Spotfin surfperch
A small surfperch with distinctive dark blotches on its fins.
The spotfin surfperch (*Hypocritichthys analis*) is a ray-finned fish belonging to the surfperch family Embiotocidae. In Mexico, it is sometimes called *mojarra aletimanchada*. Originally classified under the genus *Hyperprosopon* as *Hyperprosopon anale*, it was reassigned to its own monotypic genus in 2018. It remains in the subfamily Amphistichinae, alongside *Hyperprosopon* and *Amphisticus*.
This species is relatively small, reaching a total length of 20 cm (7.9 in), though individuals around 14 cm (5.5 in) are more typical. Its body is more elongated than that of related *Hyperprosopon* species. It has a small, slightly upturned mouth. The body is silvery, with a dusky, sometimes purplish back. The dorsal fin contains 8 spines and 13 to 15 rays, while the anal fin has 3 spines and 21 to 22 soft rays. The fish is named for the dark blotches at the front of the dorsal fin and the middle of the anal fin.
The spotfin surfperch occurs along the western coast of North America from Oregon to Baja California, but is most common around central California. It often shares sandy, wave-broken zones with other surfperches in the subfamily Amphistichinae. While it can be found as deep as 101 m (331 ft), it is more common in shallow nearshore areas.
This species is viviparous: juveniles are fertilized and develop inside the mother, and are born fully formed and able to swim between June and August. The number of young depends on the female’s size and age. Males may grow more slowly than females. Their diet consists mainly of small crustaceans and zooplankton.
Quick Facts
- Taxon
- Hypocritichthys analis
Facts from the source article.
Lore & Background
The spotfin surfperch is a relatively small species, reaching a total length of 20 cm, though more common around 14 cm. Its body is relatively elongated compared to species in the related Hyperprosopon, with a small, slightly upturned mouth. The body is silvery, with a more dusky back that can be purpleish. The dorsal fin has 8 spines and 13 to 15 rays, while the anal fin has three spines and 21-22 soft rays. Notably, it is identified by the distinctive dark blotches at the front of the dorsal and middle of the anal fin, which is the namesake of the species.
It occurs along the western coast of North America from Oregon to Baja California, but is most common around central California. Spotfin surfperch are often found with other species of surfperch in the subfamily Amphistichinae in sandy zones with breaking waves. They can be found as deep as 101 m, but are more common in shallow nearshore areas.
Spotfin surfperch are viviparous, with juveniles fertilized and developing inside the mother. The young are birthed between June and August fully formed and able to swim. The amount of young birthed depends on the size and age of the female. Males may grow slower than females. They feed primarily on small crustaceans and zooplankton.
Reader's Guide
The spotfin surfperch is notable for its distinctive dark blotches on the dorsal and anal fins, which give the species its common name. Its placement in a monotypic genus since 2018 reflects taxonomic refinement within the surfperch family. Ecologically, it shares sandy, wave-broken zones with other Amphistichinae species and is viviparous, with young born fully formed between June and August. Its diet of small crustaceans and zooplankton places it as a nearshore predator. The species is most common around central California, though its range extends from Oregon to Baja California. Its relatively small size and elongated body distinguish it from related surfperches.
Did You Know?
- The spotfin surfperch was placed in its own monotypic genus in 2018, previously being classified in Hyperprosopon.
- It is identified by distinctive dark blotches at the front of the dorsal fin and middle of the anal fin.
- Females give birth to fully formed, swimming young between June and August.
Frequently Asked Questions
What is the spotfin surfperch?
The spotfin surfperch (Hypocritichthys analis) is a small ray-finned fish in the surfperch family Embiotocidae, native to Mexican waters where it goes by the local name mojarra aletimanchada. It belongs to the subfamily Amphistichinae, sharing that group with the genera Hyperprosopon and Amphisticus.
How big does a spotfin surfperch get?
Most individuals you'll encounter measure around 14 cm (5.5 in) in total length, though the species tops out at roughly 20 cm (7.9 in). It is on the smaller end of the surfperch family.
What makes the spotfin surfperch look different from other surfperch?
Its most eye-catching feature is the series of dark blotches scattered across its fins, which sets it apart from the more uniformly colored Hyperprosopon relatives. Its body is also noticeably more elongated than those close cousins.
Why was the spotfin surfperch given its own genus?
It was originally described as Hyperprosopon anale, but in 2018 taxonomists determined it warranted separation and placed it in the monotypic genus Hypocritichthys. The reassignment better reflects its distinct body proportions and fin patterning.
What does the spotfin surfperch's fin formula look like?
Its dorsal fin is built from eight spines followed by 13 to 15 soft rays, while the anal fin carries three spines and 21 to 22 soft rays. The dark spotting on these fins is the trait that gives the species its common name.
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