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Topsmelt ID card
Activity
Spearfishing
Rarity
Common
Primary biome
Bay
Secondary biomes
Protection Status:
Not Protected
Hunting is allowed, with regulations.
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Spearfishing Stats

Weapon of choice
No spearfishing account exists for the species; a dip net or a baited hoop net is the method California specifically permits
Abundance
5 / 5

Abundant at nearly every California pier and in every southern California bay and kelp bed; 84 percent of the state's topsmelt catch comes from southern California.

Find difficulty
1 / 5
Shot difficulty
3 / 5

Taxonomy

Phylum
Chordata
Class
Actinopterygii
Order
Atheriniformes
Family
Atherinopsidae
Genus / Species
Atherinops affinis
Family, common name
Neotropical silversides

Rarity

Average rarity
Common
Conservation status
Least Concern (2008)

Topsmelt are everywhere a California diver goes, and they are usually the first fish in the water and the last one out. They hold in the surface layer of bays, sloughs and kelp beds along the entire coast, they are caught at nearly every pier in the state, and they have no bag limit because there has never been a reason to set one. The IUCN lists the species as Least Concern, assessed in 2008. Within California the distribution leans south. Topsmelt make up a smaller share of the silverside catch than jacksmelt, roughly 15 to 18 percent depending on the survey period, but 84 percent of the topsmelt caught in the state come from southern California, and that figure has climbed since the 1980s. The Department of Fish and Wildlife has never estimated the stock and reports no sign of overharvest. What the agency does flag is where the fish breeds. Topsmelt glue their eggs to eelgrass and low-growing algae inside bays and estuaries, which ties the species to exactly the habitat most exposed to pollution, dredging and shoreline development.

Regulations

CDFW rules verified 2026-09-06

Size limit
None
Bag limit
None. Topsmelt has no bag limit at all under the general finfish rule
Seasonality
Open year-round
Geographic constraints
Statewide. Topsmelt is 1 of the few species California allows to be taken with a dip net or a baited hoop net, and with a Hawaiian throw net north of Point Conception

Seasonality

Nearshore season
Year-round in the surface water of bays, sloughs and kelp beds
Offshore season & where
Not an offshore species; recorded to about 85 feet
Breeding season
Mid-May through early July, in shallow water
Breeding-season aggression
None documented; spawning females are accompanied by several males
Best season to target & why
Year-round, with the largest fish at the northern end of the range

Edibility

Meat type
Soft and mild, and very small
Difficulty to fillet
5 / 5
Fillet quality
2 / 5

A fish that rarely passes 10 inches gives essentially no fillet, which is why it is cooked whole.

Taste
Mild
Eating quality
2 / 5 · Fair
Traditional preparations
Cooked whole; also used as live and cut bait

Location

Range
The Gulf of California north to 4 miles west of Sooke Harbour, Vancouver Island, British Columbia, including Guadalupe Island, Baja California
Habitat
Surface water of bays, sloughs, estuaries and kelp beds, usually in the top 15 feet, over mud and rock alike
Biomes frequented
Bay biomeKelp Forest biomeSeagrass Bed biome

Topsmelt range from the Gulf of California north to a point about 4 miles west of Sooke Harbour on Vancouver Island, British Columbia, and the range includes Guadalupe Island off Baja California. That is a long coastline for a fish under 15 inches. They live in the surface water of bays, sloughs, estuaries and kelp beds, over mud and over rock, and they concentrate in the top 15 feet. The common name is a description of the habit. Depth records reach about 85 feet, but a topsmelt spends its life near the ceiling.

Size varies with latitude in a way worth knowing. The largest fish are found at the northern end of the range, and the biggest topsmelt ever recorded measured 14.5 inches, against 17.5 inches for the largest jacksmelt. Most of what a southern California diver sees is under 10 inches. Growth is quick and then stops mattering. A topsmelt puts on 2.5 to 4 inches in its first year and another 2 inches in its second, by which time most are mature, and the oldest fish measured have been 7 to 8 years.

Spawning happens from the middle of May through early July, in shallow water, with a female accompanied by several males. The eggs go onto eelgrass blades and low algae, held there and to each other by sticky filaments. After hatching, the young move into the surface canopy of the kelp forest, where topsmelt larvae and juveniles occur in enormous numbers alongside young jacksmelt. The bright clouds of small silver fish at the top of a kelp bed in early summer are mostly these 2 species.

Spearfishing Brief

Topsmelt are not a spearfishing target and no account of hunting them exists. What follows is reasoned from documented behavior and from what California law actually permits, and the difference is stated rather than papered over.

Finding them rates a 1, the floor of the scale. Schools sit in the surface water of every bay, slough and kelp bed on the coast and in the top 15 feet off nearly every pier. A diver does not look for topsmelt. The shot rates a 3, and the reason is size more than caution. A topsmelt is usually under 10 inches and never much over 14, which is a narrow target moving fast inside a school that shifts as a unit, over open water with no structure to hold a fish in place. Overall difficulty is 3.

The method the state actually points at is a net. Topsmelt is 1 of a short list of species California allows to be taken with a dip net of any size or a baited hoop net up to 36 inches across, and north of Point Conception, Santa Barbara, with a Hawaiian style throw net. Its larger relative the jacksmelt is not on that list and has to be taken on a line or with a spear. Anglers who want topsmelt in quantity chum with bread crumbs and scoop the feeding mass, a technique the Department of Fish and Wildlife describes for the juveniles of both silversides. Where hook and line is used, southern California anglers fish snag lines and northern anglers fish small baited pieces on a multi-hook leader.

On the table, topsmelt are food but barely worth cutting. The flesh is mild and soft, the same description that follows jacksmelt around, and the fish is small enough that filleting makes no sense. Anything eaten is cooked whole. The other issue is the same one, which is worms. Parasites are common enough in the flesh that they put many California anglers off the species, though they are harmless once the fish is cooked. Most topsmelt taken in California end up as bait rather than dinner, live or cut, which is a fair reflection of where the species sits.

Deep Dive

Topsmelt are named for a habit and misnamed for a family. The first half is accurate: they swim at the top. The second half is not, because a topsmelt is not a smelt at all. True smelt are closer relatives of trout, carry a small fleshy adipose fin between the dorsal fin and the tail, have a single dorsal fin, and have pectoral fins set low on the body. Topsmelt have no adipose fin, 2 dorsal fins, and pectoral fins set high. Their nearest relatives are the mullet and the barracuda. California ocean water holds 3 silversides, and the other 2 are the jacksmelt and the California grunion.

Telling a topsmelt from a jacksmelt takes 2 characters. On a topsmelt, the anal fin, the unpaired fin on the underside behind the vent, starts directly below the back end of the first dorsal fin. On a jacksmelt it starts between the 2 dorsal fins. The teeth differ as well: topsmelt teeth are forked and sit in a single row along the jaw, while jacksmelt teeth are unforked and set in several bands. The color is the same on both, green over blue-green above, silver on the sides, with the blue stripe down the middle that gives the whole family its name.

The species has a history of being split apart and put back together. Topsmelt from different bays and different habitats look different enough that biologists once treated them as separate subspecies. That has not held. Topsmelt has been recognized as a single species for more than 25 years, and a 2004 study by Kathleen O'Reilly and Michael Horn measured the shape variation directly and found it to be variation within a single species rather than evidence of several.

What the fish does with its gut is the reason that variation exists, and it is the most interesting thing about the animal. Silversides have no stomach. Food goes from the throat straight into the intestine with no acid chamber between them. In 2006 a team led by Horn published a study in Marine Biology comparing the digestive systems of topsmelt, jacksmelt and grunion, and found that the 3 species had taken that same stomachless plumbing in 3 directions. Grunion eat only animals. Jacksmelt are mostly carnivores with some plant material. Topsmelt do both, and which one depends on where the individual fish lives. Topsmelt in estuaries eat mostly algae. Topsmelt in kelp forests eat mostly animals. The study measured the difference inside the fish, not just in the stomach contents: estuary topsmelt had the longest guts, the largest surface area in the intestinal lining, and the highest activity of the enzymes that break down starch. The same species, a few miles apart, is built differently to match what it is eating.

The other extreme trait is salt. Topsmelt handle a range of salinity that almost nothing else on this coast can match, from fresh water at 1 end to water far saltier than the sea at the other. Ordinary seawater runs about 34 parts per thousand. When the State Water Resources Control Board needed to know how California test species would react to the brine that desalination plants discharge, a University of California, Davis team ran the numbers, and larval topsmelt survived to about 60 parts per thousand before half the test animals died. That put topsmelt among the most salt-tolerant of the 9 organisms tested, alongside mysid shrimp, which are small shrimp-like crustaceans, and giant kelp.

That tolerance is also why the fish shows up in laboratories. Topsmelt is 1 of the 9 standard test species written into the California Ocean Plan, which means the state uses it to decide whether a discharge is toxic to coastal water. Larval topsmelt survival and growth are the measurement. A fish that will keep living across a wide range of temperature and salinity makes a clean test animal, because a result can be attributed to the contaminant rather than to the conditions of the test.

For everything else in the water, topsmelt are food. The Department of Fish and Wildlife lists them as an important forage species for marine birds, fish and mammals, and other accounts name sea lions and seals specifically. A school of topsmelt in the kelp canopy is not the interesting animal on a dive. It is the reason the interesting animal is there.

Where to Find Them

Beaches whose habitats match this species

Matched by habitat: a beach is listed when its biome tags overlap this species' biomes.

Topsmelt — Ichthyopedia | Nautical Nick