FUDMA department of fisheries and aquaculture technology

02/09/2025

𝐄𝐦𝐩𝐞𝐫𝐨𝐫𝐬

Good to know: protect breeding emperor adults

The most effective community-based management strategy for emperors is likely to involve the protection of breeding adults. Community-managed fish reserves (no-take areas) will not protect reproducing fish that migrate to spawning sites.

Good to know: size limits may not be helpful for emperors

Because emperors start life as females and later change s*x to become males, most of the smaller fish caught are female and the larger ones are male. Catching large, legally-sized fish, therefore, would leave many females but very few males in the sea.

Taking into account the wide variation in sizes of the different species of emperors, these size limits would be of little use for larger species. They would not protect species such as the spangled emperor, for example, which does not reproduce until it reaches a size of about 45 cm. To be effective, size limits should be applied to particular species.
Fishing methods

Fishing methods for emperors include:

baited hooks and lines;

spearfishing, usually during the day;

seine nets and cast nets used in shallow lagoons;

gill netting is the main fishing method and is often used on spawning aggregations.

Many emperors are caught as they gather in large groups to breed (in spawning aggregations). Fishing in this way is destructive as these breeding fish are responsible for producing small fish, many of which will grow and be available to be caught in future years.

Species DSistribution

The Lethrinidae family of fish includes about 20 different species of emperors, which are found almost entirely in the tropical waters of the Indian and Pacific oceans. Features common to all species include thick lips, strong jaws, and cheeks without scales.

Habitat and Feeding

Most species of emperors live on coral reefs or areas associated with them, including sandy areas and seagrass beds in lagoons. Some species live on rocky reefs down to depths of more than 200 m. Th

01/09/2025

The fish is said to be 3 months old from Juveniles!
Let me know your thoughts and as a real aquaculturist, identify the major challenge the owner of the fish encountered during these 3 months of raising the fish.

LET ME KNOW THE REAL FARMERS HERE!

Are you a beginner or a potential aquaculturist? JOIN OUR PRACTICAL ONLINE CLASS ON CATFISH FARMING AND MANAGEMENT Using the link in the comment section .

YOU CAN ALSO ENJOY FREE SMART LIVESTOCK CALCULATOR NOW ON LIVESTOCADEMY'S WEBSITE BY CLICKING THE LINK IN THE COMMENT SECTION

Disclaimer: This picture is not mine and photo credit to the rightful owner Caeser M

01/09/2025

𝐖𝐡𝐚𝐭 𝐚𝐫𝐞 𝐬𝐢𝐳𝐞 𝐥𝐢𝐦𝐢𝐭𝐬 𝐚𝐧𝐝 𝐬𝐩𝐞𝐜𝐢𝐞𝐬 𝐛𝐚𝐧𝐬?

Size limits are a fisheries management tool used to delimit the sizes at which fish or invertebrates can be caught.

Species bans are a fisheries management tool that prohibits the catching and retaining of selected species.

What is the purpose of size limits and species bans?

The reason for the application of minimum size limits is to allow individual species to grow to a size at which they can spawn at least once before capture. Banning the catching of selected species is aimed at protecting those that are under threat or endangered, usually from excessive fishing.

When and where should we use size limits and bans?

Size limits have been applied by fisheries departments or agencies in most Pacific Island countries and territories to a wide range of species of inshore pelagic fish, reef fish, sea cucumber, clam, trochus, green snail, crab and lobster. These size limits and bans should be publicised and respected by communities as well as commercial fishers.

Different countries may have different ways of measuring marine resources. Standard length measurements are shown in the accompanying figure for various groups of marine species. From left, clockwise: carapace length (CL) of a lobster; shell length (L) of a clam; and either total length (TL) or caudal fork length (CFL) of a fish.

For some species, an upper size limit has been applied in addition to a minimum size limit. This is usually justified on the grounds that larger individuals produce a disproportionately greater number of eggs than smaller individuals.

The figure below shows a younger female fish. When a fish doubles in size - depth, width and length, its volume increases eight times; and as egg carrying capacity is related to volume, the number of eggs also potentially increases by eight.

Upper size limits may also be applied in cases where larger individuals are less marketable than smaller individuals. Large trochus she

31/08/2025

𝐏𝐮𝐟𝐟𝐞𝐫𝐟𝐢𝐬𝐡𝐞𝐬 𝐚𝐧𝐝 𝐓𝐡𝐞𝐢𝐫 𝐑𝐞𝐥𝐚𝐭𝐢𝐯𝐞𝐬

Pufferfishes are related to some surprising relatives, like the massive sunfish (𝑴𝒐𝒍𝒂 𝒎𝒐𝒍𝒂). The order Tetraodontiformes (which includes the pufferfishes and the sunfishes) contains 447 species in ten families.

Source:

https://ocean.si.edu/ocean-life/fish/pufferfishes-and-their-relatives

30/07/2025

30/07/2025

Fisheries vs. Aquaculture

Fisheries encompass the harvesting of wild aquatic organisms—fish, crustaceans, mollusks—either from natural habitats (rivers, lakes, oceans) or from stocked water bodies. Management focuses on sustainable catch limits, habitat protection and monitoring wild populations.

Aquaculture is the controlled cultivation of aquatic species in managed systems. It involves breeding, rearing and harvesting fish, shellfish or aquatic plants in ponds, tanks, cages or raceways. The goal is to optimize production through feed management, water quality control and selective breeding.

Types of Aquaculture Ponds

1. Earthen Ponds

Dug directly into soil.

Low construction cost; rely on natural fertility.

Common in extensive or semi‐intensive systems.

2. Concrete (or Cement) Ponds

Paved walls and bottom.

Easier to clean and disinfect; precise depth control.

Used for species requiring high biosecurity or intensive culture.

3. Plastic‑Lined Ponds

Plastic or geomembrane liner over an earthen floor.

Prevents seepage, reduces soil contamination.

Suited for sites with porous soils.

4. Nursery Ponds

Shallow, small ponds for fry (young fish) rearing.

High stocking density; frequent water changes.

5. Rearing (Grow‑Out) Ponds

Larger, deeper ponds for growing juveniles to market size.

May be managed as extensive (low input), semi‑intensive or intensive systems.

6. Broodstock Ponds

Designed to hold mature fish for spawning.

Often include spawning substrates or controlled flow.

7. Flow‑Through Ponds

Continuous supply of fresh water enters and exits.

Maintains high water quality but requires abundant water source.

8. Recirculating Systems (RAS) Ponds

Water is continuously filtered and reused.

Allows intensive culture with minimal water use; higher capital cost.

Each pond type is chosen based on local soil and water conditions, target species, scale of production and available investment.

11/02/2024

Guides for Exporting live fish in Nigeria 🛳️✈️🇳🇬

The Inland Fisheries Decree No 108 of 1992, section 8, prohibits the Importation and Exportation of live fish or any other aquatic animal except for research and museum collection purposes.

However, the Federal Department of Fisheries (FDF) gives permit to would be importers and exporters after meeting the following requirements;

09/04/2023

Fisheries for self reliance

17/06/2021

During ours forestry practical, fisheries 200 level.

13/04/2020

Ranar Litinin Sheikh Ja'afar Mahmud Adam ya cika shekara 13 da rasuwa.
An harbe fitaccen malamin addinin Musuluncin ne yayin da yake jan sallar Asuba a wani masallaci a Kano, a ranar Juma'a 13 ga watan Afrilun shekarar 2007.