krefftichthys anderssoni) characterised by large amounts of monounsaturated FAs (>73% of total FAs) and triacylglycerol-rich species (Electrona carlsbergi, Gymnoscopelus nicholsi, Protomyctophum bolini) with major amounts of saturated and monounsaturated FAs (>29 and >46% of total FAs, respectively). Qualitative and quantitative FA analyses showed that K. anderssoni mainly preyed upon copepods, E. antarctica upon copepods and more euphausiids and P. bolini and E. carlsbergi mainly upon euphausiids with some copepods, while G. nicholsi had a more diverse diet. This study shows the usefulness of quantitative statistical analysis to determine the diet of Antarctic and sub-Antarctic predators and stresses the need of increasing the lipid and FA analyses of more zooplanktonic and micro-nektonic marine species.     

Phylogeny of Opsanus spp. (Batrachoididae) inferred from multiple mitochondrial-DNA sequences

 Species of the toadfish genus Opsanus are increasingly used as experimental organisms in biomedicine and evolutionary/ecological physiology. Despite their importance, little is known of the phylogenetic relationships among Opsanus species. DNA sequence data for portions of the mitochondrial 12S rRNA, cytochrome oxidase I and cytochrome b genes were generated and analyzed from the four recognized Opsanus species and three outgroup taxa. Results of these analyses indicate an evolutionarily rapid divergence of three lineages within the genus. O. beta and O. pardus were resolved within the same lineage, and could not be distinguished with these mitochondrial sequence data. These data and paleoclimatic theory support a hypothesis of speciation based on the formation of allopatric populations during periods of elevated water temperature in the northern Caribbean. Received: 6 July 1999 / Accepted: 15 March 2000     

Simple molecular method to distinguish the identity of Calanus species (Copepoda: Calanoida) at any developmental stage

Diagnostic morphological characteristics of copepods of the genus Calanus are restricted largely to minor variations in secondary sex characteristics. This presents a persistent problem in the identification of individuals to species level, especially for immature stages. We have developed a simple molecular technique to distinguish between the North Atlantic Calanus species (C. helgolandicus, C. finmarchicus, C. glacialis and C. hyperboreus) at any life stage. Using the polymerase chain-reaction (PCR), the mitochodrial large subunit (16S) ribosomal RNA (rRNA) gene was amplified from individual copepods preserved in ethanol. Subsequent digestion of the amplified products with the restriction enzymes DdeI and VspI, followed by electrophoretic separation in 2% agarose (Metaphor, FMC Ltd), produced a characteristic pattern for each species. The versatility of the method is demonstrated by the unambiguous identification to species of any life stage, from egg to adult, and of individual body parts. Received: 11 May 1998 / Accepted: 5 August 1998     

Purification of multiple vitellogenins in grey mullet (<Emphasis Type="Italic">Mugil cephalus</Emphasis>)

Coralliophila abbreviata (Lamarck) is a corallivorous gastropod that lives and feeds on several species of scleractinian coral in the Western Atlantic and Caribbean. Previous studies of C. abbreviata have revealed that snails on branching acroporid corals are larger and consume more tissue than those on massive and plating corals. To ascertain whether snail life-history and fitness are differentially affected by the coral host, an analysis of the age structure and female reproductive output of snail populations on three coral host taxa (Acropora palmata, Diploria spp., and Montastraea spp.) was conducted at four shallow (2–7 m depth) reef sites off Key Largo, Florida in June through August, 2004. Snails were, on average, almost twice as large on A. palmata than on Diploria spp. and Montastraea spp., averaging 30.3 mm shell length, compared to 17.2 and 17.6 mm, respectively. Brood size increased as a power function with female shell length. Females on A. palmata were significantly larger than females on the other two hosts and, therefore, produced more offspring per female. The number of growth striae on the inner surface of the operculum was used to estimate snail age. Estimates of growth rate were obtained by fitting the Gompertz growth function to size-at-age plots and mortality was estimated using growth parameters and size-frequency data. The data suggest that C. abbreviata inhabiting A. palmata are larger than on alternative hosts due to a combination of a faster growth rate and longer life-span. The species is believed to be a protandrous hermaphrodite. The timing of sex change varied among hosts; snails on A. palmata changed sex later at larger sizes relative to those on the other two hosts. Based on these results, it seems probable that C. abbreviata has developed reaction norms for life-history traits, allowing snails to adjust and maximize fitness in the different environments associated with various coral hosts.     

Phylogeny and biogeography of Sicydiinae (Teleostei: Gobiidae) inferred from mitochondrial and nuclear genes

In the Indo-Pacific area, the Caribbean region and West Africa, insular systems are colonised by particular Gobiids of the Sicydiinae subfamily. These species spawn in freshwater, the free embryos drift downstream to the sea where they undergo a planktonic phase, before returning to rivers to grow and reproduce; an amphidromous lifestyle. These gobies are the biggest contributors to the diversity of fish communities in insular systems and have the highest levels of endemism, yet their phylogeny has not been explored before with molecular data. To understand the phylogeny and the biogeography of this subfamily, sequences from the mitochondrial 16S rDNA and cytochrome oxidase I and from the nuclear rhodopsin gene were obtained for 50 Sicydiinae specimens of seven genera. Our results support the monophyly of the subfamily and of all the genera except Sicyopus, which is polyphyletic. Five major clades were identified within this subfamily. One clade clusters Sicyopterus and Sicydium as sister genera, one contains the genus Stiphodon split into two different groups, two other clades include only Sicyopus (Smilosicyopus) and Cotylopus, respectively, and the last clade groups Akihito, Lentipes and Sicyopus (Sicyopus). As a result, the subgenus Smilosicyopus is elevated herein as a genus. A molecular dating approach helps the interpretation of these phylogenetic results in terms of amphidromy and biogeographical events that have allowed the Sicydiinae to colonise the Indo-Pacific, West African and Caribbean islands.     

Comparative species composition and relative abundance of decapod crustaceans in marine habitats of Panamá

The community structure of the decapod crustacean fauna of 7 tropical, shallowwater, marine habitats (sandy beaches, mangrove swamps and rocky intertidal habitats on both the Pacific and Caribbean coasts of Panama, and Pocillopora damicornis coral habitat of the Bay of Panama) were examined and analyzed for species composition and relative abundances. Collections from the 7 habitats yielded 4361 individuals, representing 236 species. The number of species per habitat was (Pacific, Caribbean): sandy beach (16, 7); mangrove (20, 17); P. damicornis (53); rocky intertidal (78, 67). There were more species represented by more individuals in the Pacific habitats. An index of faunal similarity was calculated for each pair (Pacific-Caribbean) of habitats. This index is the number of ecologically similar congeneric species which occurred in both habitats expressed as a percentage of the total number of species present in the pair of habitats. For the sandy beach communities there were three Pacific species which were similar to three Caribbean species, a similarity of 6/23 or 26%. The index of similarity for the mangrove communities is 54% and for the rocky intertidal communities it is 37%. The P. damicornis community has affinities with the Pacific rocky intertidal community (18%), with that of the Caribbean rocky intertidal (16%) and with that of Indo-West Pacific pocilloporid corals (20%). A few specialized species dominated each of the communities. The habitats and the number of species accounting for over half of the individuals present are (Pacific, Caribbean): sandy beach (1, 1); mangrove (4, 4); P. damicornis (5); and rocky intertidal (3, 6). Most of the species in each community were represented by one or a few individuals.     

Analysis of ribosomal ITS1 sequences indicates a deep divergence between Rhodactis (Cnidaria: Anthozoa: Corallimorpharia) species from the Caribbean and the Indo-Pacific/Red Sea

This paper explores the implications of ribosomal ITS1-sequence analysis for evolutionary relationships between four species of corallimorphs which are morphologically very similar but have distinct distributions. The analyses highlight the unreliability of morphological criteria in establishing systematic relationships amongst tropical corallimorphs. Both parsimony and distance methods of phylogenetic analysis strongly support a deep divergence between the Caribbean species Rhodactics sanctithoma and the three morphologically-related species R. howesii and R. indosinensis from the Indo-Pacific and R. rhodostoma from the Red Sea. The analyses also strongly support a closer relationship between the Red Sea species, R. rhodostoma, and one of the Indo-Pacific species, R. howesii, than between these two and the second Indo-Pacific species, R. indosinensis. The first of these results is presumably a consequence of the closure of the Central American Seaway, the event which led to the separate development of Atlantic and Indo-Pacific coral faunas. However, the lack of detailed distribution data represents a major barrier to reconstructing the evolutionary history of the genus.     

Microstructure of settlement-marks in the otoliths of tropical reef fishes

The morphology and ultrastructure of the otolith settlement-mark was examined in 44 tropical reef-fish species spanning nine families. A classification scheme based on similar otolith characteristics is presented. Three major categories are identified based on changes in increment width and optical qualities of the settlement-mark. Of the 44 species examined, 39 possessed “abrupt” settlement-marks (Type I) characterised by a rapid decrease in increment width (up to 50% reduction) over settlement. Type I settlement-marks were found in all nine families examined. The 39 species spanned the whole range of possible larval durations (Pomacentrus moluccensis, 15 d ± 0 SE; Naso hexacanthus, 91.2 d ± 2.97 SE). Four of the 44 species possessed “zonal” settlement-marks (Type II), featuring a band of increments that are wider than pre-settlement increments. Species in this category are the labrids Corisaygula, Thalassoma bifasciatum, T. lunare and an unidentified acanthurid (Acanthurus sp. 2). One species of acanthurid (N. brevirostris) possessed a “gradual” settlement-mark (Type III), manifest as a gradual decrease in increment width during the settlement period. A possible fourth type was identified from the literature. Gnatholepis thompsoni and Coryphopterus glaucofraenum possessed a settlement-mark with increment widths that increased post-settlement. Available data suggest a poor relationship between the structure of the settlement-mark and the magnitude of metamorphosis (previously reported as internal and external morphological change). Evidence suggests that the increment profile over early development and the increment transitions associated with the settlement event are taxon-specific and may enable late-larval stage fishes to be identified to species level. Received: 21 May 1997 / Accepted: 3 February 1999     

Reproductive patterns of scleractinian corals in the northern Red Sea

The majority of published accounts on scleractinian coral reproduction are from the tropical Pacific and Caribbean, with very little information known about Red Sea species. This report examines variation in reproductive mode in 24 species of hermatypic corals (belonging to seven families) in the Gulf of Eilat, Red Sea. Eighteen species are hermaphroditic broadcasters, two are hermaphroditic brooders and three are gonochoric broadcasters. In the Pocilloporidae, the gonads project into the body cavity, while in the other six families the gonads reside inside the mesenteries. The number of gonads per polyp in broadcasting species follows family or genus lines. Fecundity (eggs per polyp) increases with polyp size. Brooding species usually exhibit one or two gonads per polyp and each gonad contains only one to three oocytes. Oocyte size varies widely and does not relate to mode of reproduction. The largest oocytes (diameter = 450 μm) occur in the brooding coral Alveopora daedalea and in broadcasting species of the genus Acropora (diameter = 420 μm). Gonad morphology and gonochorism versus hermaphroditism appear to be constrained phylogenetically at the family or genus level. Lastly, this report compares the data presented for Red Sea scleractinian species with the data available on scleractinian corals from other geographical regions. Received: 2 February 1993 / Accepted: 9 March 1998     

Latitudinal symbiont zonation in <Emphasis Type="Italic">Stylophora pistillata</Emphasis> from southeast Africa

Studies on latitudinal gradients in Symbiodinium diversity on scleractinian corals are largely restricted to warm-water low latitude locations, and it appears that there is a shift in symbiont distributions with increasing latitude. The Symbiodinium assemblages of high latitude coral communities have largely been undocumented despite occupying an important transitional zone between tropical and temperate regions. Using a combination of the internal transcribed spacer region 2 (ITS2) and denaturing gradient gel electrophoresis (DGGE), we assessed the cladal and subcladal variability of Symbiodinium in the widely distributed species Stylophora pistillata along a latitudinal transect in southeast African waters which extended into high latitude locations. All colonies examined belonged to clade C. Six unique ITS2-DGGE banding profiles (designated C_spa to C_spf) were observed, which showed a latitudinal distribution from north to south, most likely a result of a gradient in water temperature and irradiance driven by riverine input in the southern regions. Sequence analysis revealed that all sequences except one did not match previously identified clade C sub-types, probably due to the lack of regional information in the Western Indian Ocean when compared to the Caribbean and Pacific. This study further supports the applicability of ITS2-DGGE in studies on Symbiodinium diversity, and highlights that potentially ecologically informative biogeographic patterns may be overlooked when only cladal designations are employed.     

Distribution of common dolphins (Delphinus spp.) in the western Atlantic Ocean: a critical re-examination

Due to indications that misidentification (largely confusion among dolphins of the genera Delphinus and Stenella) in the past had led to erroneous assumptions of distribution of the two species of common dolphins (Delphinus delphis and D. capensis) in the western Atlantic Ocean, we conducted a critical re-examination of records of the genus Delphinus from this region. We compiled 460 ‘plottable’ records, required support for confirmation of genus and species identifications, and found many records lacking (and some clearly misidentified). When we plotted only the valid records (n = 364), we found evidence of populations in only three areas, and apparent absence throughout much of the tropical/subtropical regions. Off the east coast of the US and Canada, D. delphis is found from the Georgia/South Carolina border (32°N) north to about 47–50°N off Newfoundland. Since the 1960s, they have apparently been absent from Florida waters. There is no evidence that dolphins of the genus occur in the Gulf of Mexico. Reports of common dolphins from most of the Caribbean Basin are also rejected, and the only place in that region where they are confirmed to occur is off central-eastern Venezuela (a coastal D. capensis population). Off eastern South America, common dolphins appear to be restricted to south of 20°S. There is a coastal long-beaked population found in the South Brazil Bight, and one or more short-beaked populations south and offshore of this (ranging south to at least northern Argentina). The results are very different from commonly-accepted patterns of distribution for the genus in the Atlantic. Most areas of distribution coincide with moderate to strong upwelling and common dolphins appear to avoid warm, tropical waters. This study shows that great care must be taken in identification of similar-appearing long-beaked delphinids, and that uncritical acceptance of records at face value can lead to incorrect assumptions about the ranges of the species involved.     

Follicovitellosum indicum,a new trematode,found in the fish Belone belone

A new trematode, collected in 1971 from Ratnagiri, India, is described as Follicovitellosum indicum sp. nov. A new subfamily, Follicovitellotrematinae is created within the family Zoogonidae Odhner, 1911, to receive the new genus Follicovitellosum, with its genotype F. indicum. The new species is characterized by the follicularized nature of its ovary; the ovarian follicles are posttesticular. The vitellarium is further divided into several follicles which are largely in the pre-ovarian zone, but post-acetabular and posttesticular in location.     

Observations on the reproductive cycles of Monodonta lineata,Gibbula umbilicalis and G. cineraria

Monthly samples of gonads of 3 common species of intertidal trochids, Monodonta lineata (da Costa), Gibbula umbilicalis (da Costa) and G. cineraria (L.) were fixed for examination by light microscopy. Numbers and proportions of immature and mature oocytes in sections of ovaries were determined. In M. lineata and G. umbilicalis, the annual reproductive cycles were very similar, the testis and ovary of both species being empty brown structures from September to January/February, when gametogenesis began and the gonads began to swell and turn green in both sexes. As ripening continued, the ovary remained green in G. umbilicalis, but in M. lineata turned greygreen by the end of May. The testis of both species changed, to yellowish in G. umbilicalis and creamy-pink in M. lineata. Spawning occurred throughout summer and early autumn, and the gonads reverted to their former empty state. These changes were matched by the increase and subsequent decrease in proportion of ripe oocytes in the gonad. Some ripe oocytes are not shed during the spawning season, but no evidence of cytolysis of such oocytes was found. In G. cineraria, in contrast, the ovary remained green and swollen and the testis remained creamy-white and packed with sperm throughout the year. The proportion of ripe to unripe oocytes in the ovary fluctuated for the entire sampling period, and did not indicate the time of spawning. In the testis of all three species, spermatogonia were rarely seen, and spermatid stages were uncommon.