摘要:

AbstractThe ecology and life histories ofOrconectes rusticus rusticus(GIRARD) and Cambarus tenebrosus HAY were investigated in a spring stream, Doe Run, Meade County, Kentucky, from September 1962 through September 1964. Differences in ecology of these species were most clearly seen in their habitat preferences and distributions in the stream, their feeding habits, responses to temperature, and infestations by an harpacticoid copepodAttheyella carolinensisCHAPPUIS, and in other life history phenomena, particularly with regard to reproduction and growth.Cambarus tenebrosuswas most abundant in the constant temperature areas of the headwaters of Doe Run.Orconectes r. rusticuswas found only in the lower three‐fourths of the stream. Water temperatures in the headwater area may have been too low (12 — 14 C) for optimal growth of the crayfish had it existed there. Adults ofC. tenebrosuswere primarily hypogean, but young and subadults frequented the open stream environment.Orconectes r. rusticuswas primarily an open stream inhabitant, and was sympatric withC. tenebrosussubadults and young in the downstream areas. WhenC. tenebrosusoccurred in the open environment, it was most abundant in association with vegetation, and hence, was more heavily infested withA. carolinensisthanO. r. rusticus.Detritus, mainly from fallen leaves and marl grazings, apparently formed the most important component of the diet ofO. r. rusticus.Vascular plants, mainly fallen leaves from the riparian vegetation, constituted the main portion of the diet ofC. tenebrosus;filamentous algae were widely used where and when they were present.Orconectes r. rusticuseggs hatch in May. These hatchlings become mature in 15 months and females oviposit after 22 – 24 months from March —May. Sexual maturity is attained at a carapace length of about 18 mm; maximum size is 45 mm. Most animals die after about 2.5 years; however, some live for three years. Molting activity ceases in winter.Cambarus tenebrosusyoung hatch in July and August. Most hatchlings remain in the burrows until October and November at which time they emerge in response to dominance behavior. Growth occurs throughout the winter months, and sexual maturity is attained in 20 – 22 months when the crayfish are about 40 mm in carapace length. Mature females oviposit during June and July after about 22–23 months, and probably again after 34–35 months. Mating occurs during the winter and spring. In Doe Run, maximum size attained is 65 mm carapace length.Cambarus tenebrosusprobably lives for 3

ISSN:0020-9309    

DOI:10.1002/iroh.19680530502

出版商:Akademie Verlag, Berlin    

年代:1968

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19680530503

出版商:Akademie Verlag, Berlin    

年代:1968

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19680530504

出版商:Akademie Verlag, Berlin    

年代:1968

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19680530505

出版商:Akademie Verlag, Berlin    

年代:1968

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19680530506

出版商:Akademie Verlag, Berlin    

年代:1968

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19680530501

出版商:Akademie Verlag, Berlin    

年代:1968

数据来源: WILEY