INTRODUCTION TO THE GREATER CARIBBEAN
1. THE GREATER CARIBBEAN
Fig 1. Terrestrial Topography of the Greater Caribbean
1.1 Terrestrial and Marine TopographyGeographically the GC is very complex due to the winding nature of the continental coastline and the large number of islands of greatly varying sizes (Fig 1). Habitat available to shorefishes in different parts of the GC is determined by variation in the extent of shallow (<200m deep) continental and insular shelves. There are large expanses of such shelf between Nicaragua and Jamaica, on the broad shelf north of the Yucatan Peninsula and in the northern and eastern Gulf of Mexico, and the large insular shelf system of the Bahamas archipelago (Fig 2).
Fig 2. Submarine topography of the Greater Caribbean (NASA).
Fig 3. Regional Rainfall .
Fig 4. Regional Rainfall on land.
Fig 5. River catchments of the Greater Caribbean.
Fig 6. Seasonal variation in SST in the GREATER CARIBBEAN (RSMAS)
Fig 7. Seasonal change in average surface wind speed in the Neotropics (NASA)
2.3 Winds of the Greater Caribbean: As can be seen from Fig 7, average wind speeds are moderate in most of the region, and noticeably higher than speeds in most of the Tropical Eastern Pacific, on the western side of the Central American Isthmus. There is one area of consistently high wind activity in the GC, off the coast of Colombia where a high mountain range (the Sierra Nevada) extends very close to the coast (see Fig 1). Wind levels change seasonally in the GC, with more activity during the winter, when prevailing north-east trade winds blow most strongly and consistently over the entire region.
Fig 8. Neotropical hurricane tracks since the 1850s (NASA)
Fig 9. A hurricane in the Gulf of Mexico (NASA)
Fig 10. Tidal regimes of the Greater Caribbean
Fig 11. Global variation in the strength of the major tidal component (NASA)
Fig 12. Surface Ocean Currents of the Greater Caribbean (RSMAS)
GC = Guyana Current; CC = Caribbean Current; AC = Antilles Current; CPG = Colombia-Panama Gyre; YC = Yucatan Current; MC = Mexican Current; LC = Loop Current; FC = Florida Current; GS = Gulf Stream
Fig 13. Global variation in average salinity
Fig 14. Short-term variation in salinity in the Greater Caribbean area (Aquarius: NASA)
Animation at: http://www.youtube.com/watch?v=zUZHMbZuWVQ
Fig 15. Upwelling systems in the Greater Caribbean: A Sea Surface Temperature; B Productivity
Fig 16. Global variation in surface pH of the ocean (WHOI)
Fig 17. Areas of predominantly sand and mud shorelines in the Greater Caribbean.
Fig 18. Coastlines of with large mangrove formations in the Greater Caribbean.
Fig 19. Areas of rocky and coral shorelines and reefs in the Greater Caribbean
Fig 20. Coral reef distribution in the Greater Caribbean (UNEP_WCMC).
4.5 Seagrasses: Seagrasses represent another major habitat component for shorefishes in the Greater Caribbean and are found throughout the region. There are large areas in Florida, the Yucatan peninsula and Central America, and in Cuba (Fig 21).
Fig 21. Seagrass areas in the Greater Caribbean
This information system covers 1694 species (in 612 genera and 171 families). Of those 1,577 are native to and resident in the Greater Caribbean and are found in shallow (above 100 m depth) areas of the continental and island platforms, or in near-shore pelagic environments. The native shallow-water residents include 703 species endemic to the Greater Caribbean.
5.1 Major modern identification guides to Greater Caribbean shorefishes:Most of the general identification guides to GC shorefishes are aimed at a particular part of that area. Those include Bohlke & Chaplin’s (1968) Fishes of the Bahamas and adjacent waters; Hoese & Moore’s (1977) Fishes of the Gulf of Mexico: Texas, Louisiana & adjacent waters; Robins et al’s 1986 A Field Guide to the Atlantic Coast Fishes of North America; Smith-Vaniz et al’s 1999 Fishes of Bermuda, McEachran & Fechelm’s two volume (1998 & 2005) Fishes of the Gulf of Mexico; and Cervigon’s 6 volume ( 1991-1999) Los Peces Marinos de Venezuela. There have been few truly regional guides that effectively cover the entire GC. Among them are Randall’s (1968) Caribbean Reef Fishes (with subsequent revisions); Smith’s (1997) Aubdubon Field Guide to Tropical Marine Fishes of the Caribbean, Gulf of Mexico, Florida, the Bahamas and Bermuda. In 2002 FAO produced an updated, three volume guide to The Living Marine Resources of the Western Central Atlantic that covers fishes, invertebrates and marine reptiles of the entire GC. Humann & Deloach published a popular photographic guide to reef fishes of the GC, Reef fish identification: Florida, Caribbean, Bahamas, in 1989, with several updated editions since then. Other comprehensive popular guides with more limited geographic coverage include Kells and Carpenter’s (2011) A Field Guide to Coastal Fishes from Maine to Texas, which includes many excellent paintings of fishes in lieu of photographs.
5.2 Global online resources about shorefishes: Major online resources that effectively cover different aspects of the region's fishes via information on individual species, include William Eschmeyer's Catalog of Fishes, at www.calacademy.org/research/icthyology/catalog, which provides comprehensive up to date information on the systematics of fishes and FishBase [ www.fishbase.org ], which summarizes information from other sources on a variety of aspects of the biology of fishes; the International Taxonomic Information System, ITIS (http://www.itis.gov ), which covers the scientific names of fishes. Both OBIS, the International Biogeographic Information System (http://www.iobis.org ) and GBIF, the Global Biodiversity Information Facility ( www.gbif.org ) aggregate and make available information on georeferenced databases of collection records of fishes from individual museums and research organizations.
5.3 Systematic order in which fishes are arranged:The fishes are presented in phylogenetic or systematic order by family (the scientific names of which end in -idae); with the most primitive fishes presented first followed by more recently evolved forms. We follow the classification and sequence of families presented in J.S Nelson's 4th edition (2006) of Fishes of the World. The different genus pages within each family appear alphabetically by scientific name. as do the different species pages within each genus. The Systematic Tree in The Fishes section indicates each species position in a simplified systematic hierarchy that includes only 4 levels: Order, Family, Genus and Species.
5.4 Names of Fishes:
5.4.1 Scientific names:Many of the fishes found in the Greater Caribbean were given their names by ichthyologists in the latter half of the 19th century or the first half of the twentieth century. In some cases the same fish was given a different scientific name by different researchers. By the Law of Priority, the oldest name is the accepted one, provided it is binomial, was accompanied by a description, and was published at the scientific work that started our current system of biological nomenclature (on or after 1758 with the 10th edition of Carl Linnaeus' Systema Naturae). Subsequent, invalid names for previously described organisms are called synonyms. Most of the problems involving synonyms have been sorted out, but some older names are still being discovered, which means they must replace names in current usage. Because The Catalog of Fishes by William Eschmeyer of the California Academy of Sciences provides excellent coverage of this aspect for our fishes, we only occasionally mention synonyms. Here we follow names as presented in ITIS, The International Taxonomic Information System which provides information that supplements that in the Catalog of Fishes, and makes decisions about valid names. The scientific name is the name in two parts, the first being the genus name and the second the species name. Rarely three names are used, in the case of subspecies. This is immediately followed by the name of the author(s) who gave the fish its scientific name and the year in which the description was published. If the author's name is in parentheses, it indicates that the fish was originally placed in a genus that is different from the one that is currently accepted. A few species treated here still lack scientific names, because they have not been formally described; these are indicated by "species A, B etc", following the genus name.
5.4.2 Common names: The common names of fishes used here have been taken from a variety of sources. In many cases they are names that have been previously published in other books (e.g the FAO volumes). ITIS and the American Fisheries Society’s (2012; 6th edition): Common and scientific names of Fishes from the United States and Mexico. Fishes’ common names vary greatly from one country to the next, and even within different parts of the same country. No attempt has been made to fully cover this variation.
6 BIOLOGY AND ECOLOGY OF GC SHOREFISHES
6.1 Use of environments and habitats:The fishes included here are mainly (95.5%) restricted to inshore environments, including not only rocky and coral reefs and there immediate surroundings, but also soft (sand and mud) habitats in estuaries and beaches as well as in water extending well down the continental shelf. Species found on either reefs or soft bottoms exhibit precise habitat preferences that are dictated by a combination of factors including the availability of food and shelter, and various physical parameters such as salinity, depth, water clarity, currents, and wave action, as well as the precise nature of the bottom.
6.2 Reef-associated fishes: The majority of inshore fishes in the region likely to be encountered by divers and anglers are associated with what can be broadly defined as reef habitats. These include rocky shores and submerged rock reefs as well as coral reefs and hard bottoms (low relief rocky bottoms). Rock outcrops and ledges provide necessary shelter and a source of benthic invertebrates and algal growth, important dietary components for many reef fishes. Rocky reefs often have a dense covering of various types of seaweed, which provides additional shelter for a variety of small fishes. About 49.4 % of the regional fauna comprises bottom living fishes found in association with reefs. Some of the more prominent families found on rocky reefs include moray eels, groupers, snappers, grunts, damselfishes, wrasses, parrotfishes, blennies (three families), gobies, and surgeonfishes.
6.3 Soft-bottom fishes:Another large and important segment of the TEP fish fauna is associated with soft bottom habitats, which range from clean white sand in clear waters to soft thick mud, characteristic of turbid bays and estuaries, to mangroves and seagrass beds. Although this habitat is often considered to be low in fish diversity, about 60.9% of the species treated here live in such habitats. The soft bottom community includes such fishes as rays, snake eels, catfishes, lizardfishes, croakers, sand stargazers, and flatfishes.
6.4 Water-column fishes:The third most important group of fishes live in the water column above the substratum, over shallow reefs and soft-bottoms as well as the open ocean. These species constitute about 26.6% of the species included here. These include jacks, anchovies, herrings, and silversides, flyingfishes, tunas and billfishes, as well as a smattering of members from many other families.
6.5 Use of environments of differing salinities:Almost 69.6% of the shorefish fauna comprise species that are found only in marine (i.e.full salinity) environments, while another 29.4% occur in estuarine (reduced salinity) as well as marine situations. Only 7.5% are non-marine species (which do not enter full salinity environments), and only 12.5% enter freshwater. A few of the fishes included here (6.4%) are basically freshwater fishes that occasionally enter brackish water, or whose juveniles are encountered in brackish water.
6.6 Depth distribution patterns:Most of the regional fauna considered here lives in fairly shallow water – 42.3% of species reach the surface, the depth ranges of 71.2% extend to within 5 m of the surface, and only 12.1% do not come above about 50 m. The lower limit of the depth ranges of 38.6% of the species terminate at about 30 m, with only 48.5% occurring down to 50 m and 38.7% below 100 m.
6.7 Fishes dietary groupings:The great majority of Greater Caribbean shorefishes are carnivores of one type or another: 79.1% of the species have such a diet, which includes items ranging from tiny benthic mollusks, worms and crustaceans to sharks, whales and marine birds. The next most abundant group comprises species that consume plankton (either exclusively or with a mix of non-planktonic animals): 28% of the fauna. Bottom feeding omnivores and herbivore/detritivores are relatively uncommon, constituting only about 8.7% and 6.7% of the fauna, respectively.
6.8 Modes of reproduction:The diversity of shore fishes found in the GC is reflected in a wide variety of reproductive habits. The great majority of shorefishes treated here are egg layers that employ external fertilisation. Relatively few species (12.5% of those included here) bear live young that are prepared to fend for themselves at birth. These include most of the sharks and rays, but very few bony fishes: the brotulas and two genera of weed blennies.
Most shorefishes use one of two patterns of egg-laying reproduction. Females of many fishes, including the highly visible wrasses and parrotfishes, scatter relatively large numbers of small, positively buoyant eggs into open water where they are summarily fertilized by the male. Of the species included here 53.6% reproduce in this manner.
The spawning event is typically preceded by nuptial chasing, temporary color changes, and courtship displays in which fins are erected. This behavior is generally concentrated into a short period of the day, often at sundown or shortly afterwards, or is related to the stage of the tidal cycle. This pattern is seen in diverse groups such as lizardfishes, angelfishes, wrasses, parrotfishes, and boxfishes. Typically either pair or group spawning (the latter involving a single female and multiple males) occurs in which the participants make a rapid dash towards the surface, releasing their gonadal products at the apex of the ascent. The fertilised eggs float near the surface and are dispersed by waves, winds, and currents. Hatching occurs within a few days and the young larvae are similarly at the mercy of the elements. Older larvae, however, are good swimmers and have considerable control over their movements. Recent studies of the daily growth rings found on the ear bones (otoliths) of reef fishes indicate that the larval stage generally varies from about 1-8 weeks depending on the species involved. The extended pelagic larval period accounts for the wide dispersal of many reef species.
The second major reproductive pattern (exhibited by 29.5% of shorefish species in the TEP fauna) involves fishes that lay their eggs on the bottom, frequently in rocky crevices, empty shells, sandy depressions, or on the surface of invertebrates such as sponges, corals, or gorgonians. These include the skates and a few of the sharks, which produce large benthic eggs in horny egg cases. Among the best known fishes in this category are the damselfishes, blennies, gobies, and triggerfishes. These fishes often prepare the surface prior to egg deposition by cleaning away detritus and algal growth. Bottom spawners also exhibit elaborate courtship rituals which involve much aggressive chasing and displaying. This behavior has probably been best studied amongst the damselfishes. In addition, one or both parents may exhibit a certain degree of nest-guarding behavior in which the eggs are kept free of debris and guarded from potential egg feeders such as wrasses and butterflyfishes.
A more specialized mode of parental care is seen in cardinalfishes and sea-catfishes, in which the male broods the egg mass in its mouth. Similarly, male pipefishes and seahorses brood their eggs on a highly vascularised region of the belly or underside of the tail. Only 4.3% of our region's fishes reproduce using brooded eggs. As a rule the eggs of benthic nesting and oral-brooding fishes are less numerous, larger, have a longer incubation period, and are at a more advanced developmental stage when hatched, compared to the eggs and larvae of pelagic spawning fishes.
6.9 Longevity and size:There is little information on the longevity of most eastern Pacific reef fishes. Perhaps one of the longest life spans is that of the Lemon Shark, Negaprion brevirostris, which may reach 50 years or more. Most of the larger reef sharks probably live at least to an age of 20-30 years. In general the larger reef fishes such as groupers and snappers tend to live longer than smaller species in the same family or genus. However, small snappers can live as long as much larger groupers. The largest grouper in the western Atlantic is the Goliath grouper (Epinephelus itajara), which reaches 2.5m, 363 kg and lives up to 37 years.Whatever information is available on the maximum size of each species, from the literature as well as our personal experience, is distilled to maximum known total length in both the text and database. A few data is also presented (in the species pages) on maximum total weights when that is known. Most of the species in the shorefish fauna are small: 30.3% are 10 cm or less and 56.5% 25 cm or less. Large species of fishes are uncommon: only 12% are 1 m or longer, and only 4.7% 2 m or longer.
7 MARINE BIOGEOGRAPHY OF THE GREATER CARIBBEAN
The Tropical West Atlantic (TWA), which spans about 600 of latitude, from the southeast US to Brazil, includes two regional centers of species richness and endemism for reef fishes and other reef organisms: the Greater Caribbean and Brazil. The Caribbean and Brazilian reef areas are separated by a ~1200km wide expanse of coastline and inner shelf that is almost entirely free of habitat suitable for reef organisms. The mud, sand and mangrove habitats inshore in that zone are produced by the outflows of large rivers, the largest being the Orinoco in the north and the Amazon in the south. While those two reefal regions each have a substantial proportion of endemic species most of the species found in the TWA are shared between them. The Greater Caribbean is the high diversity heart of the TWA as it has about twice as many species and twice the level of endemism as Brazil. Among the Greater Caribbean shorefish fauna, 46% live on mud and sand bottoms, 39% are reef fishes, and 18% are pelagic species.
Here we cover 1,694 species, 1,577 of them shallow water (found shallower than 100 m depth) shore fishes. With 703 species of shallow-water endemic shorefishes the Greater Caribbean has a substantially lower rate of endemism (45%) than the Tropical Eastern Pacific, where the rate is 78%. Reef fishes of the GC have the highest rate of endemism (60%) and the pelagics the lowest (18%), while the soft-bottom fishes are in between (46%).
Fig 22. Eight schemes for the biogeography of the Greater Caribbean
Fig 23. Biogeography of the shorefishes of the Greater Caribbean
Fig 24. Similarity in the marine environments of different parts of the Greater Caribbean.