Reference Terms
from Wikipedia, the free encyclopedia
Perch
Perca is the genus of fish referred to as perch or yellow perch, a group of freshwater fish belonging to the family Percidae. Perch have "rough" or ctenoid scales. When looking through a microscope, the scale look like a plate with growth rings and spikes on the top edges. Externally the anatomy of perch is simple enough. On the dorsal side of the fish, there consists a upper maxilla and lower mandible for the mouth, a pair of nostrils, and two lidless eyes. On the posterior sides are the operculum, which are used to protect the gills. Also there is the lateral line system which is sensitive to vibrations in the water. They have a pair of pectoral and pelvic fins. On the anterior end of the fish, there are two dorsal fins. The first one is spiny and the second is soft. There is also an anal fin, which is also considered spiny, and a caudal fin. Also there is a cloacal opening right behind the anal fin.
Related Stories
1
2
Plants & Animals News
December 28, 2025
Dec. 28, 2025 When researchers lowered whale bones into the deep ocean, they expected zombie worms to quickly move in. Instead, after 10 years, none appeared — an unsettling result tied to low-oxygen waters in the region. These worms play a key role in breaking ...
Dec. 27, 2025 UBC Okanagan researchers have uncovered how plants create mitraphylline, a rare natural compound linked to anti-cancer effects. By identifying two key enzymes that shape and twist molecules into their final form, the team solved a puzzle that had ...
Dec. 24, 2025 The search for life on Earth is speeding up, not slowing down. Scientists are now identifying more than 16,000 new species each year, revealing far more biodiversity than expected across animals, plants, fungi, and beyond. Many species remain ...
Dec. 22, 2025 Washing machines release massive amounts of microplastics into the environment, mostly from worn clothing fibers. Researchers at the University of Bonn have developed a new, fish-inspired filter that removes over 99% of these particles without ...
Dec. 22, 2025 A Brazilian study has confirmed that Joseph’s Coat, a plant used for generations in folk medicine, can significantly reduce inflammation and arthritis symptoms in lab tests. Researchers observed less swelling, healthier joints, and signs of tissue ...
Dec. 21, 2025 Old military air samples turned out to be a treasure trove of biological DNA, allowing scientists to track moss spores over 35 years. The results show mosses now release spores up to a month earlier than in the 1990s. Even more surprising, the ...
Dec. 16, 2025 Scientists are uncovering a surprising way to influence bacteria—not by killing them, but by changing how they communicate. Researchers studying oral bacteria found that disrupting chemical signals used in bacterial “conversations” can shift ...
Dec. 14, 2025 Senescent “zombie” cells are linked to aging and multiple diseases, but spotting them in living tissue has been notoriously difficult. Researchers at Mayo Clinic have now taken an inventive leap by using aptamers—tiny, shape-shifting DNA ...
Dec. 14, 2025 Forskolin, a plant-derived compound, shows surprising potential against one of the most aggressive forms of leukemia. Researchers discovered that it not only stops cancer cells from growing but also makes them far more vulnerable to chemotherapy by ...
Dec. 13, 2025 Researchers analyzing ancient fossils from caves across Western Australia have uncovered a completely new species of bettong along with two new woylie subspecies—remarkable finds made bittersweet by signs that some may already be ...
Dec. 12, 2025 New research shows that crops are far more vulnerable when too much rainfall originates from land rather than the ocean. Land-sourced moisture leads to weaker, less reliable rainfall, heightening drought risk. The U.S. Midwest and East Africa are ...
Dec. 12, 2025 A sudden, unexplained mass die-off is decimating sea urchins around the world, including catastrophic losses in the Canary Islands. Key reef-grazing species are reaching historic lows, and their ability to reproduce has nearly halted in some ...
Latest Headlines
updated 12:56 pm ET
Dec. 28, 2025 Scientists have uncovered why big predators like sharks spend so much time in the ocean’s twilight zone. The answer lies with mid-sized fish such as the bigscale pomfret, which live deep during the ...
Dec. 25, 2025 A tiny fish long feared lost has resurfaced in Bolivia, offering a rare conservation success story amid widespread habitat destruction. Moema ...
Dec. 25, 2025 A major evolutionary theory says most genetic changes don’t really matter, but new evidence suggests that’s not true. Researchers found that helpful mutations happen surprisingly often. The twist ...
Dec. 22, 2025 Some ants thrive by choosing numbers over strength. Instead of heavily protecting each worker, they invest fewer resources in individual armor and produce far more ants. Larger colonies then ...
Dec. 21, 2025 Researchers have found that fossilized dinosaur eggshells contain a natural clock that can reveal when dinosaurs lived. The technique delivers surprisingly precise ages and could revolutionize how ...
Dec. 20, 2025 Balanophora is a plant that abandoned photosynthesis long ago and now lives entirely as a parasite on tree roots, hidden in dark forest undergrowth. ...
Dec. 19, 2025 Long before whales and sharks, enormous marine reptiles dominated the oceans with unmatched power. Scientists have reconstructed a 130-million-year-old marine ecosystem from Colombia and found ...
Dec. 19, 2025 Researchers announced over 70 new species in a single year, including bizarre insects, ancient dinosaurs, rare mammals, and deep-river fish. Many were found not in the wild, but in museum ...
Dec. 18, 2025 Researchers have uncovered that the body uses different molecular systems to sense cold in the skin versus internal organs. This explains why surface chills feel very different from cold experienced ...
Dec. 18, 2025 California researchers are preparing for the possible return of the New World screwworm, a parasitic fly that feeds on living flesh and once devastated U.S. livestock. By monitoring traps and ...