Pandaka pygmaea
Encyclopedia
The dwarf pygmy goby is a tropical freshwater fish
of the family
Gobiidae. It is one of the smallest fish in the world by mass, and is also one of the shortest freshwater fish. Mature males can reach up to 1.1 cm, while the females can grow up to 1.5 cm. Average weight is from 4 to 5 mg. It is known as bia and tabios in the Philippines
.
. It used to frequent shady river banks in Rizal Province of Luzon, Philippines. It has also been collected in the sea at Culion Island, near Palawan
, Philippines. It also thrives in brackish waters and mangrove
areas of Indonesia
, and Singapore
(1992). It had been imported into Germany
in 1958.
Dwarf pygmy gobies survive in demersal, freshwater
, brackish and marine
water environments at a pH
ranging from 7.0 – 8.4, a dH
range of 30, and at tropical temperatures measuring from 24 to 30 °C.
The head of the P. pygmaea is large and blunt. The head and nape are naked. The upper and lower profiles converge and are pointed if viewed from the sides. The head is characteristically broader than deep. The head is very short, broad and rounded. The mouth is very oblique, with a projecting lower jaw and chin. The posterior angle of the maxillary extends beneath the anterior part of the eye, up to the middle of pupil. It possesses two rows of teeth in each jaw. The outer row of teeth inside the upper jaw is larger and more widely spaced, while the inner row is characteristically minute. The first dorsal fin is low, much in advance of the second dorsal fin but not reaching the second dorsal fin when depressed. The pectoral and ventral fins are pointed, with the latter about as long as the former or longer. The anal papilla is very short and rounded in females, but is longer and very slender in males.
P. pygmaea have dark spots, which forms 4 cross-bands, over the sides of its body. The bases of the fins are heavily pigmented, except for the ventral fins. It has 22 to 25 scales in longitudinal series.
due to polluted local water
s or land reclamation projects.
coin. The genus name is derived from the Filipino
word pandak, meaning "dwarf" or "short of stature".
Freshwater fish
Freshwater fish are fish that spend some or all of their lives in freshwater, such as rivers and lakes, with a salinity of less than 0.05%. These environments differ from marine conditions in many ways, the most obvious being the difference in levels of salinity...
of the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Gobiidae. It is one of the smallest fish in the world by mass, and is also one of the shortest freshwater fish. Mature males can reach up to 1.1 cm, while the females can grow up to 1.5 cm. Average weight is from 4 to 5 mg. It is known as bia and tabios in the Philippines
Philippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
.
Distribution and habitat
P. pygmaea is primarily a Philippine species that was endemic in the rivers of Malabon, Metro ManilaMetro Manila
Metropolitan Manila , the National Capital Region , or simply Metro Manila, is the metropolitan region encompassing the City of Manila and its surrounding areas in the Philippines...
. It used to frequent shady river banks in Rizal Province of Luzon, Philippines. It has also been collected in the sea at Culion Island, near Palawan
Palawan
Palawan is an island province of the Philippines located in the MIMAROPA region or Region 4. Its capital is Puerto Princesa City, and it is the largest province in the country in terms of total area of jurisdiction. The islands of Palawan stretch from Mindoro in the northeast to Borneo in the...
, Philippines. It also thrives in brackish waters and mangrove
Mangrove
Mangroves are various kinds of trees up to medium height and shrubs that grow in saline coastal sediment habitats in the tropics and subtropics – mainly between latitudes N and S...
areas of Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
, and Singapore
Singapore
Singapore , officially the Republic of Singapore, is a Southeast Asian city-state off the southern tip of the Malay Peninsula, north of the equator. An island country made up of 63 islands, it is separated from Malaysia by the Straits of Johor to its north and from Indonesia's Riau Islands by the...
(1992). It had been imported into Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
in 1958.
Dwarf pygmy gobies survive in demersal, freshwater
Freshwater
Fresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Fresh water is generally characterized by having low concentrations of dissolved salts and...
, brackish and marine
Marine (ocean)
Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...
water environments at a pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
ranging from 7.0 – 8.4, a dH
DH
-Flying:* de Havilland, a former UK aircraft manufacturer* Decision height, an element of aviational instrument approach* Independence Air's IATA code-Health:* Department of Health , a branch of government...
range of 30, and at tropical temperatures measuring from 24 to 30 °C.
Appearance and anatomy
A colorless and nearly transparent species, the dwarf pygmy goby has a moderately elongated and robust body. Males are slender with nearly straight dorsal and ventral profiles, while the females appear stouter with the dorsal profile slightly curved, the belly protuberant, and the ventral outline strongly arched.The head of the P. pygmaea is large and blunt. The head and nape are naked. The upper and lower profiles converge and are pointed if viewed from the sides. The head is characteristically broader than deep. The head is very short, broad and rounded. The mouth is very oblique, with a projecting lower jaw and chin. The posterior angle of the maxillary extends beneath the anterior part of the eye, up to the middle of pupil. It possesses two rows of teeth in each jaw. The outer row of teeth inside the upper jaw is larger and more widely spaced, while the inner row is characteristically minute. The first dorsal fin is low, much in advance of the second dorsal fin but not reaching the second dorsal fin when depressed. The pectoral and ventral fins are pointed, with the latter about as long as the former or longer. The anal papilla is very short and rounded in females, but is longer and very slender in males.
P. pygmaea have dark spots, which forms 4 cross-bands, over the sides of its body. The bases of the fins are heavily pigmented, except for the ventral fins. It has 22 to 25 scales in longitudinal series.
Ecology
The species is considered vanishing or extinct in the PhilippinesPhilippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
due to polluted local water
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
s or land reclamation projects.
Miscellaneous
Pandaka pygmaea was once portrayed on a Philippine ten centavoCentavo
Centavo is a Spanish and Portuguese word, derived from the Latin centum, meaning "one hundred", and the suffix -avo, meaning "portion" or "fraction"...
coin. The genus name is derived from the Filipino
Filipino language
This move has drawn much criticism from other regional groups.In 1987, a new constitution introduced many provisions for the language.Article XIV, Section 6, omits any mention of Tagalog as the basis for Filipino, and states that:...
word pandak, meaning "dwarf" or "short of stature".
See also
- Seven-figure pygmy gobySeven-figure pygmy gobySeven-figure pygmy goby , a tiny coral reef-dwelling fish, has the shortest lifespan for a vertebrate. This species can only live for 59 days.- References :* - External links :*...
- Philippine EaglePhilippine EagleThe Philippine Eagle , also known as the Monkey-eating Eagle, is an eagle of the family Accipitridae that is endemic to forests in the Philippines. It has brown and white-coloured plumage, and a shaggy crest, and generally measures in length and weighs...
External links
- Chen, Loris. Gobies: Going, Going, Gone? A WebQuest for 6-8th Grade (Science) (lchen@wyckoffschools.org), Ocean Biographic Information System, Census of Marine Life, Rutgers, The State University of New Jersey, 2002-2007. IOBIS.org, retrieved on July 14, 2007
- Fenner, Bob. "True" or Combtooth Gobies, the Family Gobiidae, Wetwebmedia.com (undated), retrieved on July 14, 2007