Cynoscion parvipinnis

Geographic Range

Shortfin corvina ( Cynoscion parvipinnis ) are found in the Eastern Pacific Ocean, from Southern California to Mazatlan, Mexico (34°N - 21°N, 118°W - 108°W). Although it is north of their usual range, they are known to use San Diego Bay as a warm water refuge.

• Biogeographic Regions
• nearctic nearctic
  • native native
• pacific ocean pacific ocean
  • native native

Habitat

Shortfin corvinas are demersal, living and feeding near the sandy or gravelly bottoms of shallow coastal (inshore) waters, although they can be found at depths up to 100 meters. Individuals found north of Point Banda, Mexico are most common in protected bays and estuaries and is also found in mangrove forests. This species is often associated with beds of eelgrass ( Zostera marina ) and river mouths.

• Habitat Regions
• temperate temperate
• tropical tropical
• saltwater or marine saltwater or marine

• Aquatic Biomes
• pelagic pelagic
• coastal coastal
• brackish water brackish water

• Other Habitat Features
• estuarine estuarine
• intertidal or littoral intertidal or littoral

Physical Description

Body coloration is gray to blue on the dorsal surface fading to silver to white sides with a pale ventral surface, while the area at the base of pectoral fin is darker than the body. The color of the interior of the mouth ranges from pale yellow to orange. The dorsal fin consists of 8 to 11 spiny rays and 21 to 24 soft rays. The anal fin has 2 spiny rays and 10 to 11 soft rays; the caudal fin is concave; lower jaw protruding, extending beyond upper jaw; upper jaw originating behind posterior margin of eye; 1 to 2 prominent canines on upper jaw; multiple tooth rows; chin without barbel or distinct pores; (9) 10 to 12 gill rakers with (8) 7 to 9 on lower limb of first arch; pelvic fins extending well beyond tips of short pectoral fins; interior of operculum dark; arch in lateral line above pectoral fin. Cynoscion parvipinnis is distinguished from juvenile specimens of Atractoscion nobilis by the absence of raised ridge along ventral surface in the former.

• Other Physical Features
• ectothermic ectothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• sexes alike

Development

• Development - Life Cycle
• indeterminate growth indeterminate growth

Reproduction

This species is a pelagic broadcast spawner.

• Mating System
• polygynandrous (promiscuous) polygynandrous (promiscuous)

Other members of the genus Cynoscion have been observed to produce audible vibrations by contracting muscles around the swim bladder (“croaking”) during mating season, presumably to alert potential mates to their presence. This behavior has yet to be formally documented in C. parvipinnis . Breeding interval is unknown; most likely once per breeding season. Spawning has been documented in Mexican populations in late April.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• fertilization fertilization
  • external external
• broadcast (group) spawning
• oviparous oviparous

As this species is a broadcast spawner, there is no parental care for offspring.

• Parental Investment
• no parental involvement

Lifespan/Longevity

Behavior

Most active at night, with peak activity occurring at sunrise and sunset in shallow water areas. During the day, the shortfin corvina tends to remain around cover such as deeper water; shaded areas around docks, piers and bridges; or channels in rocky areas. Individuals become increasingly solitary with age, forming temporary age-segregated schools of less than a dozen members.

• Key Behaviors
• natatorial natatorial
• crepuscular crepuscular
• motile motile
• migratory migratory

Home Range

This species does not defend a territory nor does it occupy a home range.

Communication and Perception

As with other members of the family Sciaenidae , C. parvipinnis is anatomically capable of producing a “croaking” sound via the rapid and repeated contraction of muscles against the swim bladder. The shortfin corvina makes use of its lateral line, and well-developed eyes which are sensitive to, and highly perceptive of changes in ambient light levels to immediately locate its prey. Its olfactory sense detects potential prey located outside the range of its previous two senses.

• Communication Channels
• acoustic acoustic
• chemical chemical

• Other Communication Modes
• pheromones pheromones
• vibrations vibrations

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• vibrations vibrations
• chemical chemical

Food Habits

Shortfin corvina larvae feed upon copepods, amphipods, and other planktonic organisms, becoming increasingly piscivorous with age. Adults are opportunistic carnivores, feeding primarily on crustaceans and other fish at trophic level 2.8 and above. Important forage fishes include anchovies and silversides Anchoa and Atherinops , the “CIQ Complex Gobies” ( Clevelandia ios , Ilypnus gilbert , and Quietula y-cauda ) of the family Gobiidae (a primary food source for juvenile shortfin corvina); the California killifish ( Fundulus parvipinnis ), and viviparous perches of the family Embiotocidae . The California grunion ( Leuresthes tenuis ) is particularly important, and C. parvipinnis has been observed aggressively feeding upon them in shallow water during the grunion’s bimonthly summer spawning events. Shortfin corvina have been observed to repeatedly jump out of the water in pursuit of prey at dawn and dusk. Groups of up to 4 individuals have been seen driving schools of forage fish to the surface before breaking the surface of the water in what may represent a form of cooperative hunting effort. The enlarged canine teeth aid in the capture and subdual of larger forage fish.

• Primary Diet
• carnivore carnivore
  • piscivore piscivore
  • eats non-insect arthropods
  • molluscivore molluscivore
• planktivore planktivore

• Animal Foods
• fish
• mollusks
• aquatic or marine worms
• aquatic crustaceans
• echinoderms
• other marine invertebrates
• zooplankton zooplankton

Predation

Pinnipeds in the families Phocidae and Otariidae are the most common predators of adult fish in protected bays. Due to their relatively large size, the only other predators of adult shortfin corvina are large sharks and groupers, with the giant sea bass ( Stereolepis gigas ), soupfin shark ( Galeorhinus galeus ) and broadnose sevengill shark ( Notorynchus cepedianus ) most prominent in the northern part of their range. In the southern range of C. parvipinnis , hammerhead sharks ( Sphyrna spp.), the tiger shark ( Galeocerdo cuvier ), and various other Carcharhiniform sharks become prominent, in addition to several groupers in the genus Mycteroperca .

The shortfin corvina utilizes countershading as a means of camouflage against potential predators. Juveniles may aggregate in beds of the eelgrass Zostera marina for protection.

• Anti-predator Adaptations
• cryptic cryptic

Ecosystem Roles

The primary impact of Cynoscion parvipinnis upon their ecosystem is via their predation on other fish species. In brackish water environments, the shortfin corvina directly competes with avian species for forage fishes in the families Atherinopsidae , Engraulidae , and Embiotocidae , as well as the California killifish ( Fundulus parvipinnis ), and the California halfbeak ( Hyporhamphus rosae ). This provides an interesting example of the way that two organisms need not be aware of the others’ existence to compete in the same ecosystem.

Economic Importance for Humans: Positive

Cynoscion parvipinnis is an important gamefish throughout its range. In Mexico it is the target of a commercial fishery and is sold both locally and in the United States, where it is uncommonly caught as bycatch.

• Positive Impacts
• food food

Economic Importance for Humans: Negative

There are no known negative effects of Cynoscion parvipinnis on humans.

Conservation Status

As of 2012, the IUCN lists Cynoscion parvipinnis as declining in population within its range.

Additional Links

Encyclopedia of Life

Contributors

Aaron Lerer (author), San Diego Mesa College, Paul Detwiler (editor), San Diego Mesa College, Jeremy Wright (editor), University of Michigan-Ann Arbor.

References

Agbayani, E., C. Elloran, K. Banasihan. 2011. "Length-Weight Relationship for Cynoscion parvipinnis " (On-line). FishBase. Accessed October 10, 2012 at http://www.fishbase.us/PopDyn/FishLWSummary.php?ID=3581&id2=5657&Genus=Cynoscion&Species=parvipinnis&variable_Length=28&variable_Length_required=Edit+box+can+not+be+blank. .

Anònim, 1994. Atlas Pesquero de México . Mexico: Instituto Nacional de la Pesca.

Cannon, R. 1953. How to Fish the Pacific Coast . Menlo Park, California: Lane Publishing Company.

Chao, L., H. Espinosa, L. Findley, A. van der Heiden. 2012. "Cynoscion parvipinnis" (On-line). IUCN Red List of Threatened Species. Accessed November 01, 2012 at www.iucnredlist.org .

Fischer, W., F. Krupp, W. Schneider, C. Sommer, K. Carpenter, V. Niem, L. Chao. 1995. Guía FAO para la Identificación de Especies para los Fines de la Pesca Pacífico centro-oriental Volumen III. Vertebrados - Parte 2 . Roma: Organización de las Naciones Unidas para la Agricultura y la Alimentación.

Froese, R., P. Béarez. 2012. " Cynoscion parvipinnis , Shortfin weakfish" (On-line). Accessed September 20, 2012 at http://www.fishbase.us/summary/Cynoscion-parvipinnis.html .

International Gamefish Association, 2001. "Database of IGFA Angling Records until 2001" (On-line). Accessed September 20, 2012 at http://www.igfa.org/ .

Pondella, D., J. Williams. 2008. "Fisheries Inventory and Utilization of San Diego Bay, San Diego, California for Surveys Conducted in April and July 2008" (On-line pdf). Unified Port of San Diego. Accessed October 10, 2012 at http://www.portofsandiego.org/public-documents/doc_download/1902-2008-bay-wide-fish-survey.html .

Pondella, D., J. Williams. 2009. "Fisheries Inventory and Utilization of San Diego Bay, San Diego, California for Surveys Conducted in June 2009" (On-line pdf). Unified Port of San Diego. Accessed October 10, 2012 at http://www.portofsandiego.org/public-documents/doc_download/2069-vrg-fish-report-2009.html .

Tenera Environmental, 2004. "SBPP Cooling Water System Effects on San Diego Bay, Volume II: Compliance with Section 316(b) of the Clean Water Act for the South Bay Power Plant" (On-line). Accessed September 22, 2012 at http://swrcb2.swrcb.ca.gov/sandiego/board_decisions/adopted_orders/2004/2004_0154techrptb.pdf .

2012. "Cynoscion parvipinnis" (On-line). Encyclopedia of Life. Accessed February 04, 2013 at http://eol.org/pages/1012533/overview .

California Department of Fish and Game. Final California Commercial Landings for 2010. Sacramento, California: California Department of Fish and Game. 2011. Accessed November 24, 2012 at http://www.dfg.ca.gov/marine/landings10.asp .