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1.
Eckward W. Heymann 《Behavioral ecology and sociobiology》1998,43(1):37-45
This study examines the hypothesis that sexual selection has shaped patterns of olfactory communication in wild moustached tamarins, Saguinus mystax. Do sex differences exist in frequencies and in the intensity of scent marking, in the use of different scent-marking types, and in behavioural responses to scent marks? Scent marking (anogenital, suprapubic, sternal) and behavioural responses (sniffing and overmarking) were recorded in four groups (ten adult and subadult males, seven adult and subadult females in all groups combined) in north-eastern Peru. Frequencies and intensity of scent marking were significantly higher in female tamarins. Males and females did not differ in the use of anogenital marking, but suprapubic marking was employed significantly more often by females. Only 10% of scent marks were monitored by another group member, and only 5% were overmarked by another group member. Most sniffing of scent marks was done by males, and males sniffed at marks produced by females significantly more often than at marks produced by males. Both sexes overmarked scent marks with similar frequency, but females overmarked scent marks produced by males significantly more often than those produced by females. An increase in frequencies of scent marking was observed in two females of one group after the death of the reproducing female, but frequencies of scent marking remained the same in the males of this group. The female-biased rates of scent marking are consistent with predictions made by sexual selection theory for species with substantial male care for offspring and strong reproductive competition between females. However, a decisive test of the proposed role of sexual selection will only be possible with more field data on patterns of olfactory communication in other callitrichine species. 相似文献
2.
In monogamous species, females often choose between males according to the quality of the territories they defend, but the
extent to which females themselves contribute to territory defence is frequently underestimated. Here we test for differences
in male and female roles during paired scent-marking bouts, a key component of territorial defence, in a monogamous antelope.
In two populations (Kenya, Zimbabwe) of klipspringer, Oreotragus oreotragus, both males and females usually scent-marked at the same site, but there were significant differences between sexes in terms
of investment within bouts. Females initiated most bouts, thus dictating the marking strategy of the pair. Males initiated
relatively few bouts, but deposited more scent marks per bout than females and were usually the last to scent-mark before
leaving the site; they marked on the same branches as the female and thus overmarked her scent. Both sexes deposited more
marks during paired than solo visits. Immediately preceding and following scent-marking bouts, males approached females and
females left males more often than expected. Female scent-marking rates were higher when they were receptive than at other
times, and this increase was matched by elevated marking rates of males. Females may increase marking rates when they are
receptive in order to test the quality of their mate or to incite male competition. However, these ideas are unlikely to explain
female scent-marking behaviour outside the mating season, which appears to be related primarily to territorial defence. We
suggest that these differences in investment in scent-marking bouts are consistent with predictions that females may be autonomously
territorial and that overmarking of female scent by males is a form of mate-guarding.
Received: 17 November 1999 / Received in revised form: 24 February 2000 / Accepted: 13 March 2000 相似文献
3.
Scent-marking is a frequent behaviour of highly social ground squirrels and might play an important role in their social dynamics.
Female Columbian ground squirrels exhibit considerable scent-marking during the reproductive period. We examined how gestating
and lactating females responded to jugal gland scent-marks of same-sexed and opposite-sexed conspecifics with attention to
genetic relatedness and the geographical location of the territory of individuals. We tested the dear-enemy, threat-level
and kin-discrimination hypotheses to explain patterns of scent-marking. Females sniffed the scent of non-neighbouring males
significantly longer than other types of scent categories and tended to over mark the scent of females more than the scent
of males. Furthermore, females sniffed significantly longer at scents during gestation than during lactation. We concluded
that scent-marking mainly functioned in the defence of female territories and for protection of pups against infanticidal
females (threat-level hypothesis). Our results were also in accordance with the kin-discrimination hypothesis, because greater
attention was paid to the marks of non-kin females. Kin females might not pose an infanticidal threat, perhaps explaining
greater tolerance among related reproductive females. We concluded that scent-marking may be a relatively low-cost means of
territorial defence, as well as a means of communication of aspects of individual identity. 相似文献
4.
Peter M. Kappeler 《Behavioral ecology and sociobiology》1998,42(6):411-421
The goals of this study were to investigate the transmission and possible functions of chemical signals in intragroup communication
among ring-tailed lemurs, Lemur catta. In particular, I examined the effects of sex on these processes because sexual selection theory predicts specific functions
for chemical signals. I recorded all interactions with 214 scent marks of 11 male and 9 female ring-tailed lemurs during the
first 10 min following their deposition. I found that 62% of these scent marks were investigated with a median latency of
30 s and that 89% of investigated scents were also counter-marked by the receiver. The type of focal scent mark (male or female
anogenital and male antebrachial mark) had a significant effect on both the timing and type of response. Males investigated
and counter-marked female scents more often than vice versa, but significant second-order transitions suggested that the behavior
of an animal was not only influenced by the immediately preceding scent mark and that a scent is not completely masked by
a counter-mark. There was no evidence for an audience effect, and only social rank of female senders had an effect on receivers.
Variation in the response of receivers across reproductive seasons as a function of senders' sex indicated that female scents
may function in mate attraction and competition among females, whereas male scents may be primarily used in intrasexual competition.
Three main conclusions emerged. First, the exchange of olfactory signals within groups was highly structured and surprisingly
efficient. Second, olfactory signals may constitute general mesasages whose transfer is partly controlled by the receiver.
Finally, sexual selection theory provides a useful theoretical framework for functional examinations of mammalian olfactory
communication.
Received: 13 June 1997 / Accepted after revision: 20 March 1998 相似文献
5.
We provide evidence that male lizards can use chemosensory cues to identify individual females and probably therefore maintain
long-term associations with these females in the wild. In the laboratory, males preferentially followed the scent trail of
their vitellogenic female “partner” rather than that of another vitellogenic female. Our 5-year field study of the small viviparous
scincid lizard (Niveoscincus microlepidotus) in alpine Tasmania showed that sexually mature males and females commonly formed “pairs” for long periods (on average 29 days).
These pairs occurred primarily during the mating season, always involved one adult male and one adult female, and usually
involved vitellogenic rather than gravid females. Our laboratory experiments suggest that a significant factor in maintaining
those prolonged partnerships is male scent trailing of partners.
Received: 28 October 1997 / Accepted after revision: 28 May 1998 相似文献
6.
Effects of male dominance and courtship display on female choice in the ring-necked pheasant 总被引:7,自引:0,他引:7
Male traits and behaviours acting in mate choice and intrasexual competition are expected to be congruent. When studying
their evolution, this often makes it difficult to differentiate between these two components of sexual selection. Studies
are therefore needed on mate choice in conjunction with the role of displays and dominance. We present the results from two
experiments conducted to investigate the effects of male dominance and courtship displays on female choice in the ring-necked
pheasant, Phasianus colchicus, controlling for differences in morphological male traits. We found: (1) different courtship behaviours had different effects
on female choice: females were mainly attracted by the feeding courtship behaviour, while another courtship display (the lateral
display) was effective in producing the copulation-acceptance response by the females; (2) subordinate males performed the
courtship behaviour before females less frequently than dominant males, and females reinforced intrasexual selection by choosing
dominant males, and (3) subordinate males in visual contact with a dominant became less attractive to females. The results
support the idea (armament-ornament model) that female pheasants may benefit from using traits selected in male-male competition
as clues for mate choice.
Received: 23 October 1997 / Accepted after revision: 7 October 1998 相似文献
7.
Rocky Mountain bighorn rams use three distinct tactics in competition for mates. Two tactics (tending and blocking) feature
defense and cooperative mating over a relatively prolonged consort period (up to 3 days). In the coursing tactic, subordinate
rams fight dominants for temporary copulatory access (lasting seconds) to defended ewes. By combining population-wide genetic
(microsatellite) exclusion of paternity, behavioral data and a model of bighorn reproductive competition, we estimated that
coursing rams fathered 44% of 142 lambs assigned paternity in two natural populations. In one population, the probability
of successful defense against coursing was lowest among rams that had many female consorts and held highest dominance rank.
Even so, per capita annual male reproductive success was positively associated with social rank in both herds when measured
in terms of fall conceptions. The proportion of coursing versus defending ram matings in each population (0.36 and 0.39) was
similar to the corresponding fraction of lambs (0.43 and 0.47) fathered by coursing rams, suggesting that sperm competition
approximated a fair lottery. Male traits important in gaining social status and obtaining cooperative consorts with ewes were
different and potentially in conflict with those needed to defend against (and practise) coursing. Although the concussive
weapons (horns) of rams are less dangerous than, for example, the piercing weapons of other bovids, injury from falls and
horn blows during coursing brawls may cause death, handicap future mating competition or increase the risk of predation. Coursing
is a rare example of an unconventional alternative mating tactic that is high-gain and high-risk.
Received: 17 April 1996 / Accepted after revision: 15 March 1997 相似文献
8.
Time budgets and foraging in a Malagasy primate: do sex differences reflect reproductive condition and female dominance? 总被引:5,自引:0,他引:5
Claire A. Hemingway 《Behavioral ecology and sociobiology》1999,45(3-4):311-322
Female mammals commonly employ behavioral tactics of modulating activity levels and foraging behavior to counter the energetic
burden of reproduction; these behavioral changes are reflected as intersexual differences. Traditional views of Malagasy primates
posit that high reproductive costs select for female dominance which guarantees to energetically stressed females priority
of resource access. I tested predictions regarding reproductive influences on sex differences in time budgets and foraging
behavior using two groups of Milne-Edwards' sifaka (Propithecus diadema edwardsi) in southeastern Madagascar. Compared to males, females increased neither feeding nor resting time during gestation or lactation.
Sex differences were essentially absent in all foraging time variables examined (time, duration, rate). In contrast, dietary
composition diverged between the sexes in some months. The possibility that females selected particular food items to boost
nutrient and energetic intake to meet increased requirements during reproduction must be further clarified with nutritional
analyses. Sex differences in plant part choices coincided with lactation in one of the two study groups. Thus, the timing
of sex differences in feeding patterns of P. d. edwardsi only partially supports the prediction that sex differences are most pronounced during the period of greatest female energetic
demand. A comparative review indicated no tight association between female dominance and sex differences in foraging among
Malagasy primates. Traditional female dominance theory falls short of explaining the observed patterns. The results of my
study coupled with recent evidence suggest that non-behavioral tactics involving energy conservation and storage require further
attention as mechanisms by which female lemurs cope with reproductive costs.
Received: 12 June 1998 / Accepted after revision: 10 October 1998 相似文献
9.
The reproductive biology of the alfonsino Beryx splendens was studied by histological examinations, gonadosomatic index and macroscopic scales of maturation of a large sample of gonads.
Alfonsino is a gonochoric species. The size-frequency distribution of the sex ratio was bimodal and considered to be due to
size dimorphism. In New Caledonia, the breeding period of this species occurs during the southern summer, with a peak in December
to January. The spawning stage is attained at a minimum fork length of 28 cm for females and 33 cm for males. The size at
which 50% of the population attain sexual maturity (FL50) is 33.2 cm for females and 34.5 cm for males. Maximum potential fecundity is estimated to lie between 270 000 to 675 000
eggs for fish between 34 and 40 cm in fork length. It was possible to differentiate vegetative zones, in which juvenile alfonsino
grow until they reach maturity, from reproductive zones (fishing grounds) which are inhabited by mature individuals. The larvae
and juveniles could be carried from the reproductive zone to the vegetative zone by currents in an oceanic eddy system.
Received: 26 April 1996 / Accepted: 20 September 1996 相似文献
10.
Leslie Digby 《Behavioral ecology and sociobiology》1995,37(1):51-61
Reproduction in marmoset and tamarin groups is typically restricted to a single dominant female, but it is unclear why subordinate females tolerate delayed reproduction. The presence of two breeding females in free-ranging groups of common marmosets (Callithrix jacchus) presented a unique opportunity to examine differences in the reproductive strategies of dominant and subordinate females. Three groups were monitored for 12–18 months at a forest reserve in northeastern Brazil. Data on infant care were collected during two consecutive all-day follows every 10 days until the infants were 2 months old. Carrying patterns for infants born to dominant females were similar to those observed in groups containing a single breeding female. All group members over 5 months of age participated in infant care, and dominant females allowed some group members to carry their infants from the 1 st day of life. In contrast, subordinate females were protective of their offspring and were their sole caretakers for at least a week following birth. One infant born to a subordinate was killed in an attack involving the dominant female. Overall, dominant females gave birth to more infants and had higher infant survival than did subordinate breeding females. subordinate females were successful in rearing young only when the timing of births was such that they did not overlap with the dependency period of infants born to the dominant female. These patterns suggest that subordinate females may face resource competition, especially over access to helpers. In times of severe competition, subordinate females that delay reproduction may be avoiding a wasted reproductive effort. 相似文献
11.
Genetic monogamy in the common loon (Gavia immer) 总被引:4,自引:0,他引:4
Walter H. Piper David C. Evers Michael W. Meyer Keren B. Tischler Joseph D. Kaplan Robert C. Fleischer 《Behavioral ecology and sociobiology》1997,41(1):25-31
We conducted behavioral observations and genetic analysis on breeding pairs of common loons in the upper Great Lakes region
from 1993 through 1995 to look for behavioral evidence of extrapair copulations (EPCs) and to determine parentage of young.
Pairs remained close to each other (usually within 20 m) during the pre-laying period, leaving little opportunity for EPCs
to occur. Males and females both maintained physical proximity by approaching each other when they became separated. Copulations
were obvious but infrequent, occurring about once every other day during the pre-laying period. Multilocus DNA fingerprinting
was consistent with behavioral findings: 58 young from 47 different families were all genetic offspring of parents that raised
them. Perfect genetic monogamy (genetic parentage of young by parents that rear them) in loons might arise as a consequence
of the need for vigorous territorial defense to prevent territorial takeover.
Received: 8 August 1996 / Accepted after revision: 22 March 1997 相似文献
12.
In many species of birds and mammals with a co-operative breeding and rearing system, offspring survival is positively related
to the number of helpers. In the New World callitrichine primates (marmosets and tamarins), adult males are considered as
particularly valuable helpers, and female reproductive success may depend strongly on the males' contribution to infant care.
We analysed the number of offspring (infants, juveniles) in groups of wild pygmy marmosets, Cebuella pygmaea (Callitrichinae, Cebidae, Primates), in relation to the number of adult males and to the number of adult and subadult group
members. In contrast to other callitrichines with a co-operative system of infant care, no relationship was found between
the number of adult males and the number of infants and offspring. However, there was a significant positive relationship
between the number of juveniles and the number of adult and subadult group members. The lack of a relationship between infant
and adult-male number is interpreted as resulting from the reduced importance of adult males as helpers in pygmy marmosets
in comparison to other callitrichines, probably due to the reduced costs of infant care. The relationship between the number
of juveniles and the number of adult and subadult group members is in accordance with increased offspring survival in larger
groups, as observed in other primates.
Received: 1 February 1999 / Received in revised form: 5 June 1999 / Accepted: 29 June 1999 相似文献
13.
Dominance status influences the fitness of many mammals. Using African striped mice Rhabdomys pumilio, we tested whether (1) dominant females have greater reproductive success than subordinate females, (2) dominant females
influence the reproductive output of subordinate females when they are housed in close proximity, (3) reproductive output
of a female changes in response to the dominance status of her neighbours, and (4) whether prolonged association between individuals
influences the variance in reproductive success between dominants and subordinates (i.e. the ‘dear enemy’ phenomenon). The
size and mass of litters of dominants increased significantly when housed adjacent to subordinates than when housed apart.
The litter size and mass of subordinates remained unchanged, although subordinates spent significantly more time with their
pups when housed close to dominants than when housed apart; time spent with pups by dominants remained unchanged. Moreover,
females modified their reproductive output and behaviour in relation to the dominance status of their neighbours. Following
prolonged association, dominants still had greater reproductive success, but now, the time spent with pups decreased in subordinates.
We suggest that dominants adopt a strategy to increase the reproductive value of their litter, whereas subordinates adopt
a pup defence strategy. These strategies are flexible and are influenced by the dominance status and period of association
between neighbours, so that females could maximize their fitness in response to varying social conditions. 相似文献
14.
Summary There is no consensus about the function of scent-rubbing, a widespread behaviour in which mammals rub their bodies vigorously in substances, many strong-smelling and some artificial, such as rotting meat, intestinal contents and engine oil. Here we suggest that scent-rubbing is involved in status advertisement and that, as in assessment using scent marks, the mechanism used by competitors to assess potential opponents may be scent-matching. In scent-matching a resource holder is assessed (identified) by comparing its odour with odours on or near the defended resource. In scent marking the odour originates from the resource holder (glandular secretion, urine and faeces); in scent-rubbing the odour originates in the environment.A prerequisite of unambiguous scent-matching is that the odour of scent-marks should be uniquely characteristic of one individual. This may be why marking substances are very complex chemically. Scent-rubbing often occurs with scent-marking and, rather than acting independently of scent-marking, the odours acquired may either (i) add to the complexity of the signal, thus reducing signal ambiguity, or (ii) increase the range of the signal by adding a strong smelling component.Subordinates could potentially cheat by rubbing in the same odours as the resource holder. Resource holders could prevent cheating (i) by checking other status cues and by testing competitors whose scent matches, then escalating contests when the competitor's fighting ability (more formally, Resource Holding Power) proves to be lower than that of a resource holder and (ii) by mixing the substances used for scent-rubbing with the unique substances used in scent-marking. 相似文献
15.
Parental investment, potential reproductive rates, and mating system in the strawberry dart-poison frog, Dendrobates pumilio 总被引:1,自引:0,他引:1
We studied the effect of relative parental investment on potential reproductive rates (PRRs) to explain sex differences in
selectivity and competition in the dart-poison frog Dendrobates pumilio. We recorded the reproductive behavior of this species in a Costa Rican lowland rainforest for almost 6 months. Females spent
more time on parental care than males, and `time out' estimates suggest that PRRs of males are much higher than than those
of females, rendering females the limiting sex in the mating process. Males defended territories that provide suitable calling
sites, space for courtship and oviposition, and prevent interference by competitors. Male mating success was highly variable,
from 0 to 12 matings, and was significantly correlated with calling activity and average perch height, but was independent
of body size and weight. Estimates of opportunity for sexual selection and variation in male mating success are given. The
mating system is polygamous: males and females mated several times with different mates. Females were more selective than
males and may sample males between matings. The discrepancy in PRRs between the sexes due to differences in parental investment
and the prolonged breeding season is sufficient to explain the observed mating pattern i.e., selective females, high variance
in male mating success, and the considerable opportunity for sexual selection.
Received: 9 June 1998 / Received in revised form: 27 March 1999 / Accepted: 3 April 1999 相似文献
16.
Sperm economy and limitation in spiny lobsters 总被引:5,自引:0,他引:5
Sperm limitation, when female fertilisation success is constrained by the supply of sperm, is generally perceived to be an
uncommon feature of reproduction in species which directly transfer gametes during copulation. Male size, previous copulations,
and the balance of expected reproductive return and future mating opportunity may, however, limit the amount of sperm males
transfer to females. We used laboratory experiments where mate size could be manipulated and its consequences on spermatophore
size and clutch size determined, to show that in two genera of spiny lobsters (Crustacea: Palinuridae) male reproductive output
limits the size of clutches brooded by females. In Panulirus argus from the Florida Keys, we show that while male size affects spermatophore area, males also vary the amount of ejaculate positively
with female size. Furthermore, the area of the spermatophore has a greater influence than female size on subsequent clutch
weight. In Jasus edwardsii from New Zealand, female size, male size and mate order all affect clutch weight. In both species, clutches fertilised by
small males in the laboratory are significantly smaller than clutches fertilised by large males. These results suggest that
to ensure they receive sufficient sperm, females should either mate several times prior to oviposition, mate as early as possible
in the reproductive season, or choose large, preferably unmated males as partners and thus compete with other females for
preferred males. Sperm-limited female fecundity has the potential to limit the egg production of fished populations where
large males are typically rare.
Received: 18 May 1998 / Received in revised form: 20 November 1998 / Accepted: 30 November 1998 相似文献
17.
Reproductive dominance and differential ovicide in the communally breeding burying beetle Nicrophorus tomentosus 总被引:4,自引:0,他引:4
Michelle Pellissier Scott 《Behavioral ecology and sociobiology》1997,40(5):313-320
Communal breeding can be characterized by the division of reproduction among cooperating individuals and, if the distribution
of reproduction is inequitable, by the mechanisms for achieving skewed reproductive success. The burying beetle (Nicrophorus tomentosus) is a facultative communal breeder. Unrelated adults, especially females, provide extensive parental care to broods of mixed
parentage. The frequency and degree of reproductive skew between two females were examined experimentally. On medium-size
carcasses, the proportion of eggs attributed to each female was not significantly different from random in 42% of the broods,
skewed in 42% and not shared in 16%. Although reproduction was usually skewed in favor of the larger female, the relative
sizes of the two females did not predict the degree of skew. On large carcasses, the proportion of eggs attributed to each
female was not different from random in 87% of the broods and weakly skewed in 13%. Several mechanisms for biasing reproductive
success were investigated. Females increase the proportion of their offspring in the brood by committing differential ovicide.
Secondly, burying and preparing a carcass cooperatively stimulates ovarian development of the larger female and slows it for
the smaller female, reducing or delaying oviposition by the subordinate. Thirdly, larger females are more likely to be dominant
and are more fecund than smaller females.
Received: 20 July 1996 / Accepted after revision: 30 November 1996 相似文献
18.
Flat lizards (Platysaurus broadleyi) at Augrabies Falls National Park, South Africa, are restricted to rocky terrain where the predominant tree is the Namaqua
fig (Ficus cordata cordata). P. broadleyi readily feeds on Namaqua figs when they are available, and the lizards sometimes form large (maximum recorded=134) congregations
under fruiting fig trees. The distance lizards travel to fruiting trees also exceed normal daily foraging distances. Location
of fruiting fig trees by a lizard can have a high pay-off because figs are energetically rich and trees fruit irregularly
and asynchronously, resulting in a resource that is available, but unpredictable in time and space. The prediction that bird
activity in fig trees provides a cue to the presence of ripe figs was tested experimentally. By placing cages containing birds
and empty control cages in trees devoid of fruit, we demonstrated that P. broadleyi are drawn to fig trees with high bird congregations. We also tested if the presence of a fig tree was necessary to draw lizards
to bird congregations by placing cages containing birds and empty control cages in a matched-pairs design on rock away from
trees. Namaqua fig trees were not necessary to draw lizards to bird congregations.
Received: 12 May 1998 / Accepted after revision: 30 November 1998 相似文献
19.
Socially dominant males often signal their status to rival males and/or females. We tested the hypotheses that Lacerta monticola femoral gland secretions and copulatory plugs convey chemical information about male identity and dominance status. We estimated male dominance status by staging male–male agonistic encounters in a neutral arena. We then conducted two experiments to compare male tongue-flick behavior toward chemical stimuli consisting of cotton swabs bearing (1) deionized water (control), the lizard’s own femoral secretions, and the femoral secretions of another male and (2) phosphate-buffered saline solution (control), the lizard’s own plug products, and the plug products of another male. Results indicate that males discriminated their own femoral secretions and plugs from those of other males. They also discriminated morphological attributes of other males that were associated with dominance status based on chemical cues arising from femoral secretions and discriminated the dominance status of other males based on chemical cues arising from the plugs. Femoral secretions that convey information about male identity and dominance status may be hypothesized to function in the establishment of L. monticola dominance hierarchies through scent-marking of territories. We suggest that copulatory plugs and femoral secretions may allow males to scent-mark the female body and postulate that this behavior may influence male and female reproductive decisions under selective pressures of sperm competition. 相似文献
20.
Effects of food type and ration on reproductive maturation and growth of the sea urchin Strongylocentrotus droebachiensis 总被引:1,自引:0,他引:1
We investigated the effects of food quality and quantity on reproductive maturation and growth of juveniles of Strongylocentrotus droebachiensis (Müller) in a 22 month laboratory experiment in which we fed sea urchins four diets: (1) kelp (Laminaria spp.) for 6 d wk−1 and mussel (Mytilus spp.) flesh for 1 d wk−1 (KM); (2) kelp for 7 d wk−1 (high ration, KH); (3) kelp for 1 d wk−1 (low ration, KL) and (4) no food other than encrusting coralline algae (NF). At their first and second opportunity for reproduction,
all sea urchins in the KM and KH treatments, and most in the KL treatment were reproductively mature, whereas all sea urchins
in the NF treatment remained immature. Gonad index differed significantly among all fed treatments at first and second reproduction,
and was highest in the KM and lowest in the KL treatment. Gonad index was similar in both sexes at first reproduction, but
it was higher in females than in males at second reproduction. Diet had little or no effect on the relative abundance of spermatocytes,
spermatozoa, or nutritive phagocytes in testes at first and second reproduction. In ovaries, nutritive phagocytes were significantly
more abundant in females in the KM and KH treatments than in the KL treatment at first reproduction, and significantly more
abundant in unfed (NF) than fed (KM, KH, KL) females at second reproduction. Mean oocyte size was similar in all fed females
at first reproduction, but significantly larger in fed than unfed females at second reproduction. Mean ovum size was similar
in all fed females in both reproductive periods. Increase in test diameter was greatest in the KM treatment and smallest in
the KL treatment; sea urchins in the NF treatment decreased slightly in size. Survival was 95 to 100% in all fed sea urchins
but significantly lower in unfed ones. The feeding rate on kelp was significantly greater in the KL than the KM and KH treatments.
In the KM treatment, the feeding rate on kelp increased significantly over a 6 d period after mussel flesh was provided. Our
results demonstrate that a diet of high food quality and quantity accelerates reproductive maturation and growth rate, and
enhances gonad production and survival in juvenile and young adult S. droebachiensis. These findings contribute to our understanding of the reproductive ecology of S. droebachiensis in habitats with differing food supplies (e.g., kelp beds and barrens). Our results also can be used to improve aquacultural
practices for sea urchins.
Received: 3 June 1998 / Accepted: 2 February 1999 相似文献