California sheephead

The California sheep head (Semicossyphus pulcher) is a species of wrasse native to the eastern Pacific Ocean. Its range is from Monterey Bay, California, to the Gulf of California, Mexico.[5] This species can live for up to 20 years in favorable conditions and can reach a size of up to 91 cm (3 ft) and a weight of 16 kg (35 lb).[5] They are carnivorous, living in rocky reef and kelp bed habitats, feeding primarily on sea urchins, molluscs, and crustaceans.

All California sheephead are born female and morph into their male form at various stages in their lifecycle, determined by environmental conditions and pressures. Because of this, they are considered to be protogynous hermaphrodites which have planktonic larvae. Their coral and kelp-heavy habitat provides protection from predators, which is important as this species is diurnal, foraging during the day and seeking shelter at night.

The California sheephead is considered vulnerable due to high fishing rates off of the coast of southern California. Since fisheries tend to remove the largest fish, they end up removing the males. This skews the male-to-female ratio and affects the fishes' lifecycle, which can negatively affect populations.[6][7]

California sheephead
Sheephead photo
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Labriformes
Family: Labridae
Genus: Semicossyphus
Günther, 1861
Species:
S. pulcher
Binomial name
Semicossyphus pulcher
(Ayres, 1854)
Synonyms
  • Labrus pulcher Ayres, 1854[2]
  • Semicossyphus pulcher Günther, 1861[3]
  • Pimelometopon pulcher Gill, 1854[4]

Description

Male and female California sheepsheads have different color patterns and body shapes.[5] Males are larger, with black tail and head sections, wide, reddish orange midriffs, red eyes, and fleshy forehead bumps.[8] Female sheephead are dull pink with white undersides.[8] Both sexes have white chins and large, protruding canine teeth that can pry hard-shelled animals from rocks or inflict nasty puncture wounds on skin divers.[8] After powerful jaws and sharp teeth crush the prey, modified throat bones (a throat plate) grind the shells into small pieces.[8] California sheephead can reach a size of 91 cm (3 ft) and a weight of 16 kg (35 lb).[5] All sheepheads are born as females and eventually change to males at roughly 45 cm (1.5 ft).[5] The age of the transition depends on environmental factors such as food supply.[5] When supplied with a large amount of food, the California sheephead can live for up to 21 years. If food is scarce, they can live up to 9 years.[8]

Etymology

Semicossyphus is Greek; semi means half and kossyphos means a kind of fish. Pulcher is the Latin word for beautiful.[5] In French, the fish is called the labre Californien, and in Spanish it is called the vieja de California.[9]

Biology

The California sheephead lives in kelp forests and rocky reefs, where it feeds on sea urchins, molluscs, lobsters, and crabs. Fertilized eggs are released into the water column and hatch, resulting in planktonic larva.[5]

Like many wrasse species, sheephead are protogynous. All are born female, and the largest individuals become male due to hormonal changes triggered by social cues. The two sexes have extremely different appearances, so this transition is among the most dramatic among the wrasses. Because only large individuals are male, setting minimum catch sizes has made populations mostly female, with a negative effect on population sizes.[10]

Distribution and habitat

Home ranges in California sheephead vary greatly, and this variability can be attributed to differences in habitat shape (embayment versus contiguous coastline) and to natural habitat boundaries (deep, sandy expanses).[11] They are found in rocky-reef areas 54% of the time, and within those areas, a greater percentage of daytime is found in high relief areas.[11] Although their home ranges are thought of as particularly well defined, the size and fidelity may vary ontogenetically and seasonally and with habitat availability.[11] Sheephead home ranges are relatively small, and the fish have a very high site attachment.[11] They may select rocky areas with kelp most often due to the increased habitat complexity, which likely offers additional feeding opportunities and potential refuge from large predators.[11] Sheephead generally are considered mainly a rocky-reef and kelp-bed associated species, but they occasionally frequent sand habitats in foraging forays.[11]

Ecology

California sheephead are monandric protogynous hermaphrodites and are commercially and recreationally valuable labrids.[12] They are a prominent species occupying the southern California rocky reef and kelp bed fish assemblage.[11][13] Both the ecology and life history patterns of California sheephead have been shown to vary with local environmental conditions.[14]

Feeding

California sheephead are carnivorous, epibenthic reef fish, foraging mostly in the daytime in sand-rock reef habitats.[12] Their feeding territories are very productive and allow individuals to occupy small, permanent, economically defendable home ranges.[15] As a large temperate wrasse, they are predators of sea urchins and other benthic invertebrates and play a critical role in also regulating prey populations in kelp forests.[16] Since they feed heavily on urchins, they are consequently an important species for indirectly regulating kelp growth in southern California’s coastal waters.[12] However, they exhibit flexibility in prey selection if their main food source is not readily available at a particular time.[14] Populations with diets dominated by crabs and sea urchins, however, reach larger sizes and mature and change sex at larger sizes than populations that consume higher proportions of bivalves, barnacles, and bryozoans.[16] Since they forage in the daytime and are considered a diurnal species, they may rely on anatomical characteristics which allow them to feed in exposed locations in broad daylight while overcoming the defenses evolved by their prey.[17] They forage both in groups and alone, and larger fish tend to shift towards more heavily armored prey.[11][17]

Predation

As a reef fish, signals about the sheephead’s predation risk often comes from the presence of damage-released chemical cues produced by injured prey animals.[18] These clues are only released when the skin is ruptured, and act as a reliable indicator of the presence of an actively foraging predator.[18] Chemical cues may be released not only with injury, but also when pathogens or parasites penetrate the skin; therefore, the reliability of the chemical cues as indicators of predation risk is decreased.[18] When a sheephead is captured by a predator, and damage-released chemical cues are discharged, the information is available for both conspecifics and heterospecifics to use.[18]

Fishy fishy
California sheephead showing teeth in kelp bed habitat

Migration and territoriality

The behavior of California sheephead is shaped by the daily cycle of light, twilight, and dark.[17] Diurnal fishes, like the sheephead, make a round trip between their refuges and foraging areas twice a day, and additional daily trips may be made by breeding fishes to spawning sites.[15] This elaborate diel timing of movements is driven by the need to forage or mate while minimizing predation.[15] Patterns in the movement of California sheephead are mediated by fish sex and size; for example, large males will exhibit higher site fidelity than females.[13][14] However, males also show wider ambits than females, and the size of their ambits changes seasonally.[14] During spawning season, males show a daily increase in their ambits during a period of potential spawning, and also make daily journeys offshore into deeper water.[14] Females (which would be expected to move more frequently among male territories) do not expand their ambits significantly during this same period.[14] Each of the movements offshore by males is followed by a return to nearshore habitat prior to twilight, suggesting the occupation of a spawning territory at that time.[14] At twilight, continuing to about 10 to 15 minutes after sunset, the degree of activity above the reef rapidly decreases and sheephead seek shelter for the night; this ‘quiet’ period is a time of major activity for larger reef predators.[17]

Male and female California sheephead have overlapping home ranges; although they are not usually considered a territorial species, male sheephead can exhibit territorial behavior.[11] Male sheephead are increasingly territorial throughout the day during periods of spawning activity.[11] Since spawning activity occurs around sunset, it may be that they only have differences in space use for short periods on various days during the spawning season, thus male territoriality only occurs in this same timespan.[11]

Breeding and lifecycle

California sheephead populations vary spacially in reproductive potential and reproductive capacity, and these differences are correlated with the natural sea surface temperature gradient.[19] Fish in cooler waters may require less energy for growth and may be able to convert more energy into reproduction than fish at warmer sites.[16][19] Population densities and sex ratios of hermaphroditic fishes are also intimately linked to ecological factors and human activities.[19] Spatial and temporal changes in fishing pressure, coupled with environmental changes across populations over time, tend to affect the reproductive potential of each population of California sheephead.[19] Spatially separate populations of California sheephead vary in their sex ratios (number of females to number of males), in size of individuals at sex change, and in the sex ratio threshold.[19] Sheephead are also haremic spawners, meaning each male defends a group of females with which he breeds.[13]

Sex change

California sheephead can transition from a reproductively functional female to a functional male during the course of a lifespan in response to social factors.[12] Protogynous sex change typically follows the size-advantage model, where gonadal transformation occurs once the reproductive potential of an individual would be greater as a male than as a female.[19] The transitional phase takes between two weeks and several months, and steroid hormone concentrations are thought to be related to sex change due to the total degradation of the ovaries and the appearance of testes.[12] The exact timing of the sexual morphogenesis is suppressed by aggressive interactions with dominant males and triggered by the removal of alpha males.[20] There is a period of reproductive inactivity during gonadal remodeling, and the sex change in this species is unidirectional.[12] In later stages of the transition, fish possibly are functionally male, but maintain an intersexual gonadal appearance.[12]

Fishmarket 01
California sheephead at fish market

Human interaction

The fishery for this species, which began in at least the late 1800s (for salted fish), peaked in 1928 with landings of 370,000 lb (170,000 kg).[9] This may have been because the species was easily available close to port, and has maintained a presence in the California nearshore fishery.[9] From the 1940s to 1980s, little interest in the sheephead was shown, and catches were usually under 10,000 lb (4,500 kg).[9] In the later 1980s, commercial fisheries began to supply live fish to Asian markets and restaurants.[8] The fisheries grew rapidly, with sheephead becoming a large share of the catches. Because restaurant aquariums are small, commercial fisheries seek small, juvenile sheephead, usually females before they have reproduced.[8]

California sheephead are fished by anglers and spearfishers for food, and are caught live for the aquarium trade.[21] The recreational and commercial catch of sheephead in 1999 was estimated at over 132,000 fish.[21] Mainly juveniles are included in important commercial trap fishery, with juveniles and smaller adults dominating the hook and line and recreational fishery.[9] In 2009, fishing vessels generated $333,801 in revenue from sheephead, much of that due to the lucrative live fish industry in Asian markets.[21] California sheephead are economically valuable as keystone predators on purple sea urchins and red sea urchins, keeping them from overgrazing kelp forests.[21] Thus, where they are present, sheephead contribute to the growth and biodiversity of kelp forests, and the corresponding increase in populations of other commercially valuable fish species that are dependent on kelp habitat, such as kelp bass and white seabass.[21]

Conservation status

The California sheephead is considered a vulnerable species because of its high fishing rates off of the coast of Southern California.[5] Usually most of the fish caught are the largest males, causing a shortage in males in the population and the subsequent morphogenesis of the largest females to males.[9] This, in turn, creates a deficiency in the number of eggs produced and weakens the population in a particular fishing area.[20] Male numbers seem typically low which also could result in sperm limitation for the species, with further male reduction, resulting in reduced reproductive output: males are readily targeted in the recreational spear fishery.[9] Commercial and recreational fishing pressure has increased (there is also an artisanal sector), and this has caused catches to decline over the last decade.[9] To control the catches of sheephead and prevent overfishing, the California Department of Fish and Game in 2001 established regulations that restrict the catch size of sheephead and the areas where these fish may be caught.[8]

Size restrictions on sheephead were fairly minimal before 1999 for both the recreational and commercial fisheries. But, in 1999, CDFG set the minimum catch size for the commercial fishery to 12 in or 30 cm (total length) and followed with the same size limit for the recreational fishery in 2001.[9] To further decrease commercial harvest, the minimum commercial harvest size was increased to 13 in 2001 and the 10-fish recreational bag limit was reduced to five.[9]

References

  • "Semicossyphus pulcher". Integrated Taxonomic Information System. Retrieved 18 April 2006.
  1. ^ Cornish, A. & Dormeier, M. (Grouper & Wrasse Specialist Group) 2006. Semicossyphus pulcher. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.1. <www.iucnredlist.org Archived 27 June 2014 at the Wayback Machine>. Downloaded on 16 November 2013.
  2. ^ Ayres, W. O. (1854). "[Description of new fishes from California]". Proceedings of the California Academy of Sciences. 1: 3–4.
  3. ^ Günther, Albert (1861). "A Preliminary Synopsis of the Labroid Genera". Annals and Magazine of Natural History. Ser. 3. 8 (47): 384. doi:10.1080/00222936108697435.
  4. ^ Gill, Theodore (1864). "Description of a New Labroid Genus Allied to Trochocopus Gthr". Proceedings of the Academy of Natural Sciences of Philadelphia. 16 (2): 57–59. JSTOR 4623897.
  5. ^ a b c d e f g h i Froese, Rainer and Pauly, Daniel, eds. (2006). "Semicossyphus pulcher" in FishBase. February 2006 version.
  6. ^ Braje, Todd J.; Rick, Torben C.; Szpak, Paul; Newsome, Seth D.; McCain, Joseph M.; Elliott Smith, Emma A.; Glassow, Michael; Hamilton, Scott L. (February 2017). "Historical ecology and the conservation of large, hermaphroditic fishes in Pacific Coast kelp forest ecosystems". Science Advances. 3 (2): e1601759. doi:10.1126/sciadv.1601759. ISSN 2375-2548.
  7. ^ Hamilton, S. L.; Caselle, J. E. (2014-12-10). "Exploitation and recovery of a sea urchin predator has implications for the resilience of southern California kelp forests". Proceedings of the Royal Society B: Biological Sciences. 282 (1799): 20141817–20141817. doi:10.1098/rspb.2014.1817. ISSN 0962-8452.
  8. ^ a b c d e f g h "California sheephead". Archived from the original on 2 December 2013.
  9. ^ a b c d e f g h i j Cornish, A. "Semicossyphus pulcher". IUCN.
  10. ^ Hamilton, Scott L.; J.E. Caselle; J.D. Standish; D.M. Schroeder; M.S. Love; J.A. Rosales-Casian; O. Sosa-Nishizaki (2007). "Size-selective harvesting alters life histories of a temperate sex-changing fish" (PDF). Ecological Applications. 17 (8): 2268–80. doi:10.1890/06-1930.1.
  11. ^ a b c d e f g h i j k Topping, D. T. (2005). "Home range and habitat utilization of adult California sheephead, Semicossyphus pulcher (Labridae), in a temperate no-take marine reserve". Marine Biology. 147: 301–311. doi:10.1007/s00227-005-1573-1.
  12. ^ a b c d e f g Sundberg, Michael (2009). "Gonadal Restructuring During Sex Transition in California Sheephead: a Reclassification Three Decades After Initial Studies". Bulletin, Southern California Academy of Sciences. 108 (1): 16–28. doi:10.3160/0038-3872-108.1.16. PMC 4386901.
  13. ^ a b c Froeschke, John (2006). "The Fish Assemblages Inside and Outside of a Temperate Marine Reserve in Southern California". Bulletin, Southern California Academy of Sciences. 105 (3): 128–142. doi:10.3160/0038-3872(2006)105[128:tfaiao]2.0.co;2.
  14. ^ a b c d e f g Lindholm, James (2010). "Gender-Mediated Patterns in the Movement of California Sheephead in the Northern Channel Islands (Eastern Pacific)". California Fish and Game. 96 (1): 53–68.
  15. ^ a b c Godin, Jean-Guy (1997). Behavioral Ecology of Teleost Fishes. Oxford: Oxford University Press.
  16. ^ a b c Hamilton, Scott (September 2011). "Utilizing Spatial Demographic and Life History Variation to Optimize Sustainable Yield of a Temperate Sex-Changing Fish". PLoS ONE. 6 (9): e24580. doi:10.1371/journal.pone.0024580. PMC 3167858. PMID 21915353.
  17. ^ a b c d Pitcher, Tony (1986). The Behavior of Teleost Fishes. Baltimore: The Johns Hopkins University Press.
  18. ^ a b c d Manassa, R.P. (2013). "Coral reef fish incorporate multiple sources of visual and chemical information to mediate predation risk". Animal Behaviour. 86: 717–722. doi:10.1016/j.anbehav.2013.07.003.
  19. ^ a b c d e f Loke, Kerri (2011). "Reproductive Potential of the Protogynous Teleost, California Sheephead (Semicossyphus pulcher) at Nine Populations across Southern California". California Sea Grant College Program.
  20. ^ a b Hamilton, S. L., Caselle, J. E., Standish, J. D., Schroeder, D. M., Love, M. S., Rosales-Casian, J. A., & Sosa-Nishizaki, O. (2007). "Size-selective harvesting alters life histories of a temperate sex-changing fish". Ecological Applications. 17 (8): 2268–2280. doi:10.1890/06-1930.1.
  21. ^ a b c d e "Semicossyphus pulcher: California sheephead".
American cuisine

American cuisine reflects the history of the United States, blending the culinary contributions of various groups of people from around the world, including indigenous American Indians, African Americans, Asians, Europeans, Pacific Islanders, and South Americans. Early Native Americans utilized a number of cooking methods in early American Cuisine that have been blended with early European cooking methods to form the basis of American cuisine. The European settlement of the Americas yielded the introduction of a number of various ingredients, spices, herbs, and cooking styles to the latter. The various styles continued expanding well into the 19th and 20th centuries, proportional to the influx of immigrants from many different nations; this influx nurtured a rich diversity in food preparation throughout the country.

When the colonists came to the colonies, they farmed animals for clothing and meat in a similar fashion to what they had done in Europe. They had cuisine similar to their previous Dutch, Swedish, French and British cuisines. The American colonial diet varied depending on the settled region in which someone lived. Commonly hunted game included deer, bear, buffalo, and wild turkey. A number of fats and oils made from animals served to cook much of the colonial foods. Prior to the Revolution, New Englanders consumed large quantities of rum and beer, as maritime trade provided them relatively easy access to the goods needed to produce these items: rum was the distilled spirit of choice, as the main ingredient, molasses, was readily available from trade with the West Indies. In comparison to the northern colonies, the southern colonies were quite diverse in their agricultural diet. The growing season was longer.

During the 18th and 19th centuries, Americans developed many new foods. During the Progressive Era of the late 19th and early 20th centuries, c. 1890s–1920s, food production and presentation became more industrialized. One characteristic of American cooking is the fusion of multiple ethnic or regional approaches into completely new cooking styles. A wave of celebrity chefs began with Julia Child and Graham Kerr in the 1970s, with many more following after the rise of cable channels, such as the Food Network and Cooking Channel, in the late 20th century.

Benthos

Benthos is the community of organisms that live on, in, or near the seabed, also known as the benthic zone. This community lives in or near marine sedimentary environments, from tidal pools along the foreshore, out to the continental shelf, and then down to the abyssal depths.

Many organisms adapted to deep-water pressure cannot survive in the upper parts of the water column. The pressure difference can be very significant (approximately one atmosphere for each 10 metres of water depth).Because light is absorbed before it can reach deep ocean-water, the energy source for deep benthic ecosystems is often organic matter from higher up in the water column that drifts down to the depths. This dead and decaying matter sustains the benthic food chain; most organisms in the benthic zone are scavengers or detritivores.

The term benthos, coined by Haeckel in 1891, comes from the Greek noun βένθος "depth of the sea". Benthos is also used in freshwater biology to refer to organisms at the bottom of freshwater bodies of water, such as lakes, rivers, and streams. There is also a redundant synonym, benthon.

California spiny lobster

The California spiny lobster (Panulirus interruptus) is a species of spiny lobster found in the eastern Pacific Ocean from Monterey Bay, California to the Gulf of Tehuantepec, Mexico. It typically grows to a length of 30 cm (12 in) and is a reddish-brown color with stripes along the legs, and has a pair of enlarged antennae but no claws. The interrupted grooves across the tail are characteristic for the species.

Females can carry up to 680,000 eggs, which hatch after 10 weeks into flat phyllosoma larvae. These feed on plankton before the metamorphosis into the juvenile state. Adults are nocturnal and migratory, living among rocks at depths of up to 65 m (213 ft), and feeding on sea urchins, clams, mussels and worms. The spiny lobster is eaten by various fish, octopuses and sea otters, but can defend itself with a loud noise produced by its antennae. The California spiny lobster is the subject of both commercial and recreational fishery in both Mexico and the United States, with sport fishermen using hoop nets and commercial fishermen using lobster traps.

Fish

Fish are gill-bearing aquatic craniate animals that lack limbs with digits. They form a sister group to the tunicates, together forming the olfactores. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Tetrapods emerged within lobe-finned fishes, so cladistically they are fish as well. However, traditionally fish are rendered paraphyletic by excluding the tetrapods (i.e., the amphibians, reptiles, birds and mammals which all descended from within the same ancestry). Because in this manner the term "fish" is defined negatively as a paraphyletic group, it is not considered a formal taxonomic grouping in systematic biology, unless it is used in the cladistic sense, including tetrapods. The traditional term pisces (also ichthyes) is considered a typological, but not a phylogenetic classification.

The earliest organisms that can be classified as fish were soft-bodied chordates that first appeared during the Cambrian period. Although they lacked a true spine, they possessed notochords which allowed them to be more agile than their invertebrate counterparts. Fish would continue to evolve through the Paleozoic era, diversifying into a wide variety of forms. Many fish of the Paleozoic developed external armor that protected them from predators. The first fish with jaws appeared in the Silurian period, after which many (such as sharks) became formidable marine predators rather than just the prey of arthropods.

Most fish are ectothermic ("cold-blooded"), allowing their body temperatures to vary as ambient temperatures change, though some of the large active swimmers like white shark and tuna can hold a higher core temperature.Fish can communicate in their underwater environments through the use of acoustic communication. Acoustic communication in fish involves the transmission of acoustic signals from one individual of a species to another. The production of sounds as a means of communication among fish is most often used in the context of feeding, aggression or courtship behaviour. The sounds emitted by fish can vary depending on the species and stimulus involved. They can produce either stridulatory sounds by moving components of the skeletal system, or can produce non-stridulatory sounds by manipulating specialized organs such as the swimbladder.Fish are abundant in most bodies of water. They can be found in nearly all aquatic environments, from high mountain streams (e.g., char and gudgeon) to the abyssal and even hadal depths of the deepest oceans (e.g., gulpers and anglerfish), although no species has yet been documented in the deepest 25% of the ocean. With 33,600 described species, fish exhibit greater species diversity than any other group of vertebrates.Fish are an important resource for humans worldwide, especially as food. Commercial and subsistence fishers hunt fish in wild fisheries (see fishing) or farm them in ponds or in cages in the ocean (see aquaculture). They are also caught by recreational fishers, kept as pets, raised by fishkeepers, and exhibited in public aquaria. Fish have had a role in culture through the ages, serving as deities, religious symbols, and as the subjects of art, books and movies.

Haliotis cracherodii

Haliotis cracherodii (black abalone) is a species of large edible sea snail, a marine gastropod mollusk in the family Haliotidae, the abalones.This species is relatively small compared with most of the other abalone species from the eastern Pacific, and it has a relatively smooth dark shell.

This used to be the most abundant large marine mollusk on the west coast of North America, but now, because of overfishing and the Withering Syndrome, it has much declined in population and the IUCN Red List has classed the black abalone as Critically Endangered.

Harem (zoology)

A harem is an animal group consisting of one or two males, a number of females, and their offspring. The dominant male drives off other males and maintains the unity of the group. If present, the second male is subservient to the dominant male. As juvenile males grow, they leave the group and roam as solitary individuals or join bachelor herds. Females in the group may be inter-related. The dominant male mates with the females as they become sexually active and drives off competitors, until he is displaced by another male. In some species, incoming males that achieve dominant status may commit infanticide.

For the male, the main benefits of the harem system is obtaining exclusive access to a group of mature females. The females benefit from being in a stable social group and the associated benefits of grooming, predator avoidance and cooperative defense of territory. The disadvantages for the male are the energetic costs of gaining or defending a harem which may leave him with reduced reproductive success. The females are disadvantaged if their offspring are killed during dominance battles or by incoming males.

Kelp forest

Kelp forests are underwater areas with a high density of kelp. They are recognized as one of the most productive and dynamic ecosystems on Earth. Smaller areas of anchored kelp are called kelp beds.

Kelp forests occur worldwide throughout temperate and polar coastal oceans. In 2007, kelp forests were also discovered in tropical waters near Ecuador.Physically formed by brown macroalgae, kelp forests provide a unique, three-dimensional habitat for marine organisms and are a source for understanding many ecological processes. Over the last century, they have been the focus of extensive research, particularly in trophic ecology, and continue to provoke important ideas that are relevant beyond this unique ecosystem. For example, kelp forests can influence coastal oceanographic patterns and provide many ecosystem services.However, the influence of humans has often contributed to kelp forest degradation. Of particular concern are the effects of overfishing nearshore ecosystems, which can release herbivores from their normal population regulation and result in the overgrazing of kelp and other algae. This can rapidly result in transitions to barren landscapes where relatively few species persist. The implementation of marine protected areas is one management strategy useful for addressing such issues, since it may limit the impacts of fishing and buffer the ecosystem from additive effects of other environmental stressors.

List of fish named after animals

This is a list of fish with common names that are based on the names of other animals. The names listed here may refer to single species, broader taxa (genera, families), or assortments of types. Where names are ambiguous, the various meanings should be listed here.

List of vulnerable fishes

As of September 2016, the International Union for Conservation of Nature (IUCN) lists 1245 vulnerable fish species. 8.1% of all evaluated fish species are listed as vulnerable.

The IUCN also lists eight fish subspecies as vulnerable.

Of the subpopulations of fishes evaluated by the IUCN, 18 species subpopulations have been assessed as vulnerable.

For a species to be assessed as vulnerable to extinction the best available evidence must meet quantitative criteria set by the IUCN designed to reflect "a high risk of extinction in the wild". Endangered and critically endangered species also meet the quantitative criteria of vulnerable species, and are listed separately. See: List of endangered fishes, List of critically endangered fishes. Vulnerable, endangered and critically endangered species are collectively referred to as threatened species by the IUCN.

Additionally 3191 fish species (21% of those evaluated) are listed as data deficient, meaning there is insufficient information for a full assessment of conservation status. As these species typically have small distributions and/or populations, they are intrinsically likely to be threatened, according to the IUCN. While the category of data deficient indicates that no assessment of extinction risk has been made for the taxa, the IUCN notes that it may be appropriate to give them "the same degree of attention as threatened taxa, at least until their status can be assessed."This is a complete list of vulnerable fish species and subspecies evaluated by the IUCN. Species and subspecies which have vulnerable subpopulations (or stocks) are indicated.

Maritime history of California

In the California coast, the use of ships and the Pacific Ocean has historically included water craft (such as dugouts, canoes, sailing ships, and steamships), fisheries, shipbuilding, Gold Rush shipping, ports, shipwrecks, naval ships and installations, and lighthouses. The maritime history of California can be divided into several periods: the Native American period; European exploration period from 1542 to 1769; the Spanish colonial period, 1769 to 1821; the Mexican period, 1821 to 1847; and United States statehood period, which continues to the present day.

Pagurus samuelis

Pagurus samuelis, the blueband hermit crab, is a species of hermit crab from the west coast of North America, and the most common hermit crab in California. It is a small species, with distinctive blue bands on its legs. It prefers to live in the shell of the black turban snail, and is a nocturnal scavenger of algae and carrion.

Santa Catalina Island (California)

Santa Catalina Island (Tongva: Pimugna or Pimu) is a rocky island off the coast of the U.S. state of California in the Gulf of Santa Catalina. The island name is often shortened to Catalina Island or just Catalina. The island is 22 mi (35 km) long and 8 mi (13 km) across at its greatest width. The island is located about 29 mi (47 km) south-southwest of Long Beach, California. The highest point on the island is 2,097 ft (639 m) atop Mount Orizaba. Santa Catalina is part of the Channel Islands of California archipelago and lies within Los Angeles County.

Catalina was originally settled by Native Americans who called the island Pimugna or Pimu and referred to themselves as Pimugnans or Pimuvit. The first Europeans to arrive on Catalina claimed it for the Spanish Empire. Over the years, territorial claims to the island transferred to Mexico and then to the United States. During this time, the island was sporadically used for smuggling, otter hunting, and gold-digging, before successfully being developed into a tourist destination by chewing gum magnate William Wrigley, Jr. beginning in the 1920s. Since the 1970s, most of the island has been administered by the Catalina Island Conservancy.

Its total population in the 2010 census was 4,096 people, 90 percent of whom live in the island's only incorporated city, Avalon. The second center of population is the unincorporated village of Two Harbors at the island's isthmus. Development occurs also at the smaller settlements of Rancho Escondido and Middle Ranch. The remaining population is scattered over the island between the two population centers.

Sea urchin

Sea urchins or urchins () are typically spiny, globular animals, echinoderms in the class Echinoidea. About 950 species live on the seabed, inhabiting all oceans and depth zones from the intertidal to 5,000 metres (16,000 ft; 2,700 fathoms). Their tests (hard shells) are round and spiny, typically from 3 to 10 cm (1 to 4 in) across. Sea urchins move slowly, crawling with their tube feet, and sometimes pushing themselves with their spines. They feed primarily on algae but also eat slow-moving or sessile animals. Their predators include sea otters, starfish, wolf eels, and triggerfish.

Like other echinoderms, urchins have fivefold symmetry as adults, but their pluteus larvae have bilateral (mirror) symmetry, indicating that they belong to the Bilateria, the large group of animal phyla that includes chordates, arthropods, annelids and molluscs. They are widely distributed across all the oceans, all climates from tropical to polar, and inhabit marine benthic (sea bed) habitats from rocky shores to hadal zone depths. Echinoids have a rich fossil record dating back to the Ordovician, some 450 million years ago. Their closest relatives among the echinoderms are the sea cucumbers (Holothuroidea); both are deuterostomes, a clade which includes the chordates.

The animals have been studied since the 19th century as model organisms in developmental biology, as their embryos were easy to observe; this has continued with studies of their genomes because of their unusual fivefold symmetry and relationship to chordates. Species such as the slate pencil urchin are popular in aquariums, where they are useful for controlling algae. Fossil urchins have been used as protective amulets.

Semicossyphus

Semicossyphus is a genus of wrasses native to the Pacific Ocean.

Sequential hermaphroditism

Sequential hermaphroditism (called dichogamy in botany) is a type of hermaphroditism that occurs in many fish, gastropods, and plants. Sequential hermaphroditism occurs when the individual changes sex at some point in its life.

In animals, the different types of change are male to female (protandry), female to male (protogyny), female to hermaphrodite (protogynous hermaphroditism), and male to hermaphrodite (protandrous hermaphroditism). Those that change gonadal sex can have both female and male germ cells in the gonads or can change from one complete gonadal type to the other during their last life stage.In plants, individual flowers are called dichogamous if their function has the two sexes separated in time, although the plant as a whole may have functionally male and functionally female flowers open at any one moment. A flower is protogynous if its function is first female, then male, and protandrous if its function is male then female. It used to be thought that this reduced inbreeding, but it may be a more general mechanism for reducing pollen-pistil interference.

Sheepshead porgy

The sheepshead porgy (Calamus penna) is a species of fish of the porgy family, Sparidae, only found in the Atlantic Ocean. It is only distantly related to the California sheephead of the Pacific Ocean.

Sheepshead Bay in Brooklyn is named after this fish.

Wrasse

The wrasses are a family, Labridae, of marine fish, many of which are brightly colored. The family is large and diverse, with over 600 species in 81 genera, which are divided into 9 subgroups or tribes.

They are typically small fish, most of them less than 20 cm (7.9 in) long, although the largest, the humphead wrasse, can measure up to 2.5 m (8.2 ft). They are efficient carnivores, feeding on a wide range of small invertebrates. Many smaller wrasses follow the feeding trails of larger fish, picking up invertebrates disturbed by their passing. Juveniles of some representatives of the genera Bodianus, Epibulus, Cirrhilabrus, Oxycheilinus, and Paracheilinus hide among the tentacles of the free-living mushroom coral Heliofungia actiniformis.The word "wrasse" comes from the Cornish word wragh, a lenited form of gwragh, meaning an old woman or hag, via Cornish dialect wrath. It is related to the Welsh gwrach and Breton gwrac'h.

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