The masked hamlet (Hypoplectrus providencianus) is a species of marine ray-finned fish, a sea bass from the subfamily Serraninae which is part of the family Serranidae, which also includes the groupers and anthias.[2] This species is found in the western Atlantic Ocean in the Caribbean Sea and has been recorded from the coast of Central America from Quintana Roo in Mexico to Bocas del Toro in Panama and from Jamaica to Puerto Rico, as well as in the Turks and Caicos and the Cayman Islands.[1] Its specific name refers to Providencia Island, Colombia where the type was collected.[3] It was also recorded from other islands in the Archipelago of San Andrés, Providencia and Santa Catalina.[3] They are a unique species in the Hypoplectrus genus, defined by their unique color morph.[4] Their behavior is largely similar to that of other hamlets, especially in their diet and egg-trading spawning patterns.[4][5]

Masked hamlet
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Perciformes
Family: Serranidae
Subfamily: Serraninae
Genus: Hypoplectrus
Species:
H. providencianus
Binomial name
Hypoplectrus providencianus

Anatomy and morphology edit

 
Masked hamlets have pale bodies with black, blue, and pale yellow fins and are identifiable by the black bar across their eyes.

H. providencianus can reach lengths of up to 13 cm.[6] This species' body plan is similar to that of unicolor hamlets.[7] H. providencianus possesses a spine at the base of the dorsal fin, a protruding upper jaw, a flattened head, and a lateral line running down the flank.[8]

Presumed to be unique to H. providencianus is a streak of black that surrounds the eye.[7] In addition to this, black coloration is present in most areas of the pectoral fins, being accented around the upper edges of the fin.[7] The caudal fin is also black, with a darker shade of black being present in the upper and lower lobes of the fin.[7] Also, a black caudal saddle may be present, or completely absent entirely.[7] The body is white in areas lacking black pigmentation.[7] Also, in comparison to other hamlets, H. providencianus lacks spots on the rostrum.[6]

Due to the similarities between the morphology of H. providencianus in comparison to that of its relatives, it is a difficult to classify the various species of the Hypoplectrus genus.[4] It is believed that H. providencianus is a color morph of the genus Hypoplectrus.[6]

Distribution and habitat edit

H. providencianus resides in coastal waters of the Caribbean, including near Mexico, Panama, Jamaica, Puerto Rico, Turks and Caicos, the Cayman Islands, Colombia, and the Archipelago of San Andrés, Providencia and Santa Catalina.[7] H. providencianus commonly makes its habitat in patch corals inside lagoons in relatively shallow waters of depths of about three to ten meters below sea level.[7] While the species may be present in the offshore waters of islands, they are the only member of the Hypoplectrus genus that is completely absent from continental shelves.[7] In addition, there is a lack of specific areas where H. providencianus congregate.[9] The masked hamlet tends to swim in lower sections of the water column near its habitat.[7]

In terms of diet, H. providencianus feeds on crustaceans and other small fish, much like the diets of other species in the Hypoplectrus genus.[4]

Behavior edit

Hamlets, as a genus, are generally territorial and eat invertebrates by gleaning (plucking them off from structures).[5] Each species in the genus generally exhibits the same feeding behaviors, except for the H. indigo which mostly eats Chromis cyaneus.[5]

This species lives a primarily solitary life and interacts with others during mating periods.[7]

Hamlets, including H. providencianus, are simultaneous hermaphrodites, which means they can produce both sperm and eggs at the same time, and each individual can play the role of male or female.[4] They egg trade which is the process of switching gender roles during a spawning session while exchanging gametes.[4] They spawn multiple times during each session.[4] It is unknown exactly how frequently they switch off roles, but in Hypoplectrus sp., it has been hypothesized that each individual swaps their gender role after each successive spawn, one releasing sperm and the other releasing eggs.[4] They broadcast spawn, which means they release the gametes into the water.[4] To figure out when to release their gametes, they use sounds to communicate with their partner.[4] Hamlets are able to colonize new areas because their pelagic larvae move throughout the water column.[8] Hamlets spawn at dusk.[10] There are a few hypotheses as to why this is, including that it limits predation on the embryos and that UV light from the sun cannot harm the embryos at the surface at night.[10]

Hamlets are able to hybridize and mate with other species of hamlets, but this is very rare.[4] They prefer to mate with fish of the same color morphs; however, they will mate with individuals of other hamlet species if it is their only option.[4] Hamlets mate with the same partner for multiple years in a row.[4]

Taxonomy edit

Hypoplectrus providencianus is one of the 17 currently defined species of hamlets (genus Hypoplectrus) and was identified by Acero P. and Garzón-Ferreira in 1994.[7]

Each species of hamlet is distinguished by its unique color pattern.[4] H. unicolor was originally placed in the genus Perca. H. puella, H. chlorurus, and H. unicolor were reclassified into the genus Plectropoma in 1828.[4] They were categorized under their own genus, Hypoplectrus, in 1861 after the discovery and description of H. indigo, H. gummigutta, H. nigricans, and H. guttavarius.[4]

There are many genetic similarities between each species of hamlet because they recently diverged (split into distinct species).[6] Each species generally has its own distribution, but a geographic barrier is not the likely cause of the speciation of hamlets.[9] Rather, evidence suggests that the hamlets diverged because of competition between different morphotypes for resources, food, etc.; ecological roles, specifically in habitats; and preference for mating with fish of similar color-morphs.[4][9]

Species of Hamlets
Scientific Name Common Name Year Discovered
Hypoplectrus unicolor Butter hamlet[11] 1792[4]
Hypoplectrus puella Barred hamlet[12] 1828[4]
Hypoplectrus chlororus Yellowtail hamlet[13] 1828[4]
Hypoplectrus indigo Indigo hamlet[14] 1851[4]
Hypoplectrus gummigutta Golden hamlet[15] 1851[4]
Hypoplectrus nigricans Black hamlet[16] 1852[4]
Hypoplectrus guttavarius Shy hamlet[17] 1852[4]
Hypoplectrus aberrans Yellowbelly hamlet[18] 1868[4]
Hypoplectrus maculiferus Bicolored hamlet[19] 1871[4]
Hypoplectrus gemma Blue hamlet 1882[4]
Hypoplectrus providencianus Masked hamlet[7] 1994[4]
Hypoplectrus maya Maya hamlet[20] 2011[4]
Hypoplectrus randallorum Tan hamlet[21] 2011[4]
Hypoplectrus ecosur Spotted hamlet[22] 2012[22]
Hypoplectrus floridae Florida hamlet[23] 2012[23]
Hypoplectrus castroaguirrei 2012[24]
Hypoplectrus atlahua Jarocho hamlet[25] 2013[25]

References edit

  1. ^ a b Anderson, W.; Carpenter, K.E.; Gilmore, G.; Milagrosa Bustamante, G.; Robertson, R. (2015). "Hypoplectrus providencianus". IUCN Red List of Threatened Species. 2015: e.T10724A46910291. doi:10.2305/IUCN.UK.2015-2.RLTS.T10724A46910291.en. Retrieved 17 November 2021.
  2. ^ Froese, Rainer; Pauly, Daniel (eds.) (2019). "Hypoplectrus providencianus" in FishBase. December 2019 version.
  3. ^ a b P., Arturo & Garzón-Ferreira, Jaime (1994). "Descripción de una especie nueva de Hypolectrus (Pisces: Serranidae) del Caribe occidental y comentarios sobre las especies colombianas del género". Boletín de Investigaciones Marinas y Costeras (in Spanish). 23: 5–14. doi:10.25268/bimc.invemar.1994.23.0.386. (English Abstract)
  4. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad Lobel, Phillip (2011). "A review of the Caribbean hamlets (Serranidae, Hypoplectrus) with description of two new species". Zootaxa. 3096: 1-17.
  5. ^ a b c Fischer, Eric (1980). "Speciation in the Hamlets (Hypoplectrus: Serranidae): A Continuing Enigma". Copeia. 4: 649-659.
  6. ^ a b c d Hollingworth, Chuck (2005). The Living Marine Resources of the Western Central Atlantic. Volume 2: Bony fishes part 1 (Acipenseridae to Grammatidae). FAO Species Identification Guide for Fishery Purposes and American Society of Ichthyologists and Herpetologists Special Publication No. 5. Fish and Fisheries.
  7. ^ a b c d e f g h i j k l m Acero P., Arturo; Garzón Ferreira, Jaime (1994). "Descripción de una especie nueve de Hypoplectrus (Pisces: Serranidae) del Caribe occidental y comentarios sobre las especies colombianas de género". Boletín de Investigaciones Marinas y Costeras. 23: 5–14.
  8. ^ a b "Shorefishes - The Fishes - Species". biogeodb.stri.si.edu. Retrieved 2021-04-01.
  9. ^ a b c Holt, B. G.; Côté, I. M.; Emerson, B. C. (2010). "Signatures of speciation? Distribution and diversity of Hypoplectrus (Teleostei: Serranidae) colour morphotypes". Global Ecology and Biogeography. 19: 432-441.
  10. ^ a b Lobel, Phillip; Neudecker, Steve (1985). "Diurnal periodicity of spawning activity by the hamlet fish, Hypoplectrus guttavarius (Serranidae)". The Ecology of Coral Reefs, NOAA Symp. Ser. Undersea Res. 3: 71-86.
  11. ^ "Hypoplectrus unicolor, Butter hamlet : aquarium". www.fishbase.de. Retrieved 2021-04-09.
  12. ^ "Hypoplectrus puella, Barred hamlet : aquarium". www.fishbase.se. Retrieved 2021-04-09.
  13. ^ "Hypoplectrus chlorurus, Yellowtail hamlet". www.fishbase.de. Retrieved 2021-04-09.
  14. ^ "Hypoplectrus indigo, Indigo hamlet : aquarium". www.fishbase.in. Retrieved 2021-04-09.
  15. ^ "Hypoplectrus gummigutta, Golden hamlet : aquarium". www.fishbase.de. Retrieved 2021-04-09.
  16. ^ "Hypoplectrus nigricans, Black hamlet : aquarium". www.fishbase.de. Retrieved 2021-04-09.
  17. ^ "Hypoplectrus guttavarius, Shy hamlet : aquarium". www.fishbase.de. Retrieved 2021-04-09.
  18. ^ "Hypoplectrus aberrans, Yellowbelly hamlet : fisheries". www.fishbase.de. Retrieved 2021-04-09.
  19. ^ "Shorefishes - The Fishes - Species". biogeodb.stri.si.edu. Retrieved 2021-04-09.
  20. ^ "Hypoplectrus maya, Maya hamlet". www.fishbase.se. Retrieved 2021-04-09.
  21. ^ "Hypoplectrus randallorum, Tan Hamlet". www.fishbase.se. Retrieved 2021-04-09.
  22. ^ a b "Hypoplectrus ecosur, Spotted hamlet". www.fishbase.se. Retrieved 2021-04-09.
  23. ^ a b "Hypoplectrus floridae, Florida hamlet". www.fishbase.se. Retrieved 2021-04-09.
  24. ^ "Hypoplectrus castroaguirrei". www.fishbase.se. Retrieved 2021-04-09.
  25. ^ a b "Hypoplectrus atlahua, Jarocho hamlet". www.fishbase.se. Retrieved 2021-04-09.

External links edit