The reproductive cycle of the roundel skate Raja texana

The reproductive cycle of Raja texana was determined from 63 females (510-630 mm total length, L(T)) and 81 males (355-546 mm L(T)) collected from the Gulf of Mexico. The results, based on follicle size, mature spermatocysts and gonadosomatic index (I(G)) suggests year-round reproductive activity.     

Biology of the silky shark Carcharhinus falciformis (Carcharhinidae) in the eastern Indian Ocean, including an approach to estimating age when timing of parturition is not well defined

Biological data were recorded for 1265 silky sharks Carcharhinus falciformis collected from fish landing sites in eastern Indonesia. These represented catches taken in most calendar months by gillnetting and longlining in the eastern Indian Ocean and contained individuals ranging from embryos to fully mature adults. The growth zones in centra, which were shown to form annually, were counted in the vertebrae in a sub-sample of 200 fish for ageing purposes. The embryo lengths in the 5 months for which there were such data, and the presence of neonates in virtually all months, however, indicated that birth occurs throughout the year and thus there was no well-defined birth date for ageing individual fish. The approximate birth date of each individual was thus estimated from a combination of the total length (L(T) ) at capture and backcalculated L(T) at the formation of the birth zone and at the first and last growth zones in the vertebral centra, together with the period that had elapsed between the formation of those last two growth zones. The number of eggs or embryos in uteri ranged from two to 14, with a mean of 7·2. The estimated mean L(T) at birth of females (811 mm, range: 799-823 mm) and males (812 mm, range: 794-830 mm), derived from the backcalculations corresponding to the birth zones in the centra, were not significantly different (P > 0·05). The L(T) ranges in the catches of post-natal females (570-2592 mm) and males (553-2289 mm) taken by gillnetting were wider than those of the females (1177-2623 mm) and males (1184-2409 mm) taken by longlining. The oldest female and male were 19 and 20 years-old, respectively. The von Bertalanffy growth curves for the two sexes did not differ significantly. The growth coefficient, k, and the asymptotic length, L(T∞). were 0·066 year?1 and 2994 mm for the curve fitted to the combined data for females and males. The lengths L(T50) and ages A(50) at which C. falciformis attained maturity were 2156 mm and 15 years for females and 2076 mm and 13 years for males. The very high proportion of C. falciformis with lengths 相似文献   

Reproductive biology of the spotback skate Atlantoraja castelnaui in the south-west Atlantic Ocean

This study provides information on the reproduction of spotback skate Atlantoraja castelnaui. A total of 232 individuals (119 females and 113 males) were obtained from surveys carried out between 2003 and 2006, from the south-west Atlantic Ocean, between 34 and 42° S and <50 m deep; another 514 specimens (241 females and 273 males) were obtained between 2005 and 2007 from commercial fishery operations carried out in the same area and landings in the port of Mar del Plata, Argentina. Males ranged from 185 to 1250 mm total length (L(T) ) and females from 243 to 1368 mm L(T) . Length at maturity was estimated to be 980 mm for males and 1089 mm L(T) for females. Lack of variation of testis mass together with the continuous production of mature spermatocyst and spermatozoa in deferent ducts suggested that males can reproduce throughout the year. Females reproduced year-round with peaks of reproductive activity an integral part of a continuous cycle. This conclusion is corroborated by the seasonal variation of ovaries, oviducal gland and the occurrence of females with eggs in the uterus throughout the year. Results from this study indicate that A. castelnaui is very susceptible to fishery pressure.     

Trophic ecology of Atlantic bluefin tuna Thunnus thynnus larvae

Feeding intensity, diet composition, selectivity, energy ingestion and dietary niche breadth of larval Atlantic bluefin tuna Thunnus thynnus were studied on the eastern (Mediterranean) spawning grounds of the species. Larval T. thynnus were collected in the Balearic Archipelago (north-west Mediterranean Sea) during 2004 and 2005 using surveys specific for larval scombrids. Larvae between 2·6 and 8·7 mm standard length (L(S) ) are diurnal feeders, and 94% of the guts collected during daylight hours were full. The mean ±s.d. number of prey per gut was 7·1 ± 5·7, with mean ±s.d. ranging from 3·0 ± 1·6 in the smallest T. thynnus larvae to 11·1 ± 5·8 in 5·0-6·0 mm L(S) larvae. Up to 21 prey were found in a single larval gut (5·0-6·0 mm L(S) ) at the end of the day. Larvae progressively selected larger prey and exhibited increased carbon content concurrent with preflexion development of feeding and locomotory structures. Larvae of 5·0-6·0 mm L(S) exhibited positive selection of cladocerans over other prey (Chesson's index), whereas copepod nauplii dominated the diets of earlier stages. The dietary niche breadth measured increased initially but decreased at c. 5·5 mm L(S) . Appendicularians were found in the diet of larger larval sizes, but no piscivory was observed. Results are discussed in light of the sparse existing data for larval T. thynnus and other larval tuna species.     

Reproductive biology of the lesser guitarfish Zapteryx brevirostris from the south-western Atlantic Ocean

This study provides the first detailed information on the reproductive biology of the lesser guitarfish Zapteryx brevirostris in the south-western Atlantic Ocean between latitudes 34° and 42° S. A total of 320 males (196-647 mm total length, L(T)) and 336 females (200-640 mm L(T)) were analysed. No significant differences were observed in size at 50% maturity between males (499 mm L(T)) and females (506 mm L(T)). Three seasonal patterns were related to the testes mass, the development of spermatocysts and the presence of spermatozoa in genital ducts. Females showed a 3 year reproductive cycle, with 2 years of ovarian maturation and 1 year of gestation, including a mean annual fecundity of one to two embryos. Synchronicity of both ovulating females and males with sperm in genital ducts indicated that ovulation and hence mating occurs during winter. Birth was assumed to occur during winter, but neither ovulation nor mating is simultaneous with this reproductive event. Despite its low economic value, a decline in abundance in the region, together with a low reproductive efficiency, indicates that the Z. brevirostris population should be monitored closely.     

Biennial reproductive cycle in an extensive matrotrophic viviparous batoid: the sandyback stingaree Urolophus bucculentus from south-eastern Australia

Urolophus bucculentus, the largest urolophid species found in southern Australia, exhibits a biennial reproductive cycle. Ovulation occurs during October to January followed by a 15-19 month period of gestation followed by parturition during April to May and a short rest period while the ovarian follicles continue to develop for subsequent ovulation. Male breeding condition peaks during April to June to coincide with the period of parturition. Urolophus bucculentus has the highest matrotrophic contribution reported for any urolophid species, with a mean wet mass gain from egg in utero (4 g) to full-term embryo in utero (250 g) of c. 6250% (maximum c. 7200%), and perhaps explains the biennial female reproductive cycle where 50% of females contribute to each year's recruitment. Litter size (one to five) increases with total length (L(T) ). Females reach a longer maximum L(T) (L(Tmax) ) than do males (885 v. 660 mm). The L(T) at maturity for males and females at 50% mature (L(T50) ) is c. 414 mm (63% of L(Tmax) ) for males and c. 502 mm (57% of L(Tmax) ) for females, length at maternity indicates that recruitment production occurs later in life at c. 632 mm L(T) (71% of L(Tmax) ).     

Early life characteristics of pike, Esox lucius, in rearing ponds: temporal survival pattern and ontogenetic diet shifts

Survival, biomass and diet of pike, Esox lucius , larvae and juveniles were studied over 3 years by stocking free embryos at a density of six fish m⁻² in 12 drainable outdoor ponds. The ponds were sequentially drained at six larval/juvenile developmental stages, up to a total length (T.L.) of 139 mm. The mean rate of survival at harvest decreased irregularly over time and the highest mortality rates were recorded during the early larval period (13 to 27 mm t.l .) and two intervals of the juvenile period (46 to 99 mm T.L. and 121 to 139 mm t.l .). Mean biomass increased dramatically between 46 mm T.L. (19.8 kg ha⁻¹) and 121 mm T.L. (181.8 kg ha⁻¹) and stabilized between 121 and 139 mm t.l . Sharp increases in the mean weight coefficient of variation were recorded during the early larval period (13 to 27 mm t.l .) and between 74 and 121 mm t.l . (development of cannibalism). Diet breadths were relatively narrow in pike larvae and reached maximum levels in 99 mm t.l . juveniles. Average-sized pike exhibited a sequence of size-dependent shifts from a diet composed primarily (in terms of weight) of micro-crustaceans (at 13 mm t.l .), to chironomid larvae (at 74 to 99 mm t.l .), and finally macrocrustaceans (at 121 to 139 mm t.l .). Cannibalism was detected first among the largest fish at the 74 mm t.l . stage. Between-year diet similarity at various developmental stages was consistently high. In 70 mm t.l . fish harvested from different ponds, we found significant among-pond differences in diet composition; however, similar trends of diet changes in relation to fish size were observed from pond to pond. Our results are discussed in light of existing knowledge of young pike trophic ecology and current aquaculture practices.     

Proposed standard mass equations for European chub Leuciscus cephalus in Italy

Total length (L(T)) and mass measurements of 28,596 specimens of European chub Leuciscus cephalus, collected from a variety of waterways across Italy, were used to compute standard mass (W(s)) equations by both empirical percentile (EmP) and regression line percentile (RLP) methods. The use of the EmP W(s) equation [log(10) W(s) = -4·79 + 2·68log(10) L(T) + 0·10(log(10) L(T))(2)] to compute relative mass (W(r)) of L. cephalus in Italy is suggested, as it was not influenced by length-related bias (L(T) range of application = 70-470 mm).     

Life-history patterns of the mosquito-fish, Gambusia affinis, in the estuary of the Guadalquivir river of south-west Spain

SUMMARY. 1. The age, growth and reproduction of the small, introduced fish Gambusia affinis (Baird & Girard, 1853) were studied in the estuary of the Guadalquivir river.
2. The life-span was very short, the stock contained only two age groups: with annulus (1+ group; 10–12 months old) and without annulus (0+ group).
3. In both sexes growth restarted in April when the annulus appeared, but whilst 1+ males stopped growth, 1+ females grew steadily to June. Growth of 0+ spawners was only evident in September, the last month of the reproductive period. A differential growth rate between sexes was also evident.
4. 1+ specimens reproduced during May and June and their offspring from July to September. In both age groups somatic condition progressively declined during the spawning period.
5. The loss of condition and the disappearance of 1 + and the larger 04-specimens after reproduction may indicate the cost of a prolonged high level of reproductive effort.
6. The total fecundity (taken as the number of embryos) of 1 + females was represented by the formula: Fec=5.08 T.L. (mm) -170.07 and that of 0+ specimens by: Fec=2.23 T.L. (mm) -42.92. The maximum average monthly fecundity was reached in June when the length of the mother was at its greatest.
7. Length at first maturity was smaller in 0+ group than in the 1 + group; the difference between the two groups was greater in males (≅5 mm, T.L.) than in females (≅3 mm, T.L.). Also the average total length of 14-spawners was greater than 0+ spawners. There were significant differences in the overall sex ratio of 956 males to 2057 females.
8. The differences found in growth and reproduction between the two age groups suggest that life-history tactics may vary not only between different stocks but also within the same stock among its different components.     

Long-range afferents in the rat spinal cord. 1. Numbers, distances and conduction velocities.

The caudal extent of the penetration of primary afferent axons from the T12 and L1 dorsal roots and sural nerve has been investigated in adult decerebrate spinal rats. Microelectrode stimulation at the root entry zone (REZ) and at further caudal points in the spinal cord was used to generate antidromic action potentials in single fibres recorded in dorsal roots or peripheral nerves. A total of 209 units were recorded in T12 and L1 dorsal roots and 27% of these could be antidromically activated 10 mm caudal to the REZ. Fifteen percent of the units could be stimulated at the L4-5 border, 15 mm caudal to the T12 segment whereas 4.5% of the axons could be stimulated 25 mm caudally in the S4 segment, 11 segments caudal to the entry segment. Similar recordings made from units in the sural nerve showed that of all the sural axons that penetrated to the L6 segment 50%, 18% and 2% of these reached the S1, S2 and S4 segments respectively. The conduction velocities of these units were clearly in the A-beta range when recorded in the nerve but decreased on entering the spinal cord and were reduced by 83% at their caudal end point. The results show that substantial numbers of primary afferents have long-ranging caudal branches in areas beyond the regions of known postsynaptic effects. The functions of these caudal projections are unclear but they may represent a potential substrate for the development of functional connections under conditions of disease or denervation.     

The life histories of endangered hammerhead sharks (Carcharhiniformes, Sphyrnidae) from the east coast of Australia

The life histories of two globally endangered hammerhead sharks, Sphyrna lewini and Sphyrna mokarran, were examined using samples collected from a range of commercial fisheries operating along the east coast of Australia. The catch of S. lewini was heavily biased towards males, and there were significant differences in von Bertalanffy growth parameters (L(∞) and k) and maturity [stretched total length (L(ST)) and age (A) at which 50% are mature, L(ST50) and A(50)] between those caught in the tropics (L(∞) = 2119 mm, k = 0·163, L(ST50) = 1471 mm, A(50) = 5·7 years) and those caught in temperate waters (L(∞) = 3199 mm, k = 0·093, L(ST50) = 2043 mm, A(50) = 8·9 years). The best-fit estimates for a three-parameter von Bertalanffy growth curve fit to both sexes were L(∞) = 3312 mm, L(0) = 584 mm and k = 0·076. Males attained a maximum age of 21 years and grew to at least 2898 mm L(ST). The longevity, maximum length and maturity of females could not be estimated as mature animals could not be sourced from any fishery. Length at birth inferred from neonates with open umbilical scars was 465-563 mm L(ST). There was no significant difference in length and age at maturity of male and female S. mokarran, which reached 50% maturity at 2279 mm L(ST) and 8·3 years. Sphyrna mokarran grew at a similar rate to S. lewini and the best-fit estimates for a two-parameter von Bertalanffy equation fit to length-at-age data for sexes combined with an assumed mean length-at-birth of 700 mm were L(∞) = 4027 mm and k = 0·079. Females attained a maximum age of 39·1 years and grew to at least 4391 mm L(ST). The oldest male S. mokarran was 31·7 years old and 3691 mm L(ST). Validation of annual growth-band deposition in S. mokarran was achieved through a mark, tag and recapture study.     

Skeletal development and abnormalities of the vertebral column and of the fins in hatchery-reared turbot Scophthalmus maximus

To describe the skeletal development and abnormalities in turbot Scophthalmus maximus, samples were collected every day from hatching to 60 days after hatching (DAH). A whole-mount cartilage and bone-staining technique was used. Vertebral ontogeny started with the formation of anterior haemal arches at 5·1 mm standard length (L(S) ) c. 11 DAH, and was completed by the full attainment of parapophyses at 16·9 mm L(S) c. 31 DAH. Vertebral centra started to develop at 6·3 mm L(S) c. 16 DAH and ossification in all centra was visible at 11·0 mm L(S) c. 25 DAH. The caudal fin appeared at 5·1 mm L(S) c. 11 DAH and ossification was visible at 20·6 mm L(S) c. 37 DAH. The onset of dorsal and anal fin elements appeared at 5·8 mm L(S) c. 15 DAH and 6·3 mm L(S) c. 16 DAH, respectively. Ossifications of both dorsal fin and anal fin were visible at 20·6 mm L(S) c. 37 DAH. The pectorals were the only fins present before first feeding, their ossifications were completed at 23·5 mm L(S) c. 48 DAH. Pelvic fins began forming at 7·2 mm L(S) c. 19 DAH and calcification of the whole structure was visible at 19·8 mm L(S) c. 36 DAH. In the present study, 24 types of skeletal abnormalities were observed. About 51% of individuals presented skeletal abnormalities, and the highest occurrence was found in the haemal region of the vertebral column. As for each developmental stage, the most common abnormalities were in the dorsal fin during early metamorphic period (stage 2), vertebral fusion during climax metamorphosis (stage 3) and caudal fin abnormality during both late-metamorphic period (stage 4) and post-metamorphic period (stage 5). Such research will be useful for early detection of skeletal malformations during different growth periods of reared S. maximus.     

Effects of river flow on larval growth and survival of Japanese seaperch Lateolabrax japonicus (Pisces) in the Chikugo River estuary, upper Ariake Bay

The abundance and growth history of larval and juvenile Japanese seaperch Lateolabrax japonicus were investigated in the Chikugo River estuary, upper Ariake Bay, from 1990 to 2000. Growth during the larval period (up to 15 mm standard length, L _S, the size at recruitment into the estuary) was backcalculated using sagittal otolith microstructures by the biological intercept method. Growth rates in length declined at body sizes >14 mm L _S. High freshwater discharge through the Chikugo River was associated with high temperatures of the upper Ariake Bay where the larvae spend their planktonic life. Mean larval stage duration (days) from hatch to 15 mm ( D ₁₅) varied between 48·8 and 76·2 days and was inversely correlated with the estimated mean temperature history [mean daily temperature (° C) experienced by the larvae during the period from hatch to 15 mm, T ₁₅]. Mean abundance (number m⁻²) of larvae and juveniles was highest in years when T ₁₅, D ₁₅ and freshwater discharge were at intermediate levels. Although the abundance was not correlated with either of these variables, an exponential relationship between abundance and D ₁₅ was found when data collected during the highest river discharge years (1990, 1991 and 1998) were excluded. The increase in freshwater discharge through the Chikugo River probably had the potential to enhance or diminish Japanese seaperch recruitment in two ways: 1) it could increase recruitment probability by increasing temperature and larval growth and 2) high river flow also had the potential to decrease the probability of immigration into the river by increasing larval seaward dispersion, predation due to decreased turbidity and starvation due to decreased zooplankton prey abundance in the estuary.     

Early development of New Zealand hapuku Polyprion oxygeneios eggs and larvae

This study describes for the first time the normal development of New Zealand hapuku Polyprion oxygeneios embryos and larvae reared from fertilization to 11 days post-hatch (dph) at a constant temperature. Fertilized eggs were obtained from natural spawnings from communally reared captive wild broodstock. Eggs averaged 2 mm in diameter and had single or multiple oil globules. Embryos developed following the main fish embryological stages and required an average of 1859·50 degree hours post-fertilization (dhpf) to hatch. The newly hatched larvae (4·86 mm mean total length, L(T) ) were undifferentiated, with unpigmented eyes, a single and simple alimentary tube and a finfold that covered the entire body. Larvae relied on the energy from the yolk-sac reserves until 11 dph (7·33 mm mean L(T) ), when yolk-sac reabsorption was almost completed. Some of the major developmental stages from hatching to yolk-sac reabsorption were eye pigmentation (5 dph), upper jaw formation (7 dph), lower jaw formation (8 dph) and mouth opening (8-9 dph). By 9 dph, the digestive system consisted of pancreas, liver, primordial stomach, anterior and posterior gut; therefore, P. oxygeneios larvae would be capable of feeding on live prey. The developmental, morphological and histological data described constitutes essential baseline information on P. oxygeneios biology and normal development.     

The food of barramundi, Lates calcarifer (Bloch), in coastal and inland waters of Van Diemen Gulf and the Gulf of Carpentaria, Australia

Examination of the diet of Lates calcarifer , based on 3684 specimens of 4–1200 mm total length (T.L.), from two localities in north Australia showed it is an opportunistic predator with an ontogenetic progression in its diet from microcrustacea to macrocrustacea to fish. The increasing importance of fish in the diet of L. calcarifer in salt water (up to 87% of food consumed) involved a dietary shift from feeding on bottom-dwelling forms to pelagic forms. There were few differences in the diet of L. calcarifer between the two localities. Cannibalism was rarely encountered in the Gulf of Carpentaria although it was significant (11–4% of the diet of L. calcarifer of 1001–1200 mm T.L.) in Van Diemen Gulf. A significant correlation between predator and prey length was found for Ariidae, Dorosomidae, Engraulidae, L. calcarifer , Mugilidae and Polynemidae. The maximum prey/predator length ratio observed was 0–61 for the dorosomid, Nematolosa erebi.     

Distribution,abundance, and food habits of the snailfishLiparis tanakai in the Suo Sea,Seto Inland Sea

In order to examine the distribution, abundance, and food habits of the snailfish,Liparis tanakai, in the Suo Sea, western Seto Inland Sea of Japan, experimental fishing surveys were made using trawl nets on the night (1930–0340 h) of 26 May and 2 and 3 June, 1986. The study area was subdivided into 18 areas, each sampled by one trawl tow of 35 min duration. A total of 190 fish was collected during the surveys, and most fish (78.9%) were obtained from muddy substrata ranging in depth from 30 to 40 m at the middle area of the Suo Sea. The total length of the fish in the samples ranged from 72 to 273 mm. The overall length-frequency distribution formed a unimodal curve, the mode occurring at the class of 100–130 mm in total length. Of 151 fish examined, 146 (96.7%) had stomachs full of food, including a variety of small crustaceans and fish. Shrimps, especiallyCrangon affinis, ranked highest in importance in the diet ofL. tanakai. These biological data are compared with those of conspecifics from Sendai Bay, northern Honshu of Japan.     

Quantification of the maternal-embryonal nutritional relationship of elasmobranchs: case study of wobbegong sharks (genus Orectolobus)

The present study used wobbegong sharks (genus Orectolobus) to assess the threshold value proposed by previous research to categorize strict lecithotrophic from incipient histotrophic species. Totals of 236 and 135 ornate wobbegong Orectolobus ornatus and spotted wobbegong Orectolobus maculatus, respectively, were collected from the New South Wales commercial fishery between June 2003 and May 2006. Eight pregnant gulf wobbegong Orectolobus halei were also recorded outside the sampling period for the first time. The three species were reproductively synchronous with a gestation of c. 10-11 months. Embryos started to be macroscopically visible during January and external yolk sacs were fully absorbed by June to July when embryos were c. 200 mm total length (L(T) ). Internal yolk sacs were first observed during April to May when embryos were c. 160 mm L(T) , reached a peak during June and persisted in embryos immediately prior to parturition. The total wet mass from uterine egg to full-term embryos increased by 44-89% and 45-62%, whereas the total organic mass decreased by 32-33% and 26%, for O. ornatus and O. maculatus, respectively, suggesting that these species are strict lecithotrophic yolk-sac viviparous sharks with no maternal nutrient input. A review of the literature identified various issues and suggested that the previously proposed organic mass loss threshold value separating strict lecithotrophic species from incipient histotrophic species might not be appropriate. Instead, it is recommended that a combination of methods (e.g. estimation of organic mass gain or loss between ovarian egg and developed embryo, histology and electron microscopy of the uterus, radio-tracer assay and uterine fluid analysis throughout gestation) is used to discern between strict lecithotrophic and incipient histotrophic species.     

Growth rates of juvenile smalltooth sawfish Pristis pectinata Latham in the western Atlantic

The growth rates of juvenile smalltooth sawfish Pristis pectinata collected in Florida waters between 1999 and 2006 were investigated using length-frequency and tag-recapture data. Stretched total length ( L _ST) data from 144 smalltooth sawfish (690–4960 mm) and 28 recaptures (775–2150 mm) were used for the analyses. Both methods indicated that growth was rapid during the first 2 years after birth. The L _ST increased by 650–850 mm in the first year, and by 480–680 mm in the second year. Data for animals >2200 mm were limited, so growth beyond 2 years of age was uncertain. The von Bertalanffy growth parameters estimated from L _ST frequency data were L _∞= 6000 mm, K = 0·140 year⁻¹ and t ₀=−0·863 years. Growth rates over the size range for which tag-recapture data were available were similar to that from L _ST frequency data. The growth rates reported are substantially faster than those previously assumed for this species and may have important implications for the recovery of this endangered species. There are conflicting data regarding the growth rates of older P. pectinata which need to be resolved with more data from the wild population before a complete understanding of the conservation implications can be obtained.     

徽水河宽鳍的年龄、生长和繁殖

认识鱼类的生活史特征及其对生态环境变化的响应,是鱼类物种保护与资源合理利用的基础。于2009年5月至2010年4月研究了黄山地区徽水河中宽鳍鱲(Zacco platypus)的年龄、生长和繁殖。共采集标本352尾,雌雄性比为0.49∶1,与1∶1差异显著。以鳞片为年龄鉴定材料,雌、雄个体的最大寿命均为3龄;年轮主要形成于3月份。全长和体重呈幂函数关系,两性间无显著性差异,关系式表达为W=6×10–6L3.10;全长和鳞径呈线性关系,且两性间差异显著,关系式分别表达为L♀=29.58R+38.84和L♂=33.17R+34.99;2龄个体的退算全长在雌、雄两性间无显著性差异。繁殖时间为4—7月份;2龄时达50%初次性成熟,其个体全长为98.22(雌)和105.69 mm(雄);绝对繁殖力为(758±362)卵粒,相对繁殖力为(77.38±22.15)卵粒/g。同已有的少量研究资料相比较,徽水河宽鳍鱲的年龄结构较北京地区种群的相对简单,个体生长较同为黄山地区的浦溪河种群相对快速,这种生活史特征差异可能是生态环境空间异质性的作用结果,但有关宽鳍鱲各生活史特征之间的权衡及其对生态环境的响应还有待于进一步研究。