Overview

Fishes are gill-bearing aquatic craniate animals that lack limbs with digits. They form a paraphyletic group, meaning the group includes a common ancestor but not all of its descendants (tetrapods, for example, are excluded). Most fishes are ectothermic, with body temperatures that vary with ambient water temperature. The group encompasses hagfish, lampreys, cartilaginous fishes (sharks, rays, skates), and bony fishes, the latter comprising over 95 percent of living fish species [1][2].

Origin and history

Fishes are the oldest vertebrate group, with fossil records dating to the Cambrian period, roughly 530 million years ago. The earliest known fish-like vertebrates were jawless ostracoderms. Jawed fishes (gnathostomes) appeared in the Silurian, and by the Devonian period (the “Age of Fishes”) they had diversified into major lineages including placoderms, acanthodians, and early bony fishes [1]. Modern fish groups — chondrichthyans (cartilaginous fishes) and actinopterygians (ray-finned fishes) — emerged by the late Paleozoic. The classification of fishes is contested among ichthyologists; the term “fish” has no standing in cladistic taxonomy because it excludes tetrapods, which are descended from lobe-finned fishes [2].

Varieties and aliases

  • Jawless fishes (Agnatha): hagfish and lampreys
  • Cartilaginous fishes (Chondrichthyes): sharks, rays, skates, chimaeras
  • Bony fishes (Osteichthyes): ray-finned fishes (Actinopterygii) and lobe-finned fishes (Sarcopterygii)
  • The term “fish” is also used in compound names for aquatic animals that are not true fishes, such as jellyfish, starfish, and cuttlefish, though these are not classified as fishes

Culinary uses

Fishes are a primary protein source across virtually all cuisines. Preparation methods vary by species, fat content, and cultural tradition: raw (sashimi, ceviche, crudo), cured (gravlax, pickled herring), smoked (hot-smoked mackerel, cold-smoked salmon), dried (bacalao, stockfish), fermented (surströmming, fish sauce), and cooked by grilling, frying, steaming, poaching, or baking. In Mexican cuisine, fishes such as huachinango (red snapper) are used in Veracruz-style preparations, and dried fish (pescado seco) appears in Oaxacan and Yucatecan dishes. In Japanese cuisine, species like maguro (tuna), sake (salmon), and saba (mackerel) are central to sushi and sashimi. In Korean cuisine, grilled mackerel (godeungeo-gui) and fish-based stews (maeuntang) are common. In Filipino cuisine, fish is often fried whole (daing na bangus) or cooked in vinegar (paksiw). In Peruvian cuisine, fish is the base of ceviche, typically using corvina or flounder.

Cross-cuisine context

Fishes are a universal ingredient with no single analogue across cuisines. In the Mexican culinary tradition, freshwater fishes such as mojarra (tilapia) and charales (small silversides) are used in soups, tacos, and fritters, while marine species like huachinango and sierra (mackerel) appear in coastal regions. In the LA-relevant cuisines of the corpus, fish occupies a central role in Japanese (sashimi, grilled fish), Korean (grilled fish, fish stews), Vietnamese (cá kho tộ, fish sauce), Filipino (sinigang na isda, paksiw), and Peruvian (ceviche) cooking. In Salvadoran and Guatemalan cuisines, fish is less prominent inland but appears in coastal preparations such as sopa de pescado and fried fish with curtido. In Armenian and Persian cuisines, fish is traditionally eaten on specific occasions (e.g., Persian sabzi polo ba mahi for Nowruz). In Arabic cuisines, fish is grilled (samak mashwi) or fried and served with rice and tahini sauce. In Russian cuisine, fish is preserved (salted herring, smoked fish) and used in salads (seledka pod shuboy) and soups (ukha). In Cambodian cuisine, fish is central to prahok (fermented fish paste) and amok trei (steamed fish curry). No direct analogue exists because fish is not a single ingredient but a category of thousands of species with distinct culinary roles.

Notes for cooks

  • Freshness is the primary signal for quality: whole fish should have clear eyes, bright red gills, firm flesh that springs back when pressed, and no strong ammonia odor.
  • Fat content varies widely by species: lean fish (cod, tilapia, snapper) cook quickly and dry out easily; oily fish (salmon, mackerel, sardines) tolerate higher heat and longer cooking times.
  • Substitutions should consider texture and fat content rather than species name alone. For example, halibut can substitute for cod in most recipes, but mackerel cannot substitute for snapper.