Sardinella tawilis | |
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Sardinella tawilis being sold in a market. | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Clupeiformes |
Family: | Dorosomatidae |
Genus: | Sardinella |
Species: | S. tawilis |
Binomial name | |
Sardinella tawilis (Herre, 1927) | |
Synonyms [ citation needed ] | |
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Sardinella tawilis (the freshwater sardinella, freshwater herring, bombon sardine or freshwater sardine) is a freshwater sardine found exclusively in the Philippines. It is the only member of the genus Sardinella known to exist entirely in fresh water. [2] Locally, they are known in Filipino as tawilis. [2]
S. tawilis is listed in the Ark of Taste international catalogue of endangered heritage foods of Philippine cuisine by the Slow Food movement. [3]
In January 2019, the International Union for Conservation of Nature declared S. tawilis an endangered species. [4] [5] [6]
Sardinella is the diminutive of the Greek sarda, meaning literally "little sardine".
The species was originally identified and named in 1927 as Harengula tawilis by Albert William Herre, the Chief of the Fisheries Division of the Bureau of Science in Manila. The species was later moved to the more appropriate and taxonomically accurate genus, Sardinella . [2]
S. tawilis is a small fish reaching up to 15 cm and weighing less than 30 g. Like other members of their family, they have laterally compressed bodies with bellies covered in tough, scale-like scutes. They have a single, triangular dorsal fin and a forked caudal fin. They possess long, slender gill rakers in their mouths. [2]
S. tawilis populations are only found in Taal Lake in the Batangas province on the island of Luzon in the Philippines. Taal Lake is the third-largest lake in the Philippines and is located in the caldera of an ancient volcano. [7] It has an area of about 24,356.4 hectares (60,186 acres) and lies at nine municipalities and two cities. Near its center lies the 23.8-square-kilometer (9.2 sq mi) Volcano Island which has a 1.9-kilometer (1.2 mi) crater lake in the middle. The lake has a maximum depth of 180 meters (590 ft) and an average depth of 65 meters (213 ft). [8] Before recent history, the lake was but an extension of the entirely marine Balayan Bay, connected by a channel that narrowed through time and transpired as a river. [9] Major eruptions in the 18th century essentially sealed the lake from the sea, eventually leading its waters to become fresh water. S. tawilis is believed to be one of a few former marine species trapped within the lake that have evolved into purely freshwater species. [2]
S. tawilis, like members of its family, is an epipelagic filter feeder, using its gill rakers to strain plankton from the water while it swims with its mouth open. They roam the lake in large schools, just below the surface as the volcanic (and thus sedimentary) nature of the lake limits their plankton food to the surface.
The freshwater sardinella prefers to ingest larger prey, such as adult copepods, supplemented with rotifers and water fleas. During the summer months when the density of smaller copepods were much higher, their stomach contents consisted primarily of calanoid copepods, which are larger than the copepods blooming during this time. This suggests some partial control over prey selection exhibited by the fish, as opposed to simple filter-feeding. [10]
Little is known about their reproduction. [11] It is known that the Taal population spawns during the months of April to July, when surface temperatures are highest. [10]
The reproduction of the species saw a decline after the eruption of Taal Volcano in 2020. [12]
Despite its threatened status, [13] stocks in Lake Taal have been commercially fished for several decades. The fish is a widely popular food fish in the Philippines, and tons are shipped to most of the major cities in the country. Local supermarkets and wet markets usually have a tray or pile dedicated solely to the species.[ citation needed ]
The species is commonly referred to as tawilis in the local language of Tagalog. On the island of Cebu, one of the many places where tawilis is shipped, the native Cebuano name for the fish is tunsoy. [2]
In addition to raw consumption, tawilis is also processed into various food products. It is one of the many fish species dried, salted, and sold as daing in the country. They are also smoked and bottled in oil, and sold commercially.[ citation needed ]
In literature, Jose Rizal used three dried tawilis in his novel Noli Me Tangere to symbolize the Three Martyred Priests of Bagumbayan (Jose Burgos, Jacinto Zamora and Mariano Gomez).[ citation needed ]
Because of several factors, the species is threatened by overfishing. As with all species consisting of a single population in one location, a local extinction event will lead to species extinction. As the population of the Philippines grows, the demand will be greater for tawilis, possibly overfishing the lake's stock population. According to the IUCN Red List report which conducted last 28 February 2017 and published in 2018, the catch of the tawilis started to decline since 1998 due to overfishing, illegal use of active fishing gears, increasing use of fish cages, and the deterioration of the water quality in Taal Lake. The harvest of the tawilis has said to declined by at least 50 percent over the past 10 years. Because of this, the IUCN listed the tawilis as endangered. [1] [4] [5] [6]
In February 2021, some tawilis were taken out of Taal Lake due to Taal Volcano's increasing volcanic activity. The conservation project led and funded by the Department of Science and Technology's Council for Agriculture, Aquatic, and Natural Resources Research and Development resettled the tawilis at University of the Philippines Los Baños's Limnological Station. [14]
Herring are forage fish, mostly belonging to the family of Clupeidae.
Atlantic herring is a herring in the family Clupeidae. It is one of the most abundant fish species in the world. Atlantic herrings can be found on both sides of the Atlantic Ocean, congregating in large schools. They can grow up to 45 centimetres (18 in) in length and weigh up to 1.1 kilograms (2.4 lb). They feed on copepods, krill and small fish, while their natural predators are seals, whales, cod and other larger fish.
Sardine and pilchard are common names for various species of small, oily forage fish in the herring suborder Clupeoidei. The term 'sardine' was first used in English during the early 15th century; a somewhat dubious etymology says it comes from the Italian island of Sardinia, around which sardines were once supposedly abundant.
The ciscoes are salmonid fish that differ from other members of the genus Coregonus in having upper and lower jaws of approximately equal length and high gill raker counts. These species have been the focus of much study recently, as researchers have sought to determine the relationships among species that appear to have evolved very recently. Cisco is also specifically used for the North American species Coregonus artedi, also known as lake herring.
Taal Lake, formerly known as Bombón Lake, is a fresh water caldera lake in the province of Batangas, on the island of Luzon in the Philippines. The lake fills Taal Volcano, a large volcanic caldera formed by very large eruptions between 500,000 and 100,000 years ago.
Lake Lanao is a large ancient lake in the province of Lanao del Sur, Philippines. With a surface area of 340 km2 (130 sq mi), it is the largest lake in Mindanao, the deepest and second largest lake in the Philippines, and counted as one of the 15 ancient lakes in the world. Scholars have been pushing for the lake's inclusion in the UNESCO World Heritage List. The lake's native people call themselves the Maranao or Meranaw. Their name was derived from the name of the lake, meaning "the people living around the lake".
Taal, officially the Municipality of Taal, is a 3rd class municipality in the province of Batangas, Philippines. According to the 2020 census, it has a population of 61,460 people.
The Pansipit River is a short river located in the Batangas province of the Philippines. The river is the sole drainage outlet of Taal Lake, which empties to Balayan Bay. The river stretches some 9 kilometers (5.6 mi) passing along the municipalities of Agoncillo, Lemery, San Nicolas, and Taal, serving as a boundary between the communities. It has a very narrow entrance from Taal Lake.
Sardinella is a genus of fish in the family Dorosomatidae found in the Atlantic, Indian and Pacific Ocean. They are abundant in warmer waters of the tropical and subtropical oceans. Adults are generally coastal, schooling, marine fish but juveniles are often found in lagoons and estuaries. These species are distinguished by their ranges and by specific body features, but they are often confused with one another. Fish of the genus have seven to 14 striped markings along the scales of the top of the head. The paddle-shaped supramaxilla bones are characteristic; they separate Sardinella from other genera and their shapes help distinguish species. They have paired predorsal scales and enlarged fin rays.
Bostrychus expatria is a species of freshwater fish in the family Butidae endemic to Lake Manguao on the island of Palawan in the Philippines.
The Lake Tanganyika sardine is a species of freshwater fish in the family Dorosomatidae which was endemic to Lake Tanganyika but which has now been introduced to other lakes in Africa as a food source. It is monotypic within the genus Limnothrissa. It and the Lake Tanganyika sprat are known collectively as kapenta.
A wild fishery is a natural body of water with a sizeable free-ranging fish or other aquatic animal population that can be harvested for its commercial value. Wild fisheries can be marine (saltwater) or lacustrine/riverine (freshwater), and rely heavily on the carrying capacity of the local aquatic ecosystem.
Forage fish, also called prey fish or bait fish, are small pelagic fish that feed on planktons and other small aquatic organisms. They are in turn preyed upon by various predators including larger fish, seabirds and marine mammals, this making them keystone species in their aquatic ecosystems.
The UPLB Limnological Research Station traces its root from the Department of Entomology, of the then UP College of Agriculture. Since its conception, the station contributed immensely to the understanding of the bounties of Laguna de Bay and helped establish the duck farming industry on Los Baňos foreshores and pioneered in aquarium fish production in the country. It serves as the base for studies on limnology and biology of aquatic organisms aimed at developing strategies for the optimum utilization and sustained production of aquatic resources; developing, adapting or improving conventional technologies used to increase fish production; and promoting environment friendly approaches for effective water management.
The wildlife of the Philippines includes a significant number of endemic plant and animal species. The country's surrounding waters reportedly have the highest level of marine biodiversity in the world. The Philippines is one of the seventeen megadiverse countries and is a global biodiversity hotspot. In 2013, 700 of the country's 52,177 species were listed as threatened.
The European pilchard is a species of ray-finned fish in the monotypic genus Sardina. The young of the species are among the many fish that are sometimes called sardines. This common species is found in the northeast Atlantic, the Mediterranean, and the Black Sea at depths of 10–100 m (33–328 ft). It reaches up to 27.5 cm (10.8 in) in length and mostly feeds on planktonic crustaceans. This schooling species is a batch spawner where each female lays 50,000–60,000 eggs.
Gilchristella aestuaria, the Gilchrist's round herring or estuarine round-herring, is a member of the herring family Clupeidae that occurs off the coasts of Southern Africa. It is the only species in its genus, which was named for John Dow Fisher Gilchrist (1866–1926).
The following outline is provided as an overview of and topical guide to fish:
Saltwater fish, also called marine fish or sea fish, are fish that live in seawater. Saltwater fish can swim and live alone or in a large group called a school.
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