GLORIA

GEOMAR Library Ocean Research Information Access

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Competitive ability and the potential for lotteries among territorial reef fishes (1995)
    Springer
    Oecologia 103 (1995), S. 180-190 
    Details
    ISSN: 1432-1939
    Keywords: Coral reef fish ; Lottery coexistence ; Competitive ability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Stegastes diencaeus and S. dorsopunicans are mutually territorial Caribbean damselfishes. S. diencaeus is larger, grows faster and lives longer than S. dorsopunicans. S. diencaeus is a habitat specialist that shares its primary habitat mainly with S. dorsopunicans. Field manipulations show that both S. diencaeus and S. dorsopunicans readily take over living space from smaller, but not larger, heterospecific neighbors. Natural changes in the use of living space by both species occur frequently and adult S. diencaeus often aggressively usurp the living areas of smaller S. dorsopunicans. Lunar and seasonal patterns of juvenile recruitment by S. diencaeus and S. dorsopunicans are similar. Large size bestows competitive superiority on S. diencaeus by giving its adults a superior ability to aggressively acquire living space, and by enabling its juveniles to quickly escape the period when they lack a size advantage. Hence they spend much of their lives as competitive dominants. There is no evidence that competitive advantages arising from large size are offset either by other adult attributes or by differences in temporal patterns of recruitment that affect priority of access to space. The lottery hypothesis for species coexistence relies on patterns of abundance being determined by patterns of recruitment to vacant space because different species have equal space-holding abilities. These data show that the existence of such a mechanism is doubtful.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00329078
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Does gonad structure reflect sexual pattern in all gobiid fishes? (1994)
    Springer
    Environmental biology of fishes 41 (1994), S. 301-309 
    Details
    ISSN: 1573-5133
    Keywords: Ontogeny ; Protogyny ; Gobiosoma ; Gobiidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis In immature and adult females of protogynous gobies, small distinctive masses of cells associated with the ovarian wall develop into testis-associated glandular structures during sex change. These precursive accessory gonadal structures, or pAGS, have been found in females of known protogynous goby species, but not among gonochoric goby species, suggesting that their presence can be used as a species-specific indicator of protogyny within the family. However, a detailed examination of a developmental series of ovaries in two gonochoric species,Gobiosoma illecebrosum andG. saucrum, revealed the presence of a gonadal feature previously thought to be restricted to protogynous gobies. Among immature females of both species, pAGS-like structures having a similar appearance and placement as functional pAGS of protogynous gobies were found. In femaleG. illecebrosum, the size of these structures among immatures progressively decreased with maturation and were absent in all but the smallest adult females. A similar pattern was evident in a small sample ofG. saucrum. Population demography based on field collections showed thatG. illecebrosum exhibits sex ratios and male and female size-frequency distributions typical of gonochores and laboratory experiments indicated that final sexual identity was unaffected by social environment during the juvenile period. Thus, the presence of pAGS in juvenile femaleG. illecebrosum is not related to an ability to change sex at that ontogenic interval. Whether the transient pAGS observed here are vestiges of an ancestral protogynous condition is unknown. Based on their presence among immatures in two gonochore gobies, however, only the presence of pAGS in adult females should be used to predict protogyny among gobies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02197851
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Does gonad structure reflect sexual pattern in all gobiid fishes? (1994)
    Springer
    Environmental biology of fishes 41 (1994), S. 301-309 
    Details
    ISSN: 1573-5133
    Keywords: Ontogeny ; Protogyny ; Gobiosoma ; Gobiidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis In immature and adult females of protogynous gobies, small distinctive masses of cells associated with the ovarian wall develop into testis-associated glandular structures during sex change. These precursive accessory gonadal structures, or pAGS, have been found in females of known protogynous goby species, but not among gonochoric goby species, suggesting that their presence can be used as a species-specific indicator of protogyny within the family. However, a detailed examination of a developmental series of ovaries in two gonochoric species,Gobiosoma illecebrosum andG. saucrum, revealed the presence of a gonadal feature previously thought to be restricted to protogynous gobies. Among immature females of both species, pAGS-like structures having a similar appearance and placement as functional pAGS of protogynous gobies were found. In femaleG. illecebrosum, the size of these structures among immatures progressively decreased with maturation and were absent in all but the smallest adult females. A similar pattern was evident in a small sample ofG. saucrum. Population demography based on field collections showed thatG. illecebrosum exhibits sex ratios and male and female size-frequency distributions typical of gonochores and laboratory experiments indicated that final sexual identity was unaffected by social environment during the juvenile period. Thus, the presence of pAGS in juvenile femaleG. illecebrosum is not related to an ability to change sex at that ontogenic interval. Whether the transient pAGS observed here are vestiges of an ancestral protogynous condition is unknown. Based on their presence among immatures in two gonochore gobies, however, only the presence of pAGS in adult females should be used to predict protogyny among gobies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00023819
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...