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

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.

1965 ◽  
Vol 22 (3) ◽  
pp. 695-711 ◽  
Author(s):  
Vernon C. Applegate ◽  
M. L. H. Thomas

The sex, length, and weight were determined of nearly all recently transformed sea lampreys migrating downstream in the Carp Lake River, Michigan, in the fall, winter, and spring of 1960–61. Similar data were collected from samples of an earlier run in the Carp Lake River and of runs in three other tributaries of Lakes Huron and Michigan. The sex ratio of the 1960–61 migrants in the Carp Lake River was 324 males:100 females. Sex ratios of migrants in the other runs varied from 77 to 86 males:100 females. The high proportion of males in the 1960–61 run in the Carp Lake River is attributed to the effective prevention of recruitment of sea lampreys in the river and transformation of the females at an earlier age than is characteristic of the males. A near equal sex ratio among recently transformed migrants is considered normal for the species. The sex composition of a run changed during the period of migration. The proportion of males among the migrants was greatest at the beginning of the run and declined steadily thereafter. The average size was smaller for males than for females. Differences in the mean lengths and weights of the sexes were statistically significant. The length–weight relation differed for the sexes and showed a slower rate of increase of weight with increase in length than is characteristic of other stages of the animals' life cycle. Seasonal changes in the length–weight relation had a trend toward lower weights among the migrants coming downstream in the later months of the run.


1980 ◽  
Vol 37 (11) ◽  
pp. 1802-1810 ◽  
Author(s):  
W. A. Pearce ◽  
R. A. Braem ◽  
S. M. Dustin ◽  
J. J. Tibbles

Sea lamprey (Petromyzon marinus) are established in each of the several discrete areas in the St. Lawrence River system between Lake Huron and the Moses–Saunders Power Dam (160 km below Lake Ontario) except for the Niagara River between Niagara Falls and Lake Ontario. However, chemical lampricide treatments are being used to control these populations only in Lake Ontario. Experimental introductions of trout and salmon in Lake Ontario between 1968 and 1971 were not successful. Survival was limited and the number of sea lamprey attack marks on the fish that did mature was very high. After the first round of lampricide treatments of most sea lamprey producing tributaries in 1972, survival of fish improved and lamprey attacks declined. Studies are being completed to determine the desirability of including Oneida Lake in the treatment schedule to prevent recruitment of sea lampreys from this area to Lake Ontario and to improve the fish populations of Oneida Lake. Treatment of Lake Champlain also is being studied by management agencies concerned with its fisheries. Lake St. Clair and Lake Erie and connecting waters, the Finger Lakes, and the St. Lawrence River below Lake Ontario do not appear to have sea lampreys in the numbers necessary to cause unacceptable levels of predation on fish populations and are not being considered for inclusion in the Great Lakes Fishery Commission control program at this time.Key words: sea lamprey, predation, abundance, history, Erie, Ontario, Oneida, Finger Lakes, Champlain


1980 ◽  
Vol 37 (11) ◽  
pp. 1989-2006 ◽  
Author(s):  
Everett Louis King Jr.

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


1987 ◽  
Vol 65 (4) ◽  
pp. 1021-1027 ◽  
Author(s):  
Christian Lydersen ◽  
Ian Gjertz

Samples were taken from 284 ringed seals (Phoca hispida) in the Svalbard area during April–July 1981 and March–April 1982. The age of 283 seals was determined by reading annuli in the cementum of the canine teeth. The mean age of the males was 11.3 years, and of the females, 14.9 years. Females were found to be significantly older than males. The mean length of sexually mature ringed seals was 128.9 cm for both sexes. The mean weight of adult males and females was 53.5 and 61.4 kg, respectively. Females were found to be significantly heavier than males. The sex ratio was 47.8% males and 52.2% females. Studies of microscopic sections of testis and epididymis from ringed seal males showed that 63, 75, and 80% of 5-, 6-, and 7-year-old animals, respectively, were sexually mature. The weights of testis and epididymis, diameters of tubuli, and the size of testis all showed a marked increase in the 5-year age-class. Macroscopic sections of ovaries from ringed seal females showed that 20, 60, and 80% of 3-, 4-, and 5-year-old animals, respectively, were sexually mature. The size of the ovaries showed a marked increase in the 5-year age-class. The ovulation rate of ringed seals from Svalbard was calculated to be 0.91.


1995 ◽  
Vol 52 (6) ◽  
pp. 1257-1264 ◽  
Author(s):  
Roger A. Bergstedt ◽  
William D. Swink

We used lengths and weights of 2367 live parasitic-phase sea lampreys (Petromyzon marinus) collected from Lake Huron, 1984–1990, to calculate their mean size at half-month intervals. Growth in weight was linear during June through September; increments averaged 11.1 g per half month. Growth increased sharply in October to several times the summer rate. We speculate that the increase in growth in October is explained partly by water temperature and partly by an increase in appetite related to the onset of gonadal development. The greater compression of biomass accumulation in autumn than has been previously demonstrated better explains the autumn pulse of sea lamprey induced host mortality. Based on the seasonal pattern of growth and on recaptures of marked sea lampreys, we conclude that landlocked individuals grow to adult size and mature in one parasitic growth year. Regressions of weight (grams) on total length (millimetres) differed significantly among months, and the season of collection must be considered in predicting weight from length.


2008 ◽  
Vol 4 (6) ◽  
pp. 659-662 ◽  
Author(s):  
John Waldman ◽  
Cheryl Grunwald ◽  
Isaac Wirgin

Anadromous fishes are believed to make regular circuits of migration in the sea before homing to their natal rivers. Sea lamprey Petromyzon marinus is an anadromous fish that is an exception to this life-history pattern. It also differs from other anadromous fishes in that its adult phase is parasitic, a feeding strategy that should make homing problematic for lamprey cohorts that become widely dispersed through transport by the diverse hosts they parasitize. We sequenced a portion of the mitochondrial DNA control region from sea lampreys collected from 11 North American east coast rivers to test for genetic evidence of homing. There were no significant differences ( Χ 2 =235.1, p =0.401) in haplotype frequencies among them, with almost 99 per cent of haplotypic diversity occurring within populations. These findings, together with concordant genetic results from other geographical regions and ancillary information on pheromonal communication, suggest that sea lamprey does not home but rather exhibits regional panmixia while using a novel ‘suitable river’ strategy to complete its life cycle.


2011 ◽  
Vol 68 (3) ◽  
pp. 523-533 ◽  
Author(s):  
Lance A. Vrieze ◽  
Roger A. Bergstedt ◽  
Peter W. Sorensen

Stream-finding behavior of adult sea lamprey ( Petromyzon marinus ), an anadromous fish that relies on pheromones to locate spawning streams, was documented in the vicinity of an important spawning river in the Great Lakes. Untreated and anosmic migrating sea lampreys were implanted with acoustic transmitters and then released outside the Ocqueoc River. Lampreys swam only at night and then actively. When outside of the river plume, lampreys pursued relatively straight bearings parallel to the shoreline while making frequent vertical excursions. In contrast, when within the plume, lampreys made large turns and exhibited a weak bias towards the river mouth, which one-third of them entered. The behavior of anosmic lampreys resembled that of untreated lampreys outside of the plume, except they pursued a more northerly compass bearing. To locate streams, sea lampreys appear to employ a three-phase odor-mediated strategy that involves an initial search along shorelines while casting vertically, followed by river-water-induced turning that brings them close to the river’s mouth, which they then enter using rheotaxis. This novel strategy differs from that of salmonids and appears to offer this poor swimmer adaptive flexibility and suggests ways that pheromonal odors might be used to manage this invasive species.


1978 ◽  
Vol 56 (4) ◽  
pp. 561-570 ◽  
Author(s):  
I. C. Potter ◽  
G. M. Wright ◽  
J. H. Youson

A study has been made of metamorphosis in anadromous sea lampreys in New Brunswick between 1973 and 1976. The stages (1–7) commence with the recently described 'prometamorphic ammocoete' (Youson, J. H., G. M. Wright, and E. C. Ooi. 1977. The timing of changes in several internal organs during metamorphosis of anadromous larval lamprey Petromyzon marinus L. Can. J. Zool. 55: 469–473.) and conclude with one similar to the newly metamorphosed landlocked sea lamprey (Manion, P. J., and T. M. Stauffer. 1970. Metamorphosis of the landlocked sea lamprey, Petromyzon marinus. J. Fish. Res. Board Can. 27: 1735–1746.). Most of the marked quantitative changes exhibited by certain regions of the body can be directly related to adaptations for suctorial feeding, increased activity, and a predaceous mode of life. Reductions in the prebranchial length are almost certainly associated with changes in the pharyngeal basket which facilitate alterations in the direction of the respiratory water flow. The timing of metamorphosis was remarkably synchronous both within and between years, representatives of the earliest stages (1–2) being found only between July 7 and 28 while after September 14 only stage 7 animals were caught. During metamorphosis the lengths of the animals changed little whereas their weights declined significantly. The weights and condition factors of stage 1–2 animals were significantly greater than those of larvae of comparable length. This feature, presumably related to lipid accumulation at the end of larval life, is discussed in the context of factors influencing the onset of metamorphosis.


1980 ◽  
Vol 37 (11) ◽  
pp. 1895-1905 ◽  
Author(s):  
P. A. Gllderhus ◽  
B. G. H. Johnson

The chemicals 3-trifluoromethyl-4-nitrophenol (TFM) or a combination of TFM and 2′,5-dichloro-4′-nitrosalicylanilide (Bayer 73) have been used to control the sea lamprey (Petromyzon marinus) in the Great Lakes for about 20 yr. These chemicals cause some mortalities of Oligochaeta and Hirudinea, immature forms of Ephemeroptera (Hexagenia sp.), and certain Trichoptera, Simuliidae, and Amphibia (Necturus sp.). The combination of TFM and Bayer 73 may affect some Pelecypoda and Gastropoda, but its overall effects on invertebrates are probably less than those of TFM alone. Granular Bayer 73 is likely to induce mortalities among oligochaetes, microcrustaceans, chironomids, and pelecypods. No evidence exists that the lampricides have caused the catastrophic decline or disappearance of any species. The overall impact of chemical control of sea lampreys on aquatic communities has been minor compared with the benefits derived.Key words: sea lamprey control, Great Lakes, TFM, Bayer 73, aquatic plants, invertebrates, amphibians


1996 ◽  
Vol 74 (12) ◽  
pp. 2206-2210 ◽  
Author(s):  
Kelly K. Tsioros ◽  
John A. Holmes ◽  
John H. Youson

Iron (Fe) concentration was measured in unfertilized eggs, embryos, prolarvae, and young larvae (up to day 56) of sea lampreys (Petromyzon marinus) raised in two substrates to determine (i) the importance of maternal transfer to Fe accumulation in sea lampreys and (ii) the influence of substrate on Fe uptake in young larvae. Unfertilized eggs contained about 35 ng of Fe, supporting the maternal transfer hypothesis. There were no significant changes in Fe concentration in developing embryos and prolarvae after hatching. Young larvae rapidly accumulated Fe from their burrowing substrate and the amount accumulated depended on the amount of Fe in the substrate. Since this rapid accumulation coincides with the beginning of exogenous feeding, as well as burrowing, environmental sources of Fe appear to be important contributors to Fe body burdens in larval sea lampreys.


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