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The effects of maximum, minimum, and slot length limits on the sizes and relative abundance of northern pike Esox lucius were evaluated in 22 Minnesota lakes. The regulations were implemented in 1989-1998 and lasted 9-15 years. As preregulation information was available back to the 1970s, the evaluation periods covered 21-37 years. Comparisons were made with reference populations from 47 ecologically similar lakes during the same extended period. Although the regulations did not achieve management objectives in every lake, the broader-scale, statewide finding was that they improved the size structure of northern pike populations but produced no consistent trends in relative abundance. The improvements were detected against the backdrop of reference populations that initially appeared to have similar sizes and relative abundances. Maximum length limits protecting fish over 20, 22, and 24 in produced significant long-term increases in the percentages of northern pike 24 in and longer and 30 in and longer compared with the reference populations. Lakes with 30-in minimum length limits had increased percentages of northern pike 20 in and longer, but the improvements did not carry over to fish 30 in and longer. A mix of slot length limits produced results that are more difficult to interpret but generally improved size structure. A metaanalysis incorporating all of the length regulations indicated that the changes in northern pike size structure in regulated lakes were very large for an ecological experiment. Length limits protected large northern pike, with the expectation that lower yields were an acceptable trade-off for producing larger fish for recreational fisheries. This study reveals the range and magnitude of responses we can reasonably expect from length limits as well as the substantial value of conserving large fish when the goal is improved population size structure. [ABSTRACT FROM AUTHOR]

Fisheries professionals charged with managing muskellunge Esox masquinongy frequently seek population information that requires the ability to identify cohorts as well as individuals; hence, reliable tagging methods are needed. Our approach was to simultaneously assess multiple marking techniques on different life stages of muskellunge over short and long time scales. We evaluated the short-term detection of visible implant elastomer (VIE) and passive integrated transponder (PIT) tags in muskellunge fingerlings in experimental ponds. We compared survival (relative to that of control fish) and tag retention for two PIT tagging locations (the cheek and dorsal musculature) and one VIE location (the jaw). Overwinter survival did not differ between tagged and untagged fish (84-98%), but overwinter PIT tag retention was lower for the cheek (92%) than the dorsal musculature (100%). We also fin-clipped and VIE-tagged (jaw) 1,651 muskellunge fingerlings from 1997 to 2002 to evaluate long-term tag retention in a broodstock lake. In addition, 125 adult muskellunge were captured and PIT-tagged from 2003 to 2006. Muskellunge were sampled annually with trap nets and electrofishing during spring and fall. Only 2 VIE tags were detected in adults marked as fingerlings. The proportion of PIT-tagged adults recaptured ranged from 52% to 84% during the sampling period. Our results indicate that both VIE and PiT tags are viable short-term marks for muskellunge fingerlings, while PIT tags appear to be reliable long-term tags when implanted in the dorsal musculature of adults. [ABSTRACT FROM AUTHOR]

The article focuses on the published taxonomic accounts of Neoechinorhynchus tenellus from Esox lucius Linnaeus and Sander vitreus. Its original type material was studied and found that their present state are little use for clarifying characters. The revised description includes trunk of males and females that is widest in anterior, the lateral anterior hooks which are marked larger, and the middle and posterior hooks with discoidal bases.

Public opinion plays an important part in the successful development of a fisheries management plan. We used a mail questionnaire to survey 1,400 anglers who fish for muskellunge Esox masquinongy in Wisconsin. The survey included defined groups of muskellunge anglers separated by muskellunge club affiliation and geographic location and general anglers selected from a random sample of angler license sales. The survey questions were designed to obtain opinions regarding muskellunge fishery and trophy management in Wisconsin in terms of angling behaviors, regulation options, and perceived problems. All anglers generally preferred fishing with artificial lures and practiced the voluntary live release of legal-length muskellunge. Muskellunge anglers considered a trophy muskellunge to be at least 40 in long, with a preferred length of 50 in or longer. Muskellunge anglers also supported regulations for muskellunge that were based on a water's biological potential, along with increased restrictions on regulations such as minimum length limits. General anglers were less supportive of restrictive regulations and were more likely to keep a legal muskellunge for consumptive purposes. The greatest perceived problems with muskellunge fishing were Native American spearing and conflicts with users of speedboats and jet skis. Opinion surveys such as this can help in formulating management strategies that satisfy most anglers within biological limits. [ABSTRACT FROM AUTHOR]

The data concerning epizootology of the tumor disease in Esox lucius L. in the Kiev Reservoir in the years 2000-2001 arc provided. No clear seasonal regularities in distribution of neoplasms over the reservoir were noted, whereas the age features of the disease occurrence can be revealed. Three stages in development of tumors and pathological processes are distinguished. [ABSTRACT FROM AUTHOR]