Visible Fish and Shadows - Dynamic Fish Behavior

For demo purpose, the setting below will make water source appear way more fish that default setting, feel free to customize your own fish experience

Visible Fish & Shadows


Customizable Underwater Fish Simulation


Brings water to life with realistic swimming fish! Choose between atmospheric dark shadows or vibrant colored fish with fully customizable behavior, lifespans, and population density.

Overview


Fish & Shadows adds animated fish to all water bodies in Stardew Valley. Fish swim with realistic physics, avoid crowding, take breaks, and naturally fade away after their lifespan ends. The mod is highly customizable through Generic Mod Config Menu.


Key Features:

• Toggle between shadow silhouettes or full-color visible fish
• Realistic stop-and-go swimming physics with individual fish personalities
• Natural lifespan system - fish fade away after 2-5 minutes and new fish spawn to replace them
• Individual size variation - each fish has a unique size for natural diversity
• Optimized spawning for fish ponds and small water bodies
• Fish avoid crowding and steer away from each other
• Optional nighttime hiding - fish disappear after sunset

Configuration -  The mod is highly customizable, if you do not like the default, here is a config guide to make your own experience: 


All settings are fully configurable through Generic Mod Config Menu.


Visuals

• Shadow Opacity - How dark the fish appear (0.1 = faint, 1.0 = solid)
• Show Visible Fish - Toggle between dark shadows or full-color fish
• Enable Fade Effects - Fish fade in smoothly when spawning and fade out when despawning
• Min/Max Fish Size - Control the size range for individual fish. Set both to the same value for uniform sizes, or create variety with different min/max values
• Modded Fish Rotation - Rotation offset for modded fish sprites (vanilla fish are handled automatically)

Behavior & Physics

• Enable Physics - Realistic stop-and-go swimming behavior. When disabled, fish swim constantly in circles
• Avoid Crowding - Fish gently steer away from each other to prevent clumping
• Constant Swim Chance - Percentage of fish that never stop to rest (0.0 - 1.0)
• Global Swim Speed - Multiplier for swimming speed. Lower = slower and more relaxed
• Min/Max Idle Time - How long fish rest before moving again
• Burst Chance - Probability that fish will sprint quickly instead of swimming slowly
• Min/Max Lifespan - How long each fish lives before fading away and respawning elsewhere (in seconds)

Population

• Min/Max Fish Count - The number of fish that spawn when entering a location
• Spawn Density - Probability of fish spawning per tile check
• Density Safety Cap - Multiplier for the overcrowding limit. Increase for more fish in small areas
• Initial Spawn Percentage - Percentage of fish that appear instantly when entering a map

Locations & Time

• Farm Only - Restrict fish to only appear on the farm
• Excluded Locations - Comma-separated list of location names to ignore
• Hide at Night - Fish disappear after sunset
• Hours After Sunset - How many hours after sunset before fish disappear

Special Features


Natural Lifespan System
Fish don't live forever! Each fish is assigned a random lifespan when it spawns. When the lifespan ends, the fish fades away and a new fish spawns elsewhere. This prevents overcrowding and keeps the population feeling fresh and dynamic.


Location-Specific Adjustments
Some modded locations with excessive water automatically spawn fewer fish to prevent overcrowding. Currently includes Custom_ShearwaterBridge with a 50% reduction.

Installation


Requirements:

• SMAPI 4.0.0 or higher
• Generic Mod Config Menu (optional but recommended)

Steps:

• Install SMAPI
• Download this mod
• Unzip the mod folder into your Stardew Valley/Mods folder
• Run the game using SMAPI
• Optional: Install Generic Mod Config Menu to configure settings in-game

Compatibility

• Works with all vanilla and modded locations that have water
• Compatible with fish pond mods
• Works in multiplayer (each player sees their own fish)
• No conflicts with other visual mods
• Safe to add or remove from existing saves

Performance


The mod is optimized for performance:

• Fish outside the viewport are culled from rendering
• Lower fish counts (100-150) recommended for lower-end systems
• Higher counts (300+) will use more resources but create more lifelike waters
• Adjust population settings if you experience lag

FAQ


Q: I can't see any fish!
A: Make sure you're in a location with water. Check your config settings - ensure Min/Max Fish Count is above 0 and you haven't excluded the location.


Q: Fish ponds have too few fish
A: The mod automatically detects fish ponds and spawns more fish there (minimum 15). Try increasing the Density Safety Cap multiplier.


Q: I want all fish to be the same size
A: Set Min Fish Size and Max Fish Size to the same value (e.g., both at 1.0).


Q: Fish disappear too quickly
A: Increase the Max Lifespan setting. Default is 300 seconds (5 minutes), you can set it up to 600 seconds (10 minutes).


Q: Too many fish in a specific location
A: Add the location name to the Excluded Locations list, or report it and I can add a location-specific cap reduction.