Metamorphosis of the Landlocked Sea Lamprey, Petromyzon marinus

1970 ◽  
Vol 27 (10) ◽  
pp. 1735-1746 ◽  
Author(s):  
Patrick J. Manion ◽  
Thomas M. Stauffer
Keyword(s):  
Petromyzon Marinus ◽  
Sea Lamprey ◽  
Natural Conditions ◽  
Mouth Region ◽  
Total Length ◽  
The Mean

The external metamorphosis of the sea lamprey was divided into four stages, based primarily on the condition of the mouth: mouth reduced, mouth fused, mouth enclosed, and mouth elongated. During metamorphosis, the eye enlarged greatly, the snout and mouth region changed from a fleshy hood enclosing a sieve apparatus to a large sucking disc, the nasopore membrane and the branchial area shrank, the branchiopores changed in shape, the general color changed from dark brown and yellow to an intense blue-black dorsally and white ventrally, and the total length increased. Metamorphosis began in early to mid-July and did not take place after August. The duration of external metamorphosis was about 3 months for lampreys transforming under natural conditions. The mean lengths of metamorphosing lampreys from tributaries of lakes Superior and Michigan were 145 and 136 mm, respectively.

Sex Ratios and Lengths of Adult Sea Lampreys (Petromyzon marinus) from a Lake Ontario Tributary

1974 ◽  
Vol 31 (1) ◽  
pp. 122-124 ◽  
Author(s):  
I. C. Potter ◽  
F. W. H. Beamish ◽  
B. G. H. Johnson
Keyword(s):  
Narrow Range ◽  
Sex Ratios ◽  
Petromyzon Marinus ◽  
Lake Ontario ◽  
Sea Lamprey ◽  
Adult Males ◽  
Sea Lampreys ◽  
Males And Females ◽  
The Mean ◽  
Humber River

The mean lengths of adult males and females of the sea lamprey (Petromyzon marinus) migrating into the Humber River from Lake Ontario in each of the years 1968–1972 varied little, and were similar to those found by other workers in recently established populations in the upper lakes. In contrast, the ratio of males to females, which lay within the narrow range of 1:1 to 1.26:1, was similar to those reported for long-established populations.

Oxygen Consumption of Adult Petromyzon marinus in Relation to Body Weight and Temperature

1973 ◽  
Vol 30 (9) ◽  
pp. 1367-1370 ◽  
Author(s):  
F. W. H. Beamish
Keyword(s):  
Body Weight ◽  
Oxygen Consumption ◽  
Regression Coefficient ◽  
Petromyzon Marinus ◽  
Sea Lamprey ◽  
Active Oxygen ◽  
Fixed Weight ◽  
Proportionate Change ◽  
The Mean

The logarithm of standard oxygen consumption of adult Petromyzon marinus increased linearly with the logarithm of weight at each of 5, 10, and 15 C. The proportionate change in standard oxygen consumption for a given change in temperature was independent of size, the mean regression coefficient being 0.949. Standard oxygen consumption for a sea lamprey of fixed weight increased from 52.7 to 124.0 mg/kg per hr over the range 5–20 C with the greatest changes occurring between 10–15 C, 64.5–114.3 mg/kg per hr. Active oxygen consumption was estimated for a few individuals at 10 C and found to be 475.5 mg/kg per hr, within the range reported for teleosts.

Lethal Temperatures of the Developmental Stages of the Sea Lamprey, Petromyzon marinus L.

1963 ◽  
Vol 20 (2) ◽  
pp. 483-490 ◽  
Author(s):  
R. W. McCauley
Keyword(s):  
High Temperature ◽  
Developmental Stages ◽  
Petromyzon Marinus ◽  
Temperature Characteristic ◽  
Sea Lamprey ◽  
Natural Conditions ◽  
Thermal Requirements ◽  
Lethal Temperatures

Of all stages of the sea lamprey, the eggs have the most exacting thermal requirements. The range of constant temperatures necessary for successful hatching is narrow, being 15–25 °C. This range may be extended to 12–26 °C and possibly beyond, if the eggs have developed to the head stage before they encounter temperature extremes.The ability to withstand high temperature characteristic of the post-embryonic stages of the species appears shortly before or after hatching.The role of temperature in the development of eggs under natural conditions is discussed.

Effect of density and individual variation on growth of sea lamprey (Petromyzon marinus) larvae in the laboratory

1992 ◽  
Vol 70 (1) ◽  
pp. 184-188 ◽  
Author(s):  
Scott P. Murdoch ◽  
Margaret F. Docker ◽  
F. William H. Beamish
Keyword(s):  
Sex Ratio ◽  
Standard Error ◽  
Individual Variation ◽  
Petromyzon Marinus ◽  
Sea Lamprey ◽  
High Density ◽  
Initial Length ◽  
Subcutaneous Injections ◽  
Length Standard ◽  
The Mean

Sea lamprey (Petromyzon marinus) larvae were individually marked with subcutaneous injections of latex dye and maintained in the laboratory from June 1988 to February 1989 at tank densities of 10, 50, and 100 larvae per 0.3 m2 of substrate. Growth, measured as change in total length and weight, varied widely among individuals: change in length during a 3-month period differed by as much as 17.0 mm within one tank of 10 larvae. Despite individual variation, growth decreased significantly with increasing density: the mean increase in length (± standard error) over the 8-month period was 17.3 ± 3.0, 4.3 ± 1.5, and −1.4 ± 1.0 mm at low, medium, and high density, respectively. The initial length or the sex of an individual at the end of the experiment had little or no effect on growth. Mortality was negligible (1.6%), and could not be significantly correlated with density, size, or sex. The overall sex ratio was 33% male, and did not vary significantly with tank or density.

scholarly journals The differential transmissibility of myxoma virus strains of differing virulence grades by the rabbit flea Spilopsyllus cuniculi (Dale)

1975 ◽  
Vol 75 (2) ◽  
pp. 237-247 ◽  
Author(s):  
A. R. Mead-Briggs ◽  
J. A. Vaughan
Keyword(s):  
Host Resistance ◽  
Oryctolagus Cuniculus ◽  
Selective Advantage ◽  
Myxoma Virus ◽  
Laboratory Studies ◽  
Natural Conditions ◽  
Male And Female ◽  
The Mean ◽  
Virus Strains ◽  
Sampling Times

SUMMARYLaboratory studies showed that few rabbit fleas (Spilopsyllus cuniculi (Dale)) transmitted myxomatosis after removal from wild rabbits (Oryctolagus cuniculus (L)) that had been infected for fewer than 10–12 days, irrespective of the virulence of the myxoma virus strain involved. Rabbits infected with fully virulent (Grade I) strains died within 10–15 days and few fleas from these hosts became infective; averaging all the samples taken, 12% of the fleas were infective. Also, few fleas acquired infectivity on individual rabbits which recovered from infection with attenuated strains; the mean was 8% infective. Rabbits which died between 17 and 44 days after infection had higher proportions of infective fleas at all sampling times; the mean was 42% infective. Male and female fleas transmitted virus with equal efficiency.For rabbits infected with any of the attenuated virus strains the mean percentage of infective fleas was inversely related to the survival time of the host. Rabbits infected with moderately attenuated strains (Grades IIIA and IIIB) had, on average, the highest proportion of infective fleas; hence such strains have a selective advantage and have become predominant under natural conditions in Britain. The changes that might occur if there is an increase in host resistance to myxomatosis are discussed.

Classification of Sea Lamprey (Petromyzon marinus) Attack Marks on Great Lakes Lake Trout (Salvelinus namaycush)

1980 ◽  
Vol 37 (11) ◽  
pp. 1989-2006 ◽  
Author(s):  
Everett Louis King Jr.
Keyword(s):  
Great Lakes ◽  
Lake Trout ◽  
Petromyzon Marinus ◽  
Attachment Site ◽  
Sea Lamprey ◽  
Salvelinus Namaycush ◽  
Oral Disc ◽  
Field Assessment ◽  
Sea Lampreys

Criteria for the classification of marks inflicted by sea lamprey (Petromyzon marinus) into nine categories were developed from laboratory studies in an attempt to refine the classification system used in field assessment work. These criteria were based on characteristics of the attachment site that could be identified under field conditions by unaided visual means and by touching the attachment site. Healing of these marks was somewhat variable and was influenced by the size of lamprey, duration of attachment, severity of the wound at lamprey detachment, season and water temperature, and by other less obvious factors. Even under laboratory conditions staging of some wounds was difficult, especially at low water temperatures. If these criteria are to be used effectively and with precision in the field, close examination of individual fish may be required. If the feeding and density of specific year-classes of sea lampreys are to be accurately assessed on an annual basis, close attention to the wound size (as it reflects the size of the lamprey's oral disc) and character of wounds on fish will be required as well as consideration of the season of the year in which they are observed.Key words: sea lamprey, attack marks, lake trout, Great Lakes

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