Whale shark

📖 Overview

World's largest fish, but is harmless to humans . Grows up to 20m . Often seen offshore but coming close inshore, sometimes entering lagoons or coral atolls . Sometimes seen cruising near outer wall . Reported to frequent shallow water areas near estuaries and river mouths, sometimes during seasonal shrimp blooms . Found singly, or in aggregations of over 100 individuals . Often associated with groups of pelagic fishes, especially scombrids . Highly migratory between ocean basins and national jurisdictions, but returns to the same sites annually. Feed on planktonic and nektonic prey, such as small fishes (sardines, anchovies, mackerel, juvenile tunas and albacore), small crustaceans and squids . Often seen in a vertical position with the head at or near the surface when feeding . When actively feeding on zooplankton the sharks turn their heads from side to side, with part of the head lifted out of the water, and the mouth opened and closed 7-28 times per minute; these suction gulps were synchronized with the opening and closing of the gill slits . Ovoviviparous, with litter size of over 300 pups . Females of 438 to 562 cm are immature (FIGIS 09/2003). Utilized fresh, frozen, dried and salted for human consumption, liver processed for oil, fins used for shark-fin soup, offal probably for fishmeal , cartilage for health supplements and skin for leather products . Used in Chinese medicine . Highly valued commodity in ecotourism operations. Populations have been depleted in several countries by harpoon fisheries . Estimated longevity of 80.4 yrs is much larger than reported maximum age 38 yrs based on vertebral bands for a female of 11.9 m TL. Maximum length of up to 21 m and weight of up to 42 tons have been reported , but probably the most reliably measured size so far is 12 m TL .

🔬 Taxonomy

🐟 Physical Description

Dorsal spines (total): 0; Anal spines: 0. A huge, filter-feeding, blunt-headed shark with a distinct checkerboard pattern of yellow or white spots, on grey, bluish or blue-grey to green-brown back, white or yellowish underside, with horizontal and vertical stripes on back and sides of body; head broad and flat; snout short; mouth almost terminal, huge and transverse in front of eyes; prominent ridges on body, lowest terminating in a keel on caudal peduncle ; nostrils with rudimentary barbels; long nasoral grooves; spiracles close to and larger than eyes; 5 exceptionally large gill openings, the fifth behind pectoral fin ; numerous small, scale-like teeth and feeds by filtering plankton with special sieve-like modifications of the gill bars .: elongated; Cross section: other (see remarks).

🌀 Behaviour

Behavioural data for Whale shark is currently being reviewed.

🦐 Diet

The whale shark is a filter feeder – one of only three known filter-feeding shark species (along with the basking shark and the megamouth shark). It feeds on plankton including copepods, krill, chaetognaths, jellyfish, fish eggs, Christmas Island red crab larvae and small nektonic life, such as small squid or fish (sardines, anchovies, mackerels and small tunas). It also feeds on clouds of eggs during mass spawning of fish and corals. In addition, they have been found to ingest and partially digest Sargassum, thus making them omnivores. The many rows of vestigial teeth play no role in feeding. Feeding occurs either by ram filtration, in which the animal opens its mouth and swims forward, pushing water and food into the mouth, or by active suction feeding, in which the animal opens and closes its mouth, sucking in volumes of water that are then expelled through the gills. In both cases, the filter pads serve to separate food from water. These unique, black sieve-like structures are presumed to be modified gill rakers. Food separation in whale sharks is by cross-flow filtration, in which the water travels nearly parallel to the filter pad surface, not perpendicularly through it, before passing to the outside, while denser food particles continue to the back of the throat. This is an extremely efficient filtration method that minimizes fouling of the filter pad surface. Whale sharks have been observed "coughing", presumably to clear a build-up of particles from the filter pads. Whale sharks migrate to feed and possibly to breed. The whale shark is an active feeder, targeting concentrations of plankton or fish. It is able to ram filter feed or can gulp in a stationary position. This is in contrast to the passive feeding basking shark, which does not pump water.

🥚 Reproduction

Distinct pairing with embrace . Ovoviviparous . Embryos feed solely on yolk . Late term embryos shed their egg case within the uterus at a size of 58 to 64 cm TL (ovovivipary). The smallest free-living species are from 55-56 cm long, the smallest of which had an umbilical scar. A pregnant female has recently been found with 300 embryos, the largest of which were 58-64 cm.

🌍 Habitat & Distribution

Marine; pelagic-oceanic; oceanodromous ; depth range 0 - 1928 m , usually 0 - 100 m . Subtropical; 18°C - 30°C ; 45°N - 48°S, 180°W - 180°E

🌿 Ecology

📐 Morphometrics

🌡️ Water Parameters & Tolerance

🛡️ Conservation Assessment

📊 Population Risk & Fisheries

🍽️ Edibility & Flavour

"Whale shark is an edible species."

⚡ Nutrition

Detailed nutritional data for Whale shark is currently being compiled from USDA FoodData Central.

🔬 Mercury Safety

Mercury data for Whale shark has not yet been assigned. Please consult FDA/EPA guidance for general seafood safety advice.

🌿 Sustainability

🌐 Names & Taxonomy

Scientific Synonyms

🗺️ Global Occurrence Map

Occurrence records from the Global Biodiversity Information Facility (GBIF) — 19 records indexed .

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