Pair Spawning Research Articles

On the spawning behavior and spawning cycles of eight surgeonfishes (Acanthuridae) from the Indo-Pacific

Surgeonfish spawning was observed at Palau, Lizard Island, Escape Reef (all Pacific Ocean) and Aldabra (Indian Ocean). Seven species, all fairly exclusively benthic feeding, defended feeding territories to some extent, and some of them formed territorial groups composed of 1 male + ≥ 1 female. One other species ate both benthic algae and zooplankton, and both sexes appeared to be nonterritorial, except that males defended temporary spawning territories. The primary spawning rhythm appeared to be a restriction of spawning to part of the day. Ebb-tide spawning rhythms were evident where distinct tidal currents flowed on and off a reef: at one such site (Palau), a secondary tidal rhythm of spawning overlaid and combined with the primary rhythm to produce an apparent semi-lunar rhythm of spawning. Peaks of spawning of three Palauan species were on days when tidal heights/amplitudes were either less than or no different from the mean. Fishes that lived in intertidal areas (including some from heterosexual territorial groups) migrated to and massed and spawned at the intertidal/subtidal interface. Some fishes spawned in pairs, either in their (intertidal and subtidal) feeding territories or in temporary spawning territories at the reef edge. Many that migrated to the reef edge were (temporarily) nonterritorial there, and spawned in groups [I female (sometimes more?) + many males]. Predatory fishes and zooplanktivorous fishes attacked spawning fishes and fed on fresh ova. At Palau, egg predators attacked group, rather than pair spawnings. Pulses of massed group spawning may reduce the rate of egg predation per group spawning. Two different types of color change by both sexes were associated with the two basically different patterns of spawning — in pairs and in groups.

The Organization of the Pre-Spawning Behaviour in the Cichlid Fish Aequidens Portalegrensis (Hensel)

This study was aimed at obtaining insight into: a) how the communicative activities carried out by this substrate laying cichlid fish during the several days lasting pre-spawning period, function in facilitating pair formation, spawning and broodcare, and b) how the behavioural mechanism controlling the performance of these activities is structured. Both sexes use largely the same activities. The causational problems were primarily approached through statistical analysis of quantitative observations, regularly made on interacting males and females between their first confrontation and spawning. On the basis of the temporal association between the various activities, the latter could be classed into three groups, or clusters, which became successively dominant in the course of the pre-spawning period. On the ground of further observations, and on the results of experiments, a closer specification of the factors underlying these clusters was attempted. It was concluded that they are primarily due to internal factors or interactions between such factors, which can however be activated by specific external stimuli. The cluster appearing in the earliest phase of the encounter is simultaneously controlled by tendencies to attack and to escape; this behaviour subserves the defense of the territory. Absence of overt aggression in the response of the female appeases the agonistic behaviour of the male and causes the appearance of behaviour of the second cluster. In the control of this cluster a sexual system is involved beside the agonistic systems. Most of the activities of this cluster are instrumental in preparing a nest site; moreover their performance is likely to have a priming effect on the sexual factor. When this factor has become dominant over the agonistic ones, the fishes concentrate their behaviour on a hard substrate and the activities of the third cluster appear, culminating in oviposition and fertilizing.

Dualistic spawning behaviour of the cunner, Tautogolabrus adspersus (Pisces: Labridae), in Bonne Bay, Newfoundland

Group spawning and pair spawning cunners, Tautogolabrus adspersus, were studied at Bonne Bay, Newfoundland. This is the first recorded occurrence of both types of spawning behaviour of this species at a single location. Group spawning occurred within aggregations of 30 to > 150 fish. Cunners in group spawning aggregations ranged in length from 80 to 180 mm. Those with brown phase colouration outnumbered those with male nuptial (blue phase) colouration by at least 3:1. All courtship was initiated by males with nuptial colouration, but some brown-phase males participated in group spawnings. Pair spawning involved territorial males and was observed within 5 m of an aggregation in which group spawning was occurring. Territorial males were larger than 200 mm and had nuptial colouration. They were not observed where small (< 180 mm) cunners were most abundant. Group spawning occurred in the afternoon, being most frequent between 1800 and 1900 hours.

Pair Spawning in the Princess Parrotfish, Scarus taeniopterus

Pair Spawning in the Princess Parrotfish, Scarus taeniopterus

Correlates between number of mates, shelter availability and reproductive behavior in the Tautog Tautoga onitis

Earlier studies on reproductive behavior of the tautog Tautoga onitis under laboratory conditions indicated that differences in courtship and spawning behavior were apparently related to the number of males attempting to spawn with a female. It had also been conjectured that certain ecological factors such as availability and distribution of food and shelter would play a role in the establishment of territoriality and defense of a female, indirectly influencing courtship activities and the resultant spawning mode. In the present work we have examined this question more closely by varying the number of males, females and amount of shelter available. Regardless of the social situation, in every instance single males, through aggression, attempted to limit access to a female and pair spawn. The degree to which this succeeded depended on the male's place in the dominance hierarchy, the number of males in proximity which were actively attempting to spawn and the availability of shelter. Courtship activity of the female was influenced by the amount of male attention. When attention was high, the nuptial shading of the female never developed maximally. On the other hand, when male attention was low, the female showed progressive and maximal shading development to attract males. The significance of the findings is discussed.

Spawning behaviour of the freshwater catfish Tandanus tandanus (Plotosidae)

Details of individual behaviour patterns in direct pair spawning activities are described and illustrated. Aspects of reproductive behaviour and spawning are briefly discussed.

Field observations on the reproductive behaviour of the cunner, Tautogolabrus adspersus (Walbaum), in Newfoundland

Courtship behaviour and pair spawning of the cunner, Tautogolabrus adspersus (Walbaum) were observed in Conception Bay, Newfoundland, during midsummer of 1977 and 1978. Courtship displays were recorded between 0600 and 2100 hours and spawns between 1300 and 2100 hours. The frequency of both courtship behaviour and spawns varied with the time of day. Spawning, but not courtship, is correlated with the tidal cycle. Spawns occur most often during the mid flood to high-tide phase of the eye le. Fish of both sexes are capable of multiple spawns per day. Both territorial and non territorial males acquire nuptial colouration between emergence from overwintering torpor and the start of the spawning season. Nonterritorial males are vigorously excluded from territories by the resident males and appear to contribute little to the reproductive effort of the population. Courtship and spawning occur only within male's territories. Group spawning was not observed. Sexual dichromatism and reproductive behaviour in the cunner are discussed with reference to other labrid species.

Dualistic reproductive behavior in the protogynous wrasseThalassoma bifasciatum and some observations on its day-night changeover

1.Thalassoma bifasciatum is a protogynous wrasse with (partial) sexual dimorphism and male dichromatism. Sex-inversion takes place without affecting the color pattern. 2. Males with female-like color dress indulge in group spawning; males with the bright color pattern perform pair spawning. 3. Among the brightly colored males exists a well-established hierarchy. Dominant males only have a particular spawning area in which they spawn daily at a certain time around noon. The spawning area is optically marked by conspicuous behavior of the bright male. Courtship activities towards individual partners are rather superficial. 4. The female has the leading role in pair spawning. In the extremely short spawning act a female may release, simultaneously, more than 2000 eggs. 5. Group spawning occurs in well-populated reef areas only. The basic pattern of group spawning has many similarities to pair spawning. 6. Day-night changeover ofT. bifasciatum is closely correlated to the time of sunset and sunrise. 7. The possible biological significance of the dualistic spawning behavior is discussed, and advantages as well as drawbacks of studies in the sea and in aquaria are considered.

Spawning and Parental Behavior in Female Pairs of the Jewel Fish, Hemichromis Bimaculatus Gill

AbstractSeven homosexual female pairs were observed on 17 occasions in a total of 22 spawnings. On six occasions the paired females spawned together. Four of the pairs synchronized so well in laying that they deposited rows of eggs alternately or simultaneously on the same site. In fifteen of the spawnings, the behavior of the "partner" of the first spawning female could be summarized as follows: seven ate the eggs and did not spawn until 3.5 days later; three ate eggs but spawned the same day ; three skimmed (or fanned) but did not spawn until 5 or more days later; and two skimmed (or fanned) and then spawned 10 and 45 minutes later, respectively. Hence the partners regarded the eggs as food (majority) or as offspring (minority). None of the partners could be regarded as showing male behavior since their skimming did not resemble the fertilizing movements of the male, except when both laid eggs. Pair formation depended on willingness of the females to inhibit their attacks on each other and to co-operate while maintaining a territory. Responses that seemed to check aggressiveness in the pair mate included the "estrous stance" and quivering. Homosexual groups that did not inhibit aggressiveness developed hierarchies and partial territories instead of pairs. On 11 of the 17 occasions of spawning, both females fanned the eggs and exhibited other parental behavior similar to that of heterosexual pairs. Twice, succcessful exchanges were made for fertilized spawn of Acquidens portalegrensis. These two pairs raised the young competently for 18 and 21 days, respectively, or fully as long as the heterosexual pairs maintained their young under our experimental conditions. It is concluded that female pairs of H. bimaculatus spawn in accordance with the chance synchronization of their separate estrous cycles, although some acceleration or inhibition of the cycle of the partner may result from the activities of the first to spawn. Since bisexual behavior could not be demonstrated, it appears likely that cichlid species performing the Hemichromis type of courtship have only one neuromuscular mechanism that with slight modifications is used by both sexes.