Black gill disease

Last updated

Black gill disease, also known as black spot disease or black death, is a disease affecting various species of marine animals, including shellfish and crustaceans, across the Atlantic and Pacific oceans. The disease is characterized by the visibly noticeable black melanated gills, speculated to be caused by a fungus called Fusarium solani or a similarly shaped ciliate. Human consumption of fish affected by black gill disease is harmless. [1]

Contents

A significant portion of the aquaculture communities and fishing businesses have scientifically observed a steady decline in healthy fish capture since 1996, [1] contributing to a shortage [2] of shrimp and fish in the food industry. The origin of the fungus agent causing black gill disease is unknown [3] and unlikely to dissipate. Researchers have also observed a causal relationship between the disease and environmental factors, such as waste spill [3] contamination, ocean pollution, and climate change. [4]

Studies to determine the prevalence of the disease have been largely conducted by methodically collecting batches of healthy and infected shrimp across regional coastlines. Two main species of shrimp used for research include Litopenaeus setiferus (white shrimp) and Farfantepenaeus aztecus (brown shrimp).

Characteristics

A circular fungus attaches itself to gill nodules in shrimp. Ciliate collage.jpg
A circular fungus attaches itself to gill nodules in shrimp.

Black gill disease is visible to the human eye. Affected gills may exhibit crusted, surface-corroding,[ citation needed ] scattered light brown to black spots or a large black patch on one or both sides of the fish. [3] Discoloration at the gill area will be distinct from the rest of the body. These symptoms are separate from gill fouling or fin rot. [3]

Normal colored shrimp do not necessarily mean a lack of infection. Scientists have microscopically observed the ciliate in shrimp that had not reached the discoloration phase. Seen under an electron microscope, the foreign circular ciliates (30–38 μm) attach to the gill nodules, creating cystic imprints on the tissue. [3] More rarely, the ciliate may penetrate the tissue and house invasively. [3]

The fungus is potentially contagious. Upon capture, an infected head placed near an entirely healthy animal can infect the latter. [5]

Causes

Many potential pathogens can cause black gill, including bacteria, viruses, fungi, and ciliates. [6] Abiotic stress, such as injury and foreign bodies, can also activate a crustacean's immune system and result in melanin production and black gill symptoms. [6]

Research in the Persian Gulf,[ citation needed ] China, [7] and India has resulted in an initial determination that a fungus exactly or related to Fusarium solani is responsible for black gill disease.

The ciliate attacks fish respiration processes. Fish Respiration Through Gills.svg
The ciliate attacks fish respiration processes.

Extensive research ongoing since 2010 [8] and funded by the University of Georgia has determined that an invasive ciliate strain, possibly Hyalophysa chattoni, attaches itself to gill nodules. The presumed ciliate propagates while activating oxygenation of phenols within the organic makeup of the sea creature. This oxygenation process results in melanin, leading to the visible black tissue. But most importantly, the ciliate impairs and blocks necessary respiratory processes and hemolymph flows for ion regulation. [2] The diseased gills inhibit the entire immune system, leading to early natural death or inability to evade other ocean predators. [5]

Metal contamination originating from industrial waste, oil spills, and general water pollution has been reported as a contributing factor to the black gill disease epidemic seen in crustaceans. [3] A direct correlation has not been confirmed.

Environmental and climate changes affecting temperature and salt water content have been confirmed sources of parasite families, including ciliates. In a controlled environment, it is possible to prevent cases of black gill disease. The water should have 10-20 parts per thousand parts salinity and filtered. [9] Scientists have reviewed ocean lifeforms in reference to possible effects of Pacifical Decadal Oscillation and El Niño climate occurrences, concluding the patterned emergence of black gill disease is linked to large-scale weather events. [2]

Affected regions

Black gill disease is confirmed in fish, crabs, and shrimp at human populated coastlines across four continents. Each region's scientists conducted histological study of shrimp control and diseased groups. The results present the universality of black gill disease across all water bodies.

Asia

North America

Australia

Other impacts

The seafood industry based out of the Carolinas and Georgia experienced a decline in shrimp capture beginning from 1996, generating half the revenue by 2014 at $5.5 million. [8]

University of Georgia's research for the cause of black gill disease in the U.S. Southeast coast led to the first-time sequencing of rRNA (18S rRNA) gene (1634 bp) from the suspected Hyalophysa chattoni ciliate related strain. The sequence has been recorded in the National Center for Biotechnology Information Genbank database. [3]

Related Research Articles

<span class="mw-page-title-main">Shellfish</span> Culinary and fisheries term for exoskeleton-bearing aquatic invertebrates

Shellfish is a colloquial and fisheries term for exoskeleton-bearing aquatic invertebrates used as food, including various species of molluscs, crustaceans, and echinoderms. Although most kinds of shellfish are harvested from saltwater environments, some are found in freshwater. In addition, a few species of land crabs are eaten, for example Cardisoma guanhumi in the Caribbean. Shellfish are among the most common food allergens.

<span class="mw-page-title-main">Selective breeding</span> Breeding for desired characteristics

Selective breeding is the process by which humans use animal breeding and plant breeding to selectively develop particular phenotypic traits (characteristics) by choosing which typically animal or plant males and females will sexually reproduce and have offspring together. Domesticated animals are known as breeds, normally bred by a professional breeder, while domesticated plants are known as varieties, cultigens, cultivars, or breeds. Two purebred animals of different breeds produce a crossbreed, and crossbred plants are called hybrids. Flowers, vegetables and fruit-trees may be bred by amateurs and commercial or non-commercial professionals: major crops are usually the provenance of the professionals.

<span class="mw-page-title-main">Fishery</span> Raising or harvesting fish

Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life or, more commonly, the site where such enterprise takes place. Commercial fisheries include wild fisheries and fish farms, both in freshwater waterbodies and the oceans. About 500 million people worldwide are economically dependent on fisheries. 171 million tonnes of fish were produced in 2016, but overfishing is an increasing problem, causing declines in some populations.

<i>Ichthyophthirius multifiliis</i> Parasitic species of protozoan

Ichthyophthirius multifiliis, often termed "Ich", is a parasitic ciliate described by the French parasitologist Fouquet in 1876. Only one species is found in the genus which also gave name to the family. The name literally translates as "the fish louse with many children". The parasite can infect most freshwater fish species and, in contrast to many other parasites, shows low host specificity. It penetrates gill epithelia, skin and fins of the fish host and resides as a feeding stage inside the epidermis. It is visible as a white spot on the surface of the fish but, due to its internal microhabitat, it is a true endoparasite and not an ectoparasite.

<span class="mw-page-title-main">Marine shrimp farming</span> Aquaculture of shrimp or prawns

Marine shrimp farming is an aquaculture business for the cultivation of marine shrimp or prawns for human consumption. Although traditional shrimp farming has been carried out in Asia for centuries, large-scale commercial shrimp farming began in the 1970s, and production grew steeply, particularly to match the market demands of the United States, Japan and Western Europe. The total global production of farmed shrimp reached more than 1.6 million tonnes in 2003, representing a value of nearly 9 billion U.S. dollars. About 75% of farmed shrimp is produced in Asia, in particular in China and Thailand. The other 25% is produced mainly in Latin America, where Brazil, Ecuador, and Mexico are the largest producers. The largest exporting nation is India.

White spot syndrome (WSS) is a viral infection of penaeid shrimp. The disease is highly lethal and contagious, killing shrimp quickly. Outbreaks of this disease have wiped out the entire populations of many shrimp farms within a few days, in places throughout the world.

Taura syndrome (TS) is one of the more devastating diseases affecting the shrimp farming industry worldwide. It was first described in Ecuador during the summer of 1992. In March 1993, it returned as a major epidemic and was the object of extensive media coverage. Retrospective studies have suggested a case of Taura syndrome might have occurred on a shrimp farm in Colombia as early as 1990 and the virus was already present in Ecuador in mid-1991. Between 1992 and 1997, the disease spread to all major regions of the Americas where whiteleg shrimp is cultured. The economic impact of TS in the Americas during that period might have exceeded US$2 billion by some estimates.

<span class="mw-page-title-main">Shrimp farming</span>

Shrimp farming is an aquaculture business that exists in either a marine or freshwater environment, producing shrimp or prawns for human consumption.

Necrotising hepatopancreatitis (NHP), is also known as Texas necrotizing hepatopancreatitis (TNHP), Texas pond mortality syndrome (TPMS) and Peru necrotizing hepatopancreatitis (PNHP), is a lethal epizootic disease of farmed shrimp. It is not very well researched yet, but generally assumed to be caused by a bacterial infection.

<i>Penaeus monodon</i> Species of crustacean

Penaeus monodon, commonly known as the giant tiger prawn, Asian tiger shrimp, black tiger shrimp, and other names, is a marine crustacean that is widely reared for food.

<i>Cryptocaryon</i> Genus of single-celled organisms

Cryptocaryon irritans is a species of ciliates that parasitizes marine fish, causing marine white spot disease or marine ich. It is one of the most common causes of disease in marine aquaria.

<i>Gibberella zeae</i> Species of fungus

Gibberella zeae, also known by the name of its anamorph Fusarium graminearum, is a fungal plant pathogen which causes fusarium head blight (FHB), a devastating disease on wheat and barley. The pathogen is responsible for billions of dollars in economic losses worldwide each year. Infection causes shifts in the amino acid composition of wheat, resulting in shriveled kernels and contaminating the remaining grain with mycotoxins, mainly deoxynivalenol (DON), which inhibits protein biosynthesis; and zearalenone, an estrogenic mycotoxin. These toxins cause vomiting, liver damage, and reproductive defects in livestock, and are harmful to humans through contaminated food. Despite great efforts to find resistance genes against F. graminearum, no completely resistant variety is currently available. Research on the biology of F. graminearum is directed towards gaining insight into more details about the infection process and reveal weak spots in the life cycle of this pathogen to develop fungicides that can protect wheat from scab infection.

<i>Palaemon serratus</i> Species of crustacean

Palaemon serratus, also called the common prawn, is a species of shrimp found in the Atlantic Ocean from Denmark to Mauritania, and in the Mediterranean Sea and Black Sea.

Hematodinium is a genus of dinoflagellates. Species in this genus, such as Hematodinium perezi, the type species, are internal parasites of the hemolymph of crustaceans such as the Atlantic blue crab and Norway lobster. Species in the genus are economically damaging to commercial crab fisheries, including causing bitter crab disease in the large Tanner or snow crab fisheries of the Bering Sea.

<span class="mw-page-title-main">Aquaculture in South Korea</span>

South Korea is a major center of aquaculture production, and the world's third largest producer of farmed algae as of 2020.

Scuticociliatosis is a severe and often fatal parasitic infection of several groups of marine organisms. Species known to be susceptible include a broad range of teleosts, seahorses, sharks, and some crustaceans. The disease can be caused by any one of about 20 distinct species of unicellular eukaryotes known as scuticociliates, which are free-living marine microorganisms that are opportunistic or facultative parasites. Scuticociliatosis has been described in the wild, in captive animals in aquariums, and in aquaculture. It is best studied in fish species that are commonly farmed, in which typical effects of infection include skin ulceration, hemorrhage, and necrosis, with post-mortem examination identifying ciliates in the skin, gills, blood, and internal organs including the brain.

Nematopsis (Nee-mah-top-cis) is a genus gregarine Apicomplexan of the family Porosporidae. It is an aquatic parasite of crustaceans with a molluscan intermediate host. Nematopsis has been distinguished from the similar genus Porospora by its resistant and encapsulated oocyst. Little molecular biology has been performed on the members of the Nemaptosis and species are described based on molluscan and crustacean hosts as well as oocyst structure. A total of 38 species have been described and are found all over the world.

<span class="mw-page-title-main">Black pomfret</span> Species of fish

The black pomfret is a species of carangid native to reefs of the Indian Ocean and western Pacific Ocean. This species is very important to local fisheries and is the only known member of its genus.

Hepatopancreatic parvovirus (HPV) is a group of viruses in the family Parvoviridae with single-stranded DNA containing genomes that infects shrimp, prawn and other crustacean populations. HPV infects the epithelial cells of the host's hepatopancreas and midgut, leading to the stunted growth at the early life stage. For shrimp farms, especially in Asian countries such as China, India and Indonesia, HPV can lead to economic losses in aquaculture due to the reduced production.

References

  1. 1 2 Landers, Mary (27 June 2016). "Black gill disease shows up early in Georgia shrimp". The Florida Times-Union.
  2. 1 2 3 Kendrick, Michael R.; Brunson, Jeff F.; Frischer, Marc E.; Kingsley-Smith, Peter R. (May 2021). "Climate Indices Predict Black Gill Prevalence in White Shrimp Penaeus setiferus (Linnaeus, 1767) in South Carolina and Georgia, USA". Journal of Shellfish Research. 40 (1): 145–151. doi:10.2983/035.040.0114. ISSN   0730-8000. S2CID   233485855.
  3. 1 2 3 4 5 6 7 8 9 Frischer, Marc E.; Lee, Richard F.; Price, Ashleigh R.; Walters, Tina L.; Bassette, Molly A.; Verdiyev, Rufat; Torris, Michael C.; Bulski, Karrie; Geer, Patrick J.; Powell, Shirley A.; Walker, Anna N.; Landers, Stephen C. (August 2017). "Causes, Diagnostics, and Distribution of an Ongoing Penaeid Shrimp Black Gill Epidemic in the U.S. South Atlantic Bight". Journal of Shellfish Research. 36 (2): 487–500. doi: 10.2983/035.036.0220 . ISSN   0730-8000. S2CID   90959506.
  4. Landers, Mary (14 September 2021). "Research connects black gill in shrimp to warming climate". The Current.
  5. 1 2 Towers, Lucy (12 November 2013). "Black Gill Disease Blamed for Poor Shrimp Crop". thefishsite.com.
  6. 1 2 Frischer, Marc E.; Landers, Stephen C.; Walker, Anna N.; Powell, Shirley A.; Lee, Richard F. (2 October 2022). "Black Gill in Marine Decapod Crustaceans: A Review". Reviews in Fisheries Science & Aquaculture. 30 (4): 498–519. Bibcode:2022RvFSA..30..498F. doi: 10.1080/23308249.2022.2047153 . ISSN   2330-8249.
  7. 1 2 3 Yao, Liang-Fei; Wang, Chong; Li, Ge; Xie, G.; Jia, Yan-zhe; Wang, Wei; Liu, Shuang; Xu, Tingting; Luo, Kun; Zhang, Qing-Li; Kong, J. (2021). "Identification of Fusarium solani as a causal agent of black spot disease (BSD) of Pacific white shrimp, Litopenaeus vannamei". Aquaculture. 548: 737602. doi:10.1016/j.aquaculture.2021.737602. S2CID   244584630.
  8. 1 2 Marine Extension and Georgia Sea Grant, University of Georgia. "Black Gill". UGA Marine Extension and Georgia Sea Grant. Retrieved 5 October 2022.
  9. ASEAN (1978). "Manuel on Pond Culture of Penaeid Shrimp". FAO Corporate Document Repository. Association of Southeast Asian Nations. Retrieved 28 April 2016.