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Czech First Fishing Licence Knowledge Verification: freshwater angling study materials
Czech First Fishing Licence Knowledge Verification: freshwater angling study resources

Czech First Fishing Licence Knowledge Verification: freshwater angling practice questions

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Question 1Pravni Predpisy A Etika

An angler has a valid Czech state fishing licence but no permission covering the intended district. What does the licence alone establish?

  1. It authorizes fishing on every privately managed district.
  2. It removes the need to check district boundaries.
  3. It overrides all conditions set by the district user.
  4. It does not replace the required district angling permission. Correct answer.

Explanation

The state fishing licence and the permission covering a district have different functions. A licence alone does not establish the required permission for the actual place or override applicable conditions.

Question 2Pravni Predpisy A Etika

A person has joined a fishing association but has not obtained the actual required licence and district permission. Is membership sufficient to begin angling?

  1. Yes, provided no fish are retained.
  2. Yes, if another member lends a catch log.
  3. No; membership is distinct from the required fishing documents. Correct answer.
  4. Yes; paying membership dues supplies every required authorization.

Explanation

Association membership is not itself every statutory and district authorization. The actual licence, permission and applicable conditions must be established; planning to release the catch does not remove them.

Question 3Pravni Predpisy A Etika

A teaching case states a district minimum of 50 cm for a species, stricter than the applicable general minimum. A fish measures 47 cm. Which conclusion follows?

  1. The district minimum applies only after the first retained fish.
  2. It cannot be retained under the stated district minimum. Correct answer.
  3. The lower general minimum always overrides the district condition.
  4. Rounding the length to the nearest ten centimetres permits retention.

Explanation

The case expressly supplies an applicable stricter district condition. A 47 cm fish is below 50 cm and cannot be retained under that condition; no rounding or first-fish exception is supplied.

Question 4Pravni Predpisy A Etika

A navigation app places an angler near a boundary between two Czech districts. What should determine the permission check?

  1. The actual district identity and boundary, checked against authoritative information. Correct answer.
  2. The app pin alone, even when official signs disagree.
  3. The nearest village name regardless of the water boundary.
  4. The district used during the angler’s previous visit elsewhere.

Explanation

District permission concerns the actual place. Use the current authoritative description and relevant signs to resolve the boundary rather than assume an approximate map pin or nearby place name is decisive.

Question 5Pravni Predpisy A Etika

Under the ordinary Czech non-trout daily hours, with no applicable exception, may an angler begin at 03:30 in May?

  1. Yes; daylight alone determines the opening time.
  2. Yes; the ordinary non-trout window begins at 03:00 all year.
  3. Yes; daily hours apply only to retaining fish.
  4. No; the ordinary April–September window begins at 04:00. Correct answer.

Explanation

The ordinary non-trout window for April through September is 04:00 to 24:00. In the stated no-exception case, 03:30 is too early even if daylight or release intentions differ.

Question 6Pravni Predpisy A Etika

An otherwise authorized angler plans to fish a Czech non-trout district at 21:30 in January. No tighter condition or exception applies. Is that within the ordinary daily window?

  1. No; winter angling is universally prohibited for the entire month.
  2. Yes, because a licence removes all daily time limits.
  3. Yes; the ordinary October–March window ends at 22:00. Correct answer.
  4. No; all non-trout winter angling ends at 17:00.

Explanation

The ordinary October through March non-trout window is 05:00 to 22:00. Thus 21:30 falls inside it, although the other applicable conditions still need to be satisfied.

Question 7Pravni Predpisy A Etika

A brown trout is accidentally caught in September during otherwise permitted Czech angling. What follows from its ordinary closed season?

  1. Keep it until the closed season finishes.
  2. Return it carefully rather than retain it. Correct answer.
  3. Retain it because another species may be open.
  4. Retain it whenever it exceeds the minimum length.

Explanation

Brown trout has the ordinary September 1 to April 15 closed season. A fish caught during that protection must be carefully returned; sufficient length does not cancel the closed-season condition.

Question 8Pravni Predpisy A Etika

Under the stated ČRS 2026–27 trout-district conditions, an angler retains a third salmonid. What happens to that day’s angling?

  1. It ends under that condition. Correct answer.
  2. It continues if a different rod is used.
  3. It continues after releasing one earlier retained fish.
  4. It continues if the angler moves to another trout district.

Explanation

The stated ČRS trout-district condition ends daily angling on retention of three salmonids. Changing equipment, moving or inventing an exchange does not create an exception to that condition.

Question 9Pravni Predpisy A Etika

A caught fish is below the applicable minimum retention length. Which action matches the ordinary Czech protection rule?

  1. Transfer it alive to a different pond before release.
  2. Retain it because it took the bait voluntarily.
  3. Keep it whenever the catch log still has empty space.
  4. Return it carefully to the district where it was caught. Correct answer.

Explanation

The protection rule requires careful return of the undersized fish to the district where it was caught. Bait acceptance, available record space and an unauthorized transfer do not change the rule.

Question 10Pravni Predpisy A Etika

Does an ordinary Czech recreational fishing permission alone authorize the holder to use electrical current to capture fish?

  1. Yes, because electrical capture is the same method as spinning.
  2. No; the separate required authority and competence are not supplied by an ordinary permission. Correct answer.
  3. Yes, whenever a handheld battery is used.
  4. Yes, provided all fish will be released.

Explanation

Electrical fishing requires the relevant separate legal and competence conditions. An ordinary recreational permission does not by itself supply them, regardless of the battery type or intended release.

Question 11Pravni Predpisy A Etika

Under the ordinary Czech statutory protection near a fish pass, which proposal is prohibited without an applicable lawful exception?

  1. Angling in the pass or within 50 metres above or below it. Correct answer.
  2. Reading the district description before choosing a place.
  3. Keeping a safe distance from an operating structure.
  4. Checking whether a district condition is tighter than the general rule.

Explanation

The ordinary protection prohibits angling in a fish pass and within 50 metres above and below it. The other choices are checks or precautions, not the prohibited angling proposal.

Question 12Pravni Predpisy A Etika

A caught organism is reliably identified as an invasive alien species on the applicable Union list. What should an angler avoid assuming?

  1. That identification and current applicable rules matter.
  2. That transport and disposal can have separate conditions.
  3. That protected native species have different rules.
  4. That ordinary catch-and-release automatically permits returning it alive. Correct answer.

Explanation

The applicable invasive-species provisions can prohibit returning a caught listed species. Do not apply an automatic release slogan without accurate identification and the actual lawful handling and disposition requirements.

Question 13Pravni Predpisy A Etika

An angler sees fish concentrated by severe pollution and low water. Does this make ordinary opportunistic harvesting automatically permitted?

  1. Yes, if the catch is described as rescue without actual authority.
  2. Yes, provided a non-trout rod limit is respected.
  3. No; the concentration does not cancel protective restrictions. Correct answer.
  4. Yes, because distressed fish have no legal protection.

Explanation

A concentration of fish during harmful conditions does not establish permission for ordinary harvesting. Genuine rescue measures require the actual competent arrangements; a label or rod count is not sufficient.

Question 14Pravni Predpisy A Etika

Before beginning angling under the ČRS conditions, which record belongs in the attendance section?

  1. Only the number of fish released during the previous year.
  2. The actual date and district or relevant subdistrict number. Correct answer.
  3. A forecast of fish that will probably be caught.
  4. The neighbouring district’s number to simplify paperwork.

Explanation

The attendance record identifies the actual date and district, including a relevant subdistrict. Do not substitute expected catches or a convenient neighbouring identifier for the real visit information.

Question 15Pravni Predpisy A Etika

Current Czech law permits an angling permission to be issued in paper or electronic form. Which study claim should therefore be rejected?

  1. Every valid permission must necessarily be a physical paper document. Correct answer.
  2. The actual permission must cover the intended district.
  3. A permission’s validity and conditions remain relevant.
  4. An electronic permission must be used through its actual lawful process.

Explanation

Paper and electronic permissions are both recognized forms under the current framework. The permission must still be valid and applicable, but a universal paper-only assertion is obsolete.

Question 16Pravni Predpisy A Etika

Under the ordinary Czech fly-angling spacing provision, what is the stated minimum between anglers unless they agree otherwise?

  1. 30 metres under every fly-angling arrangement.
  2. No spacing condition of any kind.
  3. A distance determined only by the rod’s price.
  4. 20 metres. Correct answer.

Explanation

The ordinary fly-angling provision states twenty metres unless otherwise agreed. This should not be confused with a remembered thirty-metre figure or treated as removing tighter relevant site conditions.

Question 17Pravni Predpisy A Etika

Under the stated ČRS permission-return condition, when are the required completed permission sections returned to the issuing organization?

  1. Within 15 days after the permission expires. Correct answer.
  2. Only if no fish were caught.
  3. Only when the angler chooses to buy another rod.
  4. Never, because the attendance record has no management purpose.

Explanation

The stated ČRS condition requires return of the relevant sections within fifteen days after expiry. This is identified as that condition, not an invented provision of the decree’s trout-method section.

Question 18Pravni Predpisy A Etika

An undersized fish carries a scientific tag. Under the ordinary Czech tagged-fish provision, which response respects both conditions?

  1. Retain it solely because a tag overrides minimum length.
  2. Transfer it to another district and report the new place as the catch site.
  3. Remove all identification before deciding whether to report it.
  4. Carefully return it and report the relevant tag, catch-place and time information. Correct answer.

Explanation

The fish’s tag does not remove the applicable size protection. The provision combines careful return with reporting relevant identification and catch information, maintaining accurate place and time rather than inventing a new history.

Question 19Pravni Predpisy A Etika

A fish measures 380 mm and an explicitly supplied applicable minimum is 40 cm. Which comparison is correct?

  1. 380 mm is 38 cm, below that minimum. Correct answer.
  2. 380 mm is 380 cm, above that minimum.
  3. 380 mm is exactly 40 cm after automatic legal rounding.
  4. Millimetres and centimetres cannot be converted.

Explanation

Ten millimetres equal one centimetre, so 380 millimetres is 38 centimetres. The fish is below the supplied 40 centimetre minimum; no rounding exception or other retention permission is implied.

Question 20Zpusoby Lovu A Vybaveni

Under the ordinary Czech non-trout spinning rule, how many hooks may one lure have according to its construction?

  1. Any number if the total lure mass is low.
  2. Three treble hooks plus unlimited additional single hooks.
  3. At most three hooks, which may be single, double or treble. Correct answer.
  4. At most two hooks under every spinning rule.

Explanation

The non-trout spinning provision allows a lure to have at most three hooks according to construction. Hook form does not turn that maximum into an unlimited additional allowance; tighter conditions can still apply.

Question 21Zpusoby Lovu A Vybaveni

Under the ordinary Czech trout-district spinning rule from September 1 to November 30, which lure-hook arrangement meets the stated hook condition?

  1. Three treble hooks.
  2. One single hook. Correct answer.
  3. One treble hook.
  4. Two single hooks.

Explanation

The autumn trout-district spinning provision specifies one single hook. This is narrower than the ordinary non-trout lure arrangement and does not independently settle every other district condition.

Question 22Zpusoby Lovu A Vybaveni

For ordinary non-trout float or bottom angling, which of these arrangements matches the stated general terminal-rig option?

  1. No more than two rods, each with at most two single-hook leaders. Correct answer.
  2. Three rods if each has one single hook.
  3. Two rods with unlimited single-hook leaders.
  4. One rod with any number of treble hooks all year.

Explanation

The ordinary provision permits no more than two rods and includes the option of up to two single-hook leaders on each. Other rig options and seasonal restrictions have their own conditions.

Question 23Zpusoby Lovu A Vybaveni

An angler is spinning with one rod on a Czech non-trout district. May another baited rod remain set under the ordinary spinning rule?

  1. Yes, if the other rod has a bite alarm.
  2. Yes, if the other rod is shorter.
  3. Yes, because spinning never counts toward rod limits.
  4. No; another rod is not set while spinning. Correct answer.

Explanation

The spinning rule specifies one held rod and no other rod set. A bite alarm, rod length or a personal classification of the method does not establish an exception.

Question 24Zpusoby Lovu A Vybaveni

A fly imitation is fitted with a rotating blade that increases attraction. How can that affect its treatment under the Czech method definitions?

  1. It makes the lure a permitted live baitfish.
  2. It proves that three rods may be used simultaneously.
  3. It can bring the arrangement under the spinning definition. Correct answer.
  4. It automatically removes all method restrictions.

Explanation

The Czech definitions can treat fly angling with a movement-attracting rotating blade as spinning. The actual construction matters, so ordinary fly-method assumptions cannot automatically be retained.

Question 25Zpusoby Lovu A Vybaveni

A rod’s manufacturer specifies a casting range up to 40 g. A proposed loaded feeder weighs 55 g. What is the appropriate conclusion?

  1. It is within range because the empty feeder weighs less.
  2. Casting faster makes the extra mass irrelevant.
  3. A stronger line automatically raises the rod’s specified limit.
  4. It exceeds that stated range; choose suitable equipment or a compliant load. Correct answer.

Explanation

The complete casting load matters, including the feeder’s contents. Fifty-five grams exceeds the stated 40 g maximum; a different line or faster cast does not alter that specification.

Question 26Zpusoby Lovu A Vybaveni

What is the principal function of an appropriately set reel drag during playing a fish?

  1. To lock every moving reel component permanently.
  2. To replace the need for a suitable landing method.
  3. To allow controlled line release under tension. Correct answer.
  4. To make line strength unlimited.

Explanation

A reel drag allows controlled release when the tension reaches its setting. It helps manage the load but cannot eliminate line, knot, rod or landing limitations.

Question 27Zpusoby Lovu A Vybaveni

Compared with a stretchy nylon line, low-stretch braid generally changes which part of tackle behavior?

  1. It makes the rod’s power and line rating irrelevant.
  2. It transmits tension changes with less stretch cushioning. Correct answer.
  3. It guarantees better abrasion resistance on every rock.
  4. It prevents all hook pulls regardless of drag setting.

Explanation

Lower stretch changes bite transmission and cushioning of sudden loads. It does not guarantee universal abrasion resistance or eliminate the need to match drag, rod and hook conditions.

Question 28Zpusoby Lovu A Vybaveni

A line repeatedly frays near the same rod ring. Which check addresses a plausible mechanical cause?

  1. Inspect the ring for damage or a rough contact surface. Correct answer.
  2. Assume every new line batch has the same unrelated defect.
  3. Increase the drag until the line stops moving.
  4. Ignore the fraying if no fish has yet been lost.

Explanation

A damaged or rough ring can abrade line repeatedly at that contact. Inspect the actual tackle and address defects instead of treating repeated fraying as harmless or changing tension blindly.

Question 29Zpusoby Lovu A Vybaveni

Why should the quoted breaking strength of an unknotted line not be treated as the guaranteed strength of a complete rig?

  1. Every knot doubles the line’s original strength.
  2. A hook label guarantees the strength of all other components.
  3. The stated line strength applies equally to any damaged section.
  4. Knots, wear and actual loading conditions can reduce the rig’s strength. Correct answer.

Explanation

A complete rig contains knots and components and experiences wear and variable loads. An unknotted line rating does not guarantee that the whole used assembly will withstand the same force.

Question 30Zpusoby Lovu A Vybaveni

A correctly assembled float sinks before any bite when a heavier sinker is added. What is the most direct explanation?

  1. The fish must have swallowed the float itself.
  2. The line has become completely weightless.
  3. The downward load now exceeds the float’s available buoyant support. Correct answer.
  4. The float has become a spinning lure by definition.

Explanation

The float and loading need to be matched. Excess downward load can submerge the float without a bite; this observation alone does not establish a fish or a changed legal method.

Question 31Zpusoby Lovu A Vybaveni

Why are small float shot distributed and adjusted for a particular rig?

  1. To remove every effect of current and wind.
  2. To achieve the intended balance, presentation and bite indication. Correct answer.
  3. To make any hook count legally unlimited.
  4. To guarantee that the largest fish will take the bait.

Explanation

Loading and distribution affect how a float rig sits and presents bait. Adjustment can improve the intended behavior without guaranteeing a catch or removing current, wind and applicable tackle rules.

Question 32Zpusoby Lovu A Vybaveni

What normally provides the visible bite indication in quiver-tip feeder angling?

  1. Deflection or movement of the sensitive rod tip under line tension. Correct answer.
  2. A mandatory surface float on every feeder rig.
  3. A change in the fish’s legal minimum length.
  4. The color of the retained fish in the catch log.

Explanation

The sensitive quiver tip responds to line-tension changes. The angler must distinguish bites from current, wind or other movement rather than assume every deflection proves a fish.

Question 33Zpusoby Lovu A Vybaveni

In conventional fly casting with fly line, what principally carries a very light artificial fly through the cast?

  1. The fly having to weigh more than the entire line.
  2. A permanently attached heavy bottom feeder in every case.
  3. A fish pulling the fly through the air.
  4. The mass of the cast fly line. Correct answer.

Explanation

Conventional fly-line casting uses the line’s mass to deliver a comparatively light imitation. This explains the equipment principle without claiming that every legally defined fly arrangement uses identical tackle.

Question 34Zpusoby Lovu A Vybaveni

What gives a rotating spoon or spinner its characteristic mechanical attraction during retrieval?

  1. The legal permission itself changing the water temperature.
  2. Its label proving it is suitable for all species and conditions.
  3. Movement and vibration associated with its blade in the water. Correct answer.
  4. A guaranteed electrical field that controls every fish.

Explanation

A moving blade can create visual and vibrational signals as the lure travels. That physical action does not guarantee attraction in every species or establish legal suitability for every method.

Question 35Zpusoby Lovu A Vybaveni

Why is casting a long rod near an overhead power line particularly dangerous?

  1. A dry bank makes every overhead-line approach safe.
  2. The rod or line can create a path or close approach for electrical injury. Correct answer.
  3. Fishing line always insulates safely at every voltage.
  4. Only a metal hook can create an electrical hazard.

Explanation

Long rods and lines near electrical conductors present a severe hazard. Material assumptions and a dry bank do not provide permission to approach; choose a safe location away from the line.

Question 36Zpusoby Lovu A Vybaveni

An embedded hook injures a person during angling. What is the appropriate limit of a written tackle lesson?

  1. It does not authorize forceful improvised removal or replace suitable medical advice. Correct answer.
  2. It guarantees that pulling harder is the safest response.
  3. It proves that every deeply embedded hook is superficial.
  4. It makes eye involvement no more urgent than a torn bait packet.

Explanation

A hook injury needs an appropriate response to its actual location and severity. A written tackle explanation is not authorization for forceful extraction, particularly near sensitive structures or the eye.

Question 37Zpusoby Lovu A Vybaveni

Why can a suitable wet landing net help when handling a fish intended for release?

  1. It guarantees survival regardless of air exposure or injury.
  2. It removes the need to identify a protected species.
  3. It makes squeezing the gills an appropriate lifting method.
  4. It can support the fish while reducing abrasive contact with dry ground. Correct answer.

Explanation

A suitable wet net can reduce abrasive handling and support the fish. It does not eliminate other injury risks, identification duties or the need for a careful efficient release process.

Question 38Zpusoby Lovu A Vybaveni

For an ordinary larger freshwater fish briefly handled for release, why is supported horizontal handling preferable to suspension by one jaw?

  1. It proves that measuring is no longer necessary.
  2. It legally converts a retained fish into a different species.
  3. It supports the body and reduces concentrated stress on delicate structures. Correct answer.
  4. It removes every effect of temperature and air exposure.

Explanation

Supporting the body distributes its load more appropriately than suspending a larger fish from one delicate point. Keep handling brief and suitable to the species; support does not eliminate every risk.

Question 39Zpusoby Lovu A Vybaveni

A perch brought rapidly from depth shows an abnormal buoyancy problem. What should an untrained angler avoid doing?

  1. Improvising a needle puncture from an online recipe. Correct answer.
  2. Recognizing that pressure change may be relevant.
  3. Seeking the applicable competent handling guidance.
  4. Reviewing depth and method choices to reduce future risk.

Explanation

Pressure-related injury can occur in susceptible fish brought from depth. An untrained person should not improvise invasive puncture; suitable handling and prevention depend on the actual species and competent guidance.

Question 40Zpusoby Lovu A Vybaveni

Why should a released fish not be carried with fingers pressed through its gill openings?

  1. The gills are a rigid handle designed for suspension.
  2. Pressing the gills guarantees better breathing.
  3. The handling method changes a protected fish into unprotected catch.
  4. The delicate respiratory tissues can be damaged. Correct answer.

Explanation

Gill structures are delicate and essential for respiration. Pressing through the openings can cause damage; use suitable support and minimize unnecessary handling rather than use the gills as a handle.

Question 41Zpusoby Lovu A Vybaveni

Why is suitable moistening often used before tightening a nylon fishing knot, where the line and knot instructions call for it?

  1. To remove the need to inspect the final knot.
  2. To reduce frictional heating and help the knot seat correctly. Correct answer.
  3. To make the line’s diameter permanently zero.
  4. To guarantee that every badly tied knot becomes sound.

Explanation

Moistening can reduce friction during seating under the appropriate line and knot procedure. It does not repair a wrong knot, restore damaged line or remove the need to inspect the result.

Question 42Zpusoby Lovu A Vybaveni

For ordinary Czech trout-district bottom or float angling for non-salmonids, which supplied arrangement matches the general equipment condition?

  1. Any live baitfish may be used if the rod is held.
  2. Three spinning rods may be used because the target is not a trout.
  3. At most two rods with plant-origin bait and the permitted single-hook leaders. Correct answer.
  4. Only one rod is ever allowed for any method on a trout district.

Explanation

The ordinary trout-district bottom or float provision permits up to two rods with the specified plant bait and leader conditions. The one-held-rod rule belongs to other methods, not every trout-district activity.

Question 43Zpusoby Lovu A Vybaveni

Which items does the stated ČRS 2026–27 equipment condition expressly require for ordinary angling?

  1. Only a camera, with no means to measure fish.
  2. A hook disgorger and a fish-length measuring device. Correct answer.
  3. A compulsory live-fish transport tank in every case.
  4. A mandatory boat even when fishing from shore.

Explanation

The stated ČRS condition requires a hook disgorger and a means to measure fish length. A suitable net can help handling, but this condition should not be rewritten as a universal mandatory-net statement.

Question 44Zpusoby Lovu A Vybaveni

What distinguishes ordinary bottom angling from float angling in the stated Czech method definitions?

  1. Bottom angling always means operating an industrial bottom trawl.
  2. Float angling is legally identical to every motorized towing method.
  3. The angler does not actively influence bait movement in bottom angling, while float angling can include that influence. Correct answer.
  4. The methods differ only in the colour of the fishing permission.

Explanation

The definition distinguishes the role of active bait movement in the two methods. This is separate from an industrial net operation, permission color or a blanket equivalence with other towing methods.

Question 45Biologie A Ekologie Ryb

Why should unnecessary air exposure be minimized for an ordinary gill-breathing freshwater fish intended for release?

  1. The fish stops needing oxygen once it has been caught.
  2. Its gills depend on suitable water flow and exposure can impair gas exchange. Correct answer.
  3. Air exposure supplies every fish with more usable oxygen than water.
  4. A wet external skin fully replaces all gill function.

Explanation

Ordinary gill-breathing fish rely on suitable water conditions and effective gill exchange. Unnecessary exposure can impair that process; a damp surface is not a complete substitute for normal aquatic respiration.

Question 46Biologie A Ekologie Ryb

Why can fine silt covering spawning gravel harm species whose eggs depend on clean oxygenated spaces in that gravel?

  1. It turns gravel-spawning eggs into floating marine eggs.
  2. It can reduce water exchange around the eggs. Correct answer.
  3. It guarantees that every egg receives more oxygen.
  4. It makes species-specific spawning habitat irrelevant.

Explanation

Clean interstitial flow can supply oxygen to eggs in gravel. Fine deposited material can obstruct those spaces, so habitat effects depend on the actual species, substrate and water conditions.

Question 47Biologie A Ekologie Ryb

What is a major difference between a physiological oxygen requirement and a legal closed-season date?

  1. One concerns biological function, while the other is a specified legal protection. Correct answer.
  2. They are interchangeable numerical units.
  3. A closed-season date directly measures dissolved oxygen.
  4. Meeting an oxygen requirement cancels the legal closed season.

Explanation

Biological requirements and legal protections address different questions. Suitable oxygen does not remove a closed season, and a calendar date is not a measurement of the actual water’s dissolved oxygen.

Question 48Biologie A Ekologie Ryb

What primarily distinguishes a physoclistous adult swim bladder from a physostomous one?

  1. Complete absence of every buoyancy function.
  2. A requirement that the fish must be a marine shark.
  3. Its replacement of the gills as the main respiratory organ in every species.
  4. Absence of an open pneumatic connection to the gut in the adult. Correct answer.

Explanation

The adult physoclistous arrangement lacks the open pneumatic duct retained in physostomous fish. This affects gas regulation but does not mean the organ has no buoyancy role or replaces ordinary gill respiration.

Question 49Biologie A Ekologie Ryb

Why do aquatic plants not guarantee high dissolved oxygen throughout every night?

  1. Respiration continues in darkness while light-dependent photosynthesis stops. Correct answer.
  2. Plants cease all metabolism whenever the sun sets.
  3. Nighttime oxygen is determined only by the fishing-permit price.
  4. Every plant continuously produces oxygen at an identical daytime rate.

Explanation

Plants respire as well as photosynthesize. Without light, photosynthetic oxygen production stops while respiration and other oxygen demands continue, so nighttime conditions can differ substantially from a sunny afternoon.

Question 50Biologie A Ekologie Ryb

For ordinary ectothermic freshwater fish, why does water temperature matter to activity and oxygen demand?

  1. Temperature changes only the catch-log ink color.
  2. All species respond identically at every temperature.
  3. It affects physiological processes and the environmental conditions around the fish. Correct answer.
  4. The fish always maintains a fixed mammalian body temperature.

Explanation

Ectothermic fish are strongly affected by ambient conditions, including effects on metabolism and oxygen availability. Responses differ by species, acclimation and other conditions rather than follow one universal optimum.