2025 NECO FISHERIES: NECO Fisheries (Fishery) 2026 Legit Ans. (2269)

(2ai)

Fish preservation is the process of treating, storing, or handling fish in such a way that it prevents spoilage, maintains freshness, and extends shelf life for future use or sale.

(2aii)

(PICK ANY TWO)

(i) Smoking: This involves exposing fish to heat and smoke from burning wood or charcoal. It removes moisture from the fish, kills bacteria, and gives it a distinct flavor, helping to preserve it for a longer time.

(ii) Freezing: Fish is stored at very low temperatures (usually below 0°C) to slow down microbial and enzymatic activities. This method helps to keep fish fresh and safe for consumption over time.

(iii) Drying: This involves removing water from fish either by sun-drying or using artificial heat. Drying reduces moisture content and prevents the growth of spoilage organisms.

(iv) Salting: Salt is applied to the fish, drawing out water through osmosis. The high salt concentration prevents the growth of bacteria and preserves the fish for a longer period.

(v) Canning: Fish is first cooked and then sealed in airtight containers like tins or cans. The process involves heating to destroy all microbes, making the fish safe and durable for long-term storage.

(vi) Pickling: Fish is preserved in vinegar, brine (saltwater), or other acidic solutions. The acid environment inhibits bacterial growth and enhances the flavor while keeping the fish from spoiling.

(2aiii)

(PICK 'copied from e x a m p l a z a s . c o m free' ANY TWO)

(i) Smoking uses heat, while freezing uses cold temperatures.

(ii) Smoking gives fish a distinct flavor, while freezing retains the natural taste.

(iii) Smoked fish is ready to eat, but frozen fish usually needs cooking.

(iv) Smoking can be done without electricity, while freezing requires constant power.

(v) Smoking reduces weight due to moisture loss, while freezing retains weight.

(vi) Smoking causes texture changes, while freezing preserves the original texture.

(2bi)

Area = Length × Breadth

Length = Area / Breadth = 3,500 / 50 = 70 meters

(2bii)

(PICK ANY ONE)

(i) Hatchery

(ii) Spawning pond

(iii) Incubation tanks

(iv) Nursery pond

(v) Broodstock tank

(2biii)

(i) Close season: Close season refers to a period when fishing activities are temporarily banned or restricted to allow fish to breed, spawn, and grow without human interference. This helps to maintain fish populations and promote sustainable fishing.

(ii) Avoidance of breeding ground: This means intentionally staying away from areas where fish reproduce, such as shallow waters, riverbanks, or wetlands, during the breeding season. The goal is to protect eggs, fry, and young fish from being caught or destroyed, which helps to increase fish stock and protect aquatic biodiversity.

(3ai)

Draw the diagram

(3aii)

(PICK ANY FOUR)

(i) Provides employment opportunities

(ii) Increases availability of protein-rich food

(iii) Reduces pressure on natural water bodies

(iv) Generates income for fish farmers

(v) Encourages agricultural development

(vi) Promotes export and foreign exchange earnings

(vii) Enhances food security in the country

(viii) Provides raw materials for agro-industries

(3aiii)

(PICK ANY TWO)

(i) Both require human management

(ii) Both use artificial or supplementary feeding

(iii) Both involve pond monitoring

(iv) Both need disease and predator control

(v) Both allow for moderate fish stocking density

(vi) Both combine fish with other farming systems

(vii) Both depend on proper water quality management

(viii) Both aim at increasing productivity and profit

(3bi)

Fish feed refers to nutritious food substances specially prepared or selected to be fed to fish in order to promote healthy growth, development, and reproduction in aquaculture systems.

(3bii)

(i) Mash

(ii) Pellets

(iii) Crumbles

(iv) Flakes

(3biii)

(PICK ANY TWO)

(i) Higher fish production per unit area

(ii) Faster growth rate of fish

(iii) Efficient use of water and space

(iv) Better control over fish 'copied from e x a m p l a z a s . c o m free' environment

(v) Allows for year-round fish farming

(vi) Easy monitoring and disease management

(3biv)

(PICK ANY TWO)

(i) High cost of feeding and equipment

(ii) Requires constant monitoring and skilled labor

(iii) Greater risk of disease outbreak

(iv) High energy consumption (e.g., for aerators)

(v) Stress on fish due to high stocking density

(vi) Waste buildup leading to water pollution if not managed

(4ai)

(PICK ANY FOUR)

(i) Dragonfly nymphs feed on fish eggs and larvae.

(ii) Reduced survival rate of fry due to predation.

(iii) Increased stress level among juvenile fish.

(iv) Decreased fish population in the hatchery.

(v) Disruption of normal fish feeding behaviour.

(vi) Economic losses due to poor yield.

(vii) Injury to young fish, leading to infections.

(viii) Increased cost of farm management (e.g., need for protective netting).

(4aii)

Shellfish culture refers to the farming or cultivation of shell-bearing aquatic animals like shrimps, oysters, mussels, and crabs in a controlled water environment such as ponds, tanks, or cages for commercial or subsistence purposes.

(4bi)

(PICK ANY FOUR)

(i) Ichthyophthiriasis (Ich)

(ii) Trichodiniasis

(iii) Gyrodactylosis

(iv) Lernaeasis (anchor worm)

(v) Fish lice infestation (Argulus)

(vi) Costiasis

(vii) Myxosporidiosis

(viii) Dactylogyrosis

(4bii)

=Ichthyophthiriasis (Ich)=

(PICK ANY TWO)

(i) White spots on the skin and fins

(ii) Flashing (rubbing body against surfaces)

(iii) Loss of appetite

(iv) Rapid gill movement

(v) Hanging at water surface

(vi) Sluggish or erratic swimming

=Trichodiniasis=

(PICK ANY TWO)

(i) Excess mucus on body

(ii) Dull or faded skin 'copied from e x a m p l a z a s . c o m free' coloration

(iii) Frayed or clamped fins

(iv) Gasping for air at surface

(v) Poor growth and weight loss

(vi) Gathering at the pond inlet or edges

=Gyrodactylosis=

(PICK ANY TWO)

(i) Clamped fins

(ii) Skin redness or hemorrhages

(iii) Lethargy and hiding behaviour

(iv) Peeling or damaged skin

(v) Inflammation at gills

(vi) Sudden death in large numbers in advanced stages

(4biii)

(PICK ANY TWO)

(i) Faster and uniform growth

(ii) Prevents unwanted reproduction

(iii) Easier size grading and harvesting

(iv) Reduces competition between mature and young fish

(v) Increases feed efficiency

(vi) Minimizes aggression (if same gender)

(vii) Higher survival rate

(viii) Better yield prediction and planning

(4biv)

(PICK ANY TWO)

(i) Uneven growth due to species competition

(ii) Difficulty in feeding management

(iii) Higher disease spread risk

(iv) Difficult to monitor individual species

(v) Unequal market value of different species

(vi) High mortality rate if species are incompatible

(vii) Complicated water quality control

(viii) Possible predation of smaller species by larger ones

(5ai)

Fish farming is the practice of breeding and raising fish in controlled environments such as ponds, tanks, or cages for food production or commercial purposes.

(5aii)

(i) Fast growth rate

(ii) Resistance to disease

(iii) Market demand/value

(iv) Ability to adapt to local environmental conditions

(5aiii)

=Similarities=

(PICK ANY TWO)

(i) Both are freshwater fish.

(ii) Both are native to Africa.

(iii) Both are commonly cultured in Nigeria and other tropical countries.

(iv) Both grow rapidly under good management.

(v) Both can be raised in ponds, tanks, and cages.

(vi) Both have high economic value and market demand.

(vii) Both reproduce in captivity.

(viii) Both species tolerate a wide range of water temperatures.

=Differences=

(PICK ANY TWO)

(i) Oreochromis niloticus is herbivorous, while Clarias gariepinus is omnivorous/carnivorous.

(ii) Oreochromis has scales, while Clarias is scaleless.

(iii) Oreochromis is a day feeder, while Clarias feeds mostly at night.

(iv) Oreochromis uses mouthbrooding for reproduction; Clarias spawns and guards eggs in nests.

(v) Clarias has barbels (whisker-like feelers); Oreochromis does not.

(vi) Clarias can survive in low oxygen levels by gulping air; Oreochromis cannot.

(vii) Oreochromis thrives better in clear water, while Clarias can 'copied from e x a m p l a z a s . c o m free' tolerate muddy or poor water quality.

(viii) Clarias has a longer body and flat head, while Oreochromis has a more compact, rounder body.

(5bi)

Aquatic weed is any unwanted or harmful plant that grows in a water body and competes with fish for oxygen, light, and nutrients, thereby affecting fish growth and water quality.

(5bii)

(PICK ANY TWO)

(i) Reduces oxygen level in the water

(ii) Blocks sunlight penetration

(iii) Harbours predators and parasites

(iv) Makes harvesting difficult

(v) Competes with fish for nutrients

(vi) Causes water pollution when decayed

(5biii)

(i) Catadromous: A catadromous fish is a fish that spends most of its life in freshwater, but migrates to the sea (saltwater) to spawn (lay eggs). After spawning, the young may return to freshwater and continue the cycle.

(ii) Gravid fish: A gravid fish is a female fish that is full of mature eggs and is physically ready to lay them. The fish usually shows signs such as a swollen abdomen, slowed movement, and may isolate itself in preparation for spawning.