Zoogeography of the Penaeidae

12 Pages·1991·3.3 MB·English

by  W Dall

ZOOGEOGRAPHYOFTHE PENAEIDAE
W.iMl.l
DalI,W. 1991 09 1:ZoogeographyofthePenaeidae.MemoirsoftheQueenslandMuseum
31: 39-50. Brisbane. ISSN 0079-SS35.
The Penaeidae are tropical >teno[herms. mostly inhabiting shallow. Sjjl) inshore environ-
ments. Their present distribution appears 10 be largely determined by a combination of
geological history, temperature. ocean currents, ocean deeps and coastal geography.
Penaeids are almost six times more diverse in the Indo-Wesl Pacific Region than in the
WesternAtlantic,which maybe related tocontinentalshelfareaorthe length ofshoreline.
Most extant genera probably originated in the Tertiary, and there is evidence that seme
species have separated within the last 1 million years. Except for 3 fev\ pelagic and
deep-water species, the penaeid populationsofthe Indo-West Pacific, Eastern Pacificand
Western Atlantic Regions are discrete. Within each region, two or more subregionshave
been defined,supported by cluster analysis of the Indo-West Pacific Region. Reasonsfor
these divisions arc discussed, particularly the barriers to penaeid movements from the
Indo-Malaysian totheTropicalAustralia Subregion. Thesebarriersappear tobeprimarily
deepwaferand unfavourable currents along the steepnorthern and southwestern coasts of
iuinea. Possible causes oi Southern Hemisphere endemism in [he Penaeidae are
discussed. Because oftheabsenceoffossilrecordsextinction hypothesescannotbe tested,
buttheapparentahsenceOfamphitropieatih in the farnib and the limitedgeographicrange
ofmanv species suggest that evolution uithin the Southern Hemisphere can account \\n
theendemism ofpenaeid species there. The unique genera Mucropeiasmo and Artemesia
couldbe relictsofMiocene, relative!] cool-waterpopulations,butthere isnofirmevidence
to support this. Ptttiaeuiat ZOOgeography, tropics, endemism, (emperaiure, ocean
,
currents, oceandeeps, Indo-WesiPacific, Eastern Pacific. WesternAtlantic
Kf Dall Division ofFisheries, CSIRO Marine Laboratories, P.O. Box 120, Cleveland,
.
Queensland4163, Australia; 1/Julv. 1990,
The Penaeidaeisthebest-knownfamilywilbin Trachypenaeopsis\ prefer harder substrates
the PcnacoideainthedecapodSuborderDendro- such as coral rubble. There is one commensal
branchiata. The 171 known species within 17 with corals {Metapenaeopsis vommensalis).
genera (Table 1 ) are predominantly tropical and Both biotic and physical factors are likely 10
subtropical. About 80% ofthese species usually influence the distribution of marine crustaceans
live indepthsof<100m; the remaindernormally such as The Penaeidae. They are subject to con-
either inhabit deeper water (10Metapenaeopsis siderable prcdation pressure (Dall et <;/., 19911);
spp.; most Parapenaeus spp.; all Penaeapsts in some areas the population density is high and
spp.) or are pelagic (all Funchalia spp. and interactions between species may be important.
Pelagopenaeas). Many of the deep-water and However, while no studiesontheeffectsofsuch
pelagic species appear to be widely distributed, biotic factors have been made, the physical en-
Funchalia viilosa and F. waodwardi, for ex- vironment appears to be more important in de-
ample, having been recorded in the Pacific. terminingthe distribution ofpenaeids.Their life
Atlantic and Indian Oceans. Records ofthe dis- histories suggest there are four principal factors
tribution of these pelagic species are, however, that may affect their distribution :
toosparse todiscusstheirzoogeography,somost 1. Temperature. As tropical stenotherms they
of this review is devoted to the better-known are restricted to the warmerwatersofthe world.
shallow-waterPenaeidae. In lower latitudes, cold winds from continental
All shallow-water Penaeidae so far investi- land masses may cool inshore waters or cause
gatedhaveaplanktoniclarvalphaseofabout2-3 upwclling and thus be barriers to distribution;
weeks, followed by inshore or estuarine early cold currents from higher latitudes may have u
juvenile stages (Dall et a/., 1990). Most species similar effect. Conversely, warm currents may
prefersoft substrates, ranging from mud tosand, extend the latitudinal range ofpenaeids along a
but a number — probably around 25% — coast.
(mainly Metapenaeopsis spp.. Heteropenaeus, 2.Oceaniclarvaladvection.Thepelagiclarval
40 MEMOIRS OFTHE QUEENSLAND MUSEUM
TABLE 1. Genera ofthe Penaeidae, the world-wide central Europe, the eastern Mediterranean and
numberofspecieswithineachgenusandthenumber Great Britain (Glaessner, 1969), with a few in
of species within each region. IWP, Tndo-West North America (Herrick and Schram, 1978).
Pacific; EP, Eastern Pacific; WA, Western Atlantic; Crustacea are, however, poor candidates for
EA, Eastern Atlantic; (P), pelagic, probably present
fossilisation, particularly the thinner-shelled
inalloceans;numberinparentheses, additionalspe-
cies also present in Western Atlantic. groupssuchaspenaeids(Bishop, 1986). Further,
thenormalenvironmentalconditionsofpenaeids
are not conducive to fossilisation because ofthe
Genus Total Speciesperregion presence ofnumerous scavengers and bioturba-
species IWP EP WA EA tionofthesedimentbyalargeburrowinginfauna
(Plotnick, 1986). Hencethepenaeidfossilrecord
Arlemesia 1 1 is very sparse. The Penaeidae first appear in
Atypopenaeus 4 4 - - Jurassic deposits and become more common in
Funchalia 4 (P) (P) (P) (P) the Cretaceous. Most ofthese earlier Penaeidae
Heteropenaeus 1 1 - - became extinctat the end ofMesozoic,Penaeus
MMMeeattcaarppoeepnneaateeaouspsmsais 42159 42150 3 -5- --1 bPneoeinfnaogsesutishlesrooefnclomyrodrsuefrrrvoeimcveiInnntgdoigraeinignuisnt.hheaAvpeeaarrblteyefTnreroftmoiuaonrndye,,
Parapenaeopsis 16 14 1 - 1 smoaigneionlgog1ic6aelxteavnitdegnecneeroafisthceomoprligeitneslyoflatchkeinrge.-
Parapenaeus 12 10 1 1 The times at which existing genera diverged
Pelagopenaeus 1 1 - - have therefore to be estimated by other means.
Penaeopsis 6 5 1 (1) Limited data are available from biochemical
Penaeus 28 14 5 8 1(1) genetics, supportedbypalaeogeography (Dall et
Protrachypene 1 1 - - al., 1990). These authors calculate from geneti-
Tanypenaeus 1 - 1 - cal data that Metapenaeuscould have separated
Trachypenaeopsis 2 1 1 - from Penaeusbetween the earlyTertiary and the
Trachypenaeus 17 10 5 2 - Pliocene. The genetic distances within these
Xiphopenaeus 2 1 1 - genera indicate that some present species
evolved between the Miocene and the Pleisto-
Total 171 125* 16* 21* 4 cene. While estimates ofdivergence times from
biochemical genetics are imprecise, they can be
• notincludingFundxaliaandPelagopenaeus. improved by palaeographical evidence. Separa-
tion of the Atlantic Ocean from the rest of the
life makes most species susceptible to the in- Tethys Sea by closure of the Mediterranean
fluences of currents flowing in unfavourable during the Miocene isolated its warm shallow-
directions, such as towards higher latitudes or water fauna (Por, 1986). Although North and
from inshore to offshore. SouthAmericawerenotjoinedduringtheOligo-
3. Oceanicdeeps.Theseconstituteabarrierfor cene-Miocene and the present Isthmus of
shallow-waterspecies, especially when they are Panama was not established until the Pliocene
very close inshore or in conjunction with un- (White, 1986), physical conditions in the proto-
favourable currents. Caribbean and Pacific hadbegun todifferby the
4. Coastal geography. Since most species live late Miocene (Keigwin, 1978). Fossil evidence
in shallow waters, particularly in the early ju- also suggests that thetwo faunaswere distinctat
venile stages, lack of suitable inshore habitats this time (Ekman, 1953). Penaeid genera com-
may constitute a barrier. Thus a desert coastline mon to the Atlantic, Pacific and Indian Oceans
withhigh inshoresalinities,oravery rockycoast today were presumably in existence before the
with deep water inshore, may restrict the dis- separationoftheAtlantic.Thesearctheshallow-
tribution ofsome species. water genera Penaeus, Metapenaeopsis,
Parapenaeopsis, Trachypenaeus and Trachy-
DISTRIBUTION IN TIME penaeopsis. On this basis, excluding the deep-
water or pelagic genera (Funchalia,
The Penaeidae are an ancient group. Penae- Parapenaeus, Pelagopenaeus and Penaeopsis),
oidea have been recorded in the Mesozoic, back seven may have originated since the Miocene.
totheUpperTriassic,mostly invariousshalesof Thus the combined evidence suggests that the
ZOOGEOGRAPHY OFTHE PENAEIDAE 41
FIG. 1. Locationof20°Cand 15°Cminimum winterseasurfacetemperature isotherms.They correspondwith
the isocrymal lines(coldest 30consecutive daysoftheyear)ofthe Northern and Southern hemispheres.
majority of present penaeid genera may have as in the Pohai Sea (Angelescu and Boschi,
originated in the last 10-15 million years. 1959).
WORLD DISTRIBUTION REGIONAL DISTRIBUTION
The Pcnaeidae are distributed throughout the
Ekman (1953) divided the shallow, warm-
world,buttheirlatitudinal distribution is limited watermarinefaunasoftheworldintoIndo-West
by temperature- Most species occur within the
Pacific, Eastern Pacific, Western and Eastern
isotherms of 20UC minimum winter tempera-
Atlantic Regions. This classification has been
tures (Fig. 1). Between the 20°C and 15°C followed by Briggs (1974) for various tax-
isotherms the number of species falls to about onomic groups and by Abclc (1982) for
3i)% ofthose withinthe 20°Cisotherms.In these Crustacea.TheAtlanticisclearlyseparatedfrom
cooler zones, the growth and activity of most other oceans by the Americas and the Afro-
species are minimal in winter, but temperatures European landmasses, and the deep ocean sepa-
in summer are usually high enough for them to rates the Atlantic into eastern and western
achieve growth rates comparable with those of faunas. The Eastern Pacific fauna is separated
fullytropical species.Onlytwospeciesareabun- from the rest ofthe Pacific by awide expanse of
dant outside the 15°C isotherms: Penacus chi- deep ocean, containing very few islands. East-
nensis in the Pohai and Yellow Seas and ward movement of warm-water planktonic
Artemesia longinaris in southeastern South larvae isdiscouragedbythewestwardEquatorial
America. Both haveadaptedtosurvivetempera- Current, which is fed in this region by cold
lures down to about 6°C, but, in addition, the currents flowing towards the equator along the
west coasts of North and South America. Only
adaptive behaviour ofP. chinensis enables it to species with anexceptionallylonglarval lifecan
cope with the hostile winterenvironment. It mi- betransportedeastward from theCentral Pacific
grates into the deeper waters of the Yellow Sea (Schcllcma, 1988). The fauna of the Eastern
at the onset of winter and returns to exploit the Pacific Region does, however, have someaffini-
rapid warming of the shallow waters in spring ties with ihal ofthe central Western Atlantic, as
and subsequent summer temperatures of 25"C the final separation of the two oceans did not
(Chang Cheng, 1984). A similar strategy is not occur until the early Pliocene and twin species
available \oArtemesia, aswater temperatures in are common (Ekman. 1953). Examples in the
the southern halfof its range do not rise above Pcnaeidae are Trachypenaeus pacificus . T.
20°C, butwinter temperatures are not as severe simitis and Xiphopenaeus rived : X. kroyeri
42 MEMOIRS OFTHE QUEENSLAND MUSEUM
(western and eastern coasts of the Isthmus, re- and P. semisulcatus have been recorded in most
spectively). of the warmer waters of the Indo-West Pacific.
The remainder of the Pacific is not separated In the Eastern Pacific, all Penaeus species are
zoogeographically from the Indian Ocean and found in both subregions, while in the Western
thetwoareusuallygroupedtogetherasthe Indo- Atlantic they extend through at least two sub-
West Pacific Region. Springer (1982), from a regions, with P. notialisoccurring on both sides
study ofshallow-water fishes, proposed that the of the Atlantic. The deeper water genera Para-
Pacific Plate should be designated as a separate penaeus and Penaeopsis are also wide ranging,
region, but this is not supported by the distribu- but generally less so than Penaeus. The remain-
tion of corals and echinoderms (Ekman, 1953), ing genera are mostly more restricted in range,
nor by that ofthe Penaeidae (Dall et a/., 1990). about50% ofall penaeid species being endemic
Although the numberofpenaeid genera in the to one or two subregions. (Some species within
Indo-WestPacificandWesternAtlanticRegions these genera with an apparent wide range, such
is similar, there is great disparity in the number as Metapenaeopsis mogiensis and M. hilarula,
of species (Table 1). Excluding Funchalia and may be complexes ofspecies, A. Crosnier, pers.
Pelagopenaeus, the Indo-West Pacific contains comm.).
73% of known species, compared with 12% in Dall et al (1990) define and discuss penaeid
the Western Atlantic. Abele (1982) found simi- subregionswithineachoftheregions.They used
lar ratios for other decapod Crustacea (Por- thedistributionofspecieswitharestrictedrange,
tunidae, Parthenopidae, Sesarma spp. and particularlythoseendemictoaparticulararea,to
Alpheus spp.). He also notes that the ratios are define subregions. Geography and temperature
due to the large numberofcongeneric species in data were also taken into account. These were
the Indo-West Pacific, rather than an increase in confirmed for the present study for the Indo-
the number of genera. Abele (1982) discusses West Pacific Region by cluster analysis of the
severalhypothesestoaccountforthis.Onasmall presence-absence data ofall specieson thebasis
scale there isapositive correlationbetween hab- ofeuclidean distancewithgroupaverage hierar-
itat complexity (e.g. sandy beaches, sand-mud chical clustering (Fig. 2). Bray-Curtis group
beaches,mangroves,coralsand rocky intertidal) average hierarchical clustering gave similar
and crustacean species diversity, but this does groupings, but with Southeast and Southwest
not appear to be valid for zoogeographical re- Australia separated from the other subregions
gions. It would also be unlikely to apply to the and closestto the West Pacific. (Reliable cluster
Penaeidae, which occupy similar habitats both analysesforthesubregionsdefinedby Dalletal.
latitudinally and longitudinally. Briggs (1974) (1990) for the Eastern Pacific and Atlanticwere
suggests that the number of species of tropical
shallow-water marine animals is directly corre-
lated with continental shelf area. Abele (1982) 1.2
obtained a positive linear correlation between fufi 1.0
continentalshelfareaandnumbersofwarmshal- cn
low-water marine crustacean species in the four n 0.8 I
major regions. He also obtained a positive log- sa 0.6
log relationship between Caribbean island per-
imeter and number of marine shrimp species <> 0.4 "
(penaeids and carids). Shoreline length may be 0.2
the reason for the higher penaeid species diver-
sity in the Indo-West Pacific, as the factors that 0.0 s SE S-W W Arab Sino- Trop Indo-
Afr Aust Aust Pac Sea Jap Aust Mai
tend to isolatepenaeid populationsare related to
Sub-region
theshoreline.
FIG. 2. Groupaverage hierarchicalclusteranalysisof
Indo-West Pacific Subregions, using presence-ab-
Subregions
sencedataofallspecies,basedoneuclideandistance.
There are considerable differences in geo- Abbreviations: E Afr, East African; S Afr, South
graphical ranges in the Penaeidae, both between African; SE Aust, Southeast Australian; SW Aust,
and within genera (Dall et a/., 1990). Thus the SouthwestAustralian;WPac,WestPacificOceania;
most ancient genusPenaeus is, with few excep- Arab Sea, Arabian Sea; Sino-Jap, Sino-Japanese;
tions, the most widely ranging. Penaeusjaponi- Trop Aust, Tropical Australian; Indo-Mal., Indo-
cus, P. latisulcatus, P. marginatus, P. monodon Malaysian.
ZOOGEOGRAPHY OFTHE PENAEIDAE 43
FIG. 3. Subregions ofthe Indo-West Pacific Region. 1, Indo-Malaysian; 2, Tropical Australian;
3, Sino-Japanese;4, Arabian Sea;5, EastAfrican;6, South African; 7r SouthwestAustralian;8,
SoutheastAustralian;79,PacificOceania;arrows,extensionofMalay-IndonesianSubregion(see
textfordefinitions).
not feasible because ofthe paucity ofspecies in movementofpenaeids.Thesouthern tipofIndia
these areas). has been arbitrarily selected as the western
boundary ofthis subregion.
Indo-WestPacificSub-regions 2. TropicalAustralia. This subregion extends
(Fig. 3; Table 2). from the southern coast of New Guinea to the
1.Indo-Malaysian.Thisisdefined in thesouth 20°Cwinterisotherm on theeastandwestcoasts
by the oceanic deeps off southern Indonesia, of Australia. The significance of the barriers to
which extend into the Timor Sea, to the west of the northeast and northwest are discussed in
theAru Islands,comingcloseinshoreattheneck detail below.
of West Irian. To the east, oceanic deeps and
westward equatorial currents form a major bar- 3. Sino-Japanese. The southern boundary is
rier,whiletothe northfallingtemperaturesclose defined by the 20°C isotherm. Thediverse fauna
offthe subregion.There is no obvious barrier in of the Gulf of Tonkin and southern China
thewest,theshallowcoastalwatersoftheStraits decreases sharply to the north due to cold conti-
of Malacca running without apparent interrup- nental influences, but the Equatorial Current
tion through the Bay of Bengal. However, there runs offshore to the northeast, raising the min-
is a steady decrease in the diversity of penaeid imum wintertemperature in the Sea ofJapan and
species diversity from Malaysia to the Bay of giving this area a large and distinctive penaeid
Bengal (Dall et aL, 1990), as in other faunas fauna.
(Ekman, 1953). Dail et al (1990) suggest that
unfavourable currents, plus the strongly mon- 4.ArabianSea. This subregion, from the south-
soonalclimateofIndiamayrestrictthewestward ern tipofIndiatoCape Guardafui at theentrance
M J|RS OFTMF. QUEENSLAND MUSEUM
i
TABLE -. Total number ul species anel enuVmu ^pecie.s in the subregions of ihe Indo-West Pacific Region.
Indo-Mal. IndoMalayshrr TrnpAust, Tropical Australia: Sino-Jap. Sinu-.lapancse: Arab Sea.ArabianSea:
E Air. East Africa; S Aft, South Africa: SV Auiii Southwest Australia; SE Aust. Southeast Australia; O,
PadHeOceania
Indo TrOji Sinu- Arab E .\l'r S Afr s\v SE O
Mai. Aust .lap. Sea Ausl Aust
TcUalspecies B4 _S2 36 3S 20 15 8 s 20
Endemic species 22 13 10 3 -i 3 5
to the Red Sua, hasextensive arid coastlines; the 9,PacificOceania. The penaeid population of
hvpersaline inshore waters and cold continental this subregion appears to be mostly an extension
winter winds probably act as barriers to less id ihc Indo-Malaysian fauna; it is therefore
adaptablespecies.The RedSea isusually trc. doubtful that it is a valid penaeid subregion
asa separate subregion because of its distinctive (indicated by the query in Pig. 3). Two endemic
fauna (Ekman, 1953; Briggs. 1974). but the species have been identified: XJetapenaeopsis
penaeid fauna differs only in having fewer spe- tartiweitsis and ftf. commensalis, both inhabi-
cies and has therefore been included in this sub- tants ul' coral reefs and the latter a commensal
region. with corals. U. commcnsultsmay be more wide-
spread than the published record indicates.
5. EastAfrican Coast, Thisextendsfrom Cape
Guardafui to Durban. Briggs ( 1974) regards the
coast from the Gulfof Iran to the southern tip of WESTERN AtlanticSuBREcaoNs
Africa as one subregion, but the Last African (Tig 4; Tabic 3.)
Coast appears to support a more diverse and The Western Atlantic Region extends from
possibly largerpenaeid population than the Ara- Martha's Vmevatd, 4.VN to Puerto dc Rawson,
bian Sea (Crosnier. 1965). Neither the northern 43°S. The subregions are:
northesouthern boundariesarewell defined, bul
there is a drop in species diversity around the Li Caribbean. This extends from southeast
latitude ofsouthern Madagascar. Florida through the Caribbean to Sao Luis,
Brazil, but stops at the entrance of the Gulf of
o. South Africa. This subregion could be in- Mc\ico. GeographicalIythisare3 isanalogousto
cluded in EastAfrica, except for the appearance the Indo-Malaysian Subregion of the Pacific. It
ofMacropaasmaafricanusat Durban. Thisspe- has the greatest penaeid species diversity (16)
cies becomes common on the south coast, west within the Atlantic Ocean, with three endemic
of Algoa Bay, where other penaeid species are species (Tanypenaeus caribeus, Trachypenae-
rare, and is unique in that it extends northward opsis mobilispinis, Trachypenaeus sitm/is). The
along the west coast of southern Africa from eastern boundary isdefined by a marked drop in
Cape Town to Swakopmund, in the cool waters species diversity, which appears to be due to a
derived from the Bcnguela Current. strong westward current, plus a monsoonal cli-
mate in eastern Brazil.
7. SouthwesternAustralia.The 2Q°C isotherm
defines the northernboundary of thissubrcgi-ML 2. EasternBrazil(Sao Luis toCaboFrio).The
whichextendsacrosssouthernAustraliabecause southern boundary at Cabo Frio is caused by a
ofthe influence ofthe warm southerly Leeuwin Ldokr-watcr coastal northerly current meeting
Current. There are two endemic species: Meta- thewarm southerly BrazilianCurrentanddivert-
penaeopsisfusca and M. Undue, ing it offshore. There arenoendemicspecies,but
the species composition is appreciably different
8. Southeastern Australia. The 20° C and 15" from ihat ofthe Caribbean.
C isotherms define the northern and southern
limits of this subregion. it has three gndem i 3. GulfofMexico. This is defined by Penaeus
species, Penaeus picbejus. Menipenacus hwt- azlecus, P. duorarumand P.senferus, which
nettae and M. macleayi; the first two appeal u> plentiful intheGulfofMexico,butdonotextend
be siblingsofwidely distributed species eastwards into the adjacent Caribbean Sub-
ZOOGEOGRAPHY OFTHE PENAE1DAE 45
FIG.4.SubregionsoftheWesternAtlantic,EasternAtlanticandEasternPacificRegions.Western
Atlantic: 1, Caribbean; 2, Eastern Brazil; 3, Gulfof Mexico; 4, Eastern USA (Carolinean); 5,
Southeast South America. Eastern Atlantic: 6, Eastern Atlantic; 7, Mediterranean Sea. Eastern
Pacific: 8,Panamanian; 9, Mexican (see text fordefinitions).
region. Also, low winter temperatures in the Indo-West Pacific species (Penaeusjaponicus,P.
north ofthe Gulfreduce the species diversity (7 semisulcatus, Metapenaeus monoceros, M. steb-
compared with 16 in the Caribbean). bingi, Trachypenaeus cun'irostris) have migrated
through the Suez Canal from the Red Sea (Les-
4. Eastern USA (Carolinean) (Martha's Vine- sepsian migration)(Gab-Alla et aL, 1990). In the
yard to southeast Florida). Cape Hatteras is the Atlantic,penaeids normally extend as farnorth as
northern limit ofabundant penaeid distribution, about 40 N in Portugal, but in the south the cold
but there have been records ofPenaeus aztecus Benguela Current limits the distribution to about
as far north as Martha's Vineyard. I6°S in Angola.Thusthe subregionsare:
5.SoutheastSouthAmerica(CaboFrio,Brazil to 6. Eastern Atlantic (Lisbon, Portugal, 40°N, to
Puerto de Rawson, Argentina). Penaeuspaulensis PortoAlexandre, Angola, 16° S).
and Artemesia longinaris are endemic species in
thiswell-definedcooler-watersubregion. 7. Mediterranean Sea. This subregion has only
twoofthesixspeciesfound inthe EasternAtlantic
apart from the Lessepsian migrants.
EasternAtlanticSubregion
Theseareshownin Fig.4anddetailed inTable
3.The Eastern AtlanticRegion includes the Medi- Eastern PacificSubregtons
terranean Sea, usually considered to be a sepa- (Fig. 4; Table 3)
rate zoogeographical area. Also, at least five Eastern PacificRegion is reduced latitudinally
MEMOIRS OFTHE QUEENSLAND MUSEUM
4<>
TABLE 3. Total number ofspecies and endemic species in the Subregions of the Western Atlantic, Eastern
Atlantic and Eastern Pacific Regions. Car, Caribbean; E Br. Eastern Brazil; GoM, Gulfof Mexico; E US,
Eastern USA (Carolinean); S SA, Southeastern South America; E A, Eastern Atlantic; Med, Mediterranean
Sea; Mex, Mexican; Pan, Panamanian.
Car EBr GoM EUS SSA EA Med Pan Mex
Total species 16 11 7 7 4 6 2 12 11
Endemicspecies 3 D 2 2 5 3
in both the north and south by cold currents apossible subregionbetween Portugal and Cape
flowing towards the Equator; the continental Verde on the western tip ofAfrica.
—
shelf is mostly narrow and there are relatively Within the tropics, the less obvious limits
few islands to support populations of pcnaeids. ocean currents, oceanic deeps, coastal geogra-
—
Penaeid species composition changes markedly phy appear to be responsible for most of the
in the El Salvador region, which has been discontinuities in penaeid distribution. Ex-
selected asaboundary between the northern and amples ofhow these barriers may operate in the
southern subregions. These are: Tropical Australian Subregion, which is ap-
parently contiguous with the Indo-Malaysian
8. Panamanian. El Salvador to Punta Aguja, Subregion, are described below and shown in
Peru. The uniqueProtrachypene,Parapenaeop- Fig. 5. (The well-known water barriers ofWal-
sisballi(theonlyParapenaeopsisintheWestern lacia that separate the terrestrial floras and
Hemisphere) and three species of Trachy- faunasofAustralia-New Guinea from southeast
penaeus define this subregion. Asia are due to long-term movements of the
tectonic plate [see review by Whitmore, 1981];
9.Mexican. San Francisco Bay (northern limit these barriers are not relevant to marine faunas
of penaeid records) to El Salvador. Here the with dispersive planktonic larvae.)
penaeid diversity is lower than in the The Indo-Malaysian penaeid fauna attenuates
Panamanian, with three endemic species Meta- along the north coast of New Guinea from west
penaeopsis beebei, M. kishinouyei and Trachy- to east. In eastern New Guinea and the Solomon
penaeusbrevisuturae. Islands, only 17 species, fourofwhich are deep-
sea, are common to the Indo-Malaysian Sub-
BARRIERS TO DISTRIBUTION region, which contains 84 species. All ofthe 13
shallow-water species are wide-ranging:
Low temperature, and thus latitude, has been Penaeusspp. (7); Metapenaeusspp.(4);Hetero-
mentioned as one ofthe principal boundaries to penaeus longimanus ; Trachypenaeopsis
penaeid distribution. These boundaries may be richtersii. The New GuineaTrench runscloseto
modified by warm currents flowing away from the steep mid-northern coast of New Guinea,
the equator, orcold currents flowing towards it. resulting in avery narrow continental shelf(Fig.
Thus the northern boundaries ofthe South Afri- 5). Furtherto the east the end ofthe New Britain
can, Southwest and Southeast Australian Sub- Trench comes close inshore. Except for the
regions, and the southern boundary of the Sepik River, there are no majorrivers along this
Sino-Japanese Subregion, defined by the 20°C coast and no extensive marine estuaries. The
winter isotherm, extend outside the tropics (Fig. westwardEquatorial Currentflowscloseinshore
1). In all cases there is a marked drop in species formostoftheyear(Lindstrometal, 1987).The
diversity outside the 20°C isotherm, with the southeast coast of New Guinea is similar geo-
appearance of one or more endemic species graphically to the north coast, but has an along-
(Table 2). There are comparable subregions in shoreeastwardcurrent(CSIRO,unpubl.),which
theWestern Atlantic. IntheEasternAtlanticand thus discourages westward migration of
Eastern Pacific, where cold currents flowf Penaeidae (such as Metapenaeus afftnis andM.
towards the equator, the north-south extent of anchistus) from the eastern end ofNew Guinea
the subregions is considerably less than in the towardsTropical Australia.
Western Atlantic(Fig. 4) and Indo-West Pacific To the northwest ofAustralia the Java Trench
(Fig. 3). In addition, thepaucityofspecies in the extends along southern Indonesia, reaching in
EasternAtlanticdoesnotpermitthedefinitionof the east, past the island of Sumba; deep water
ZOOGEOGRAPHY OFTHE PENAEIDAE 47
v>s Tr?nch
^g^^
120° 130° 140° 150°
FIG. 5. Geographical features that tend to isolate the Tropical Australian Subregion from the
Tndo-Malaysian Subregion. Arrows indicate surface currents.
continues to the northeast as the Timor Trough, discontinuity between Indo-Malaysian and
followedbytheAruBasin,comingclose inshore Tropical Australia faunas indicates that some
at the neck of New Guinea (Fig. 5). Here the kindofyear-roundbarrierexists.(Thisbarrieris,
continental shelfisverynarrow,which probably of course, only partial; there are many species
inhibits coast-wise migration of penaeids. The common to both subregions.) The western end
Banda and Aru Basins are fed by southerly in- ofNew Guinea isgeographically complex, with
flowsfromthe PacificOcean andthiswaterthen mountain ranges from 1000 m to over 4000 m
flows southwesterly through the Timor Trench high. Winds originating in the north-northwest
(Van Aken et al, 1988; Postma and Mook, and flowing across the neck of New Guinea
1988). Thus the net flow of intermediate and (about 1000 m high), could be deflected by the
deepwateristowardsthe Indian Ocean. In addi- much higher mountains in the east, resulting in
tion, from April to October the southeasterly local southerly, or even south-westerly winds
trade winds produce a northwesterly shallow- crossing the south coast. Such winds would
water flow, which appears to cause upwelling probably be cool and could produce further in-
and lower water temperatures (Fleminger, shore upwelling. Also, Fleminger (1986) re-
1986). This cold water then joins the surface viewed evidence that, during the Pleistocene
currents flowing to the northwest, carrying any glaciation,watertemperaturesinthisregionmay
penaeid larvae away from the extensive shallow have been unusually cool for the tropics, due to
coastal regions of southern New Guinea and cool prevailing winds and upwelling; this cool-
Australia. ing may have acted as a barrier to tropical
TheeffectsoftheNovember-March monsoon stenotherms. Dall et al. (1990) point out that
season on shallow-water movements do not ap- during the maximum ofthe Quaternary Glacial
pear to have been documented for this area. In Period the lowered sea levels would have re-
open waters the winds tend to be northwesterly sulted in most of the sea between New Guinea
during this period, which would enhance migra- and Australia becoming dry land. There would
tionofpenaeid larvaetowardsAustralia. Butthe havebeenasteepcoast,withvirtuallynoshallow
.
48 MEMOIRS OFTHE QUEENSLAND MUSEUM
TABLE4. Apparentsiblingspecies in the temperate subregionsofsouthern continentsand their
morewidely-ranging, usually tropical 'parent' species.
Subregion Sibling species Parent species
Southeast South America Penaeuspaulensis ?P.aztecus
South Africa Metapenaeopsisscotti 1M.philippii
SouthwestAustralia M. insona M. quinquedentata
M.fusca M. barbata
M. lindae ?Af acclivis
.
SoutheastAustralia M. insona .Vf. quinquedentata
M
etapenaeusbennettae M, moxebi
Penaeusplebejus P. latisulcatus
water, connecting the two subregions, probably 1 Extinction processes(eitherat low latitudes
eliminating the migration of shallow-water or ofNorthern Hemisphere counterparts).
penaeids during the last glacial period. The mi- 2. Evolution oflong indigenous taxa.
gration of penaeids towards the northern Unlike barnacles, the Penaeidae have a very
Australian area from Indonesia, appears, there- poorfossilrecordandextinctionhypothesescan-
fore, to have been restricted since the Pleisto- not be tested, but as a predominantly tropical
cene. group, extinction within the tropics is probably
ThenorthwestcoastofAustralia,whichisarid, less likely than in more widely ranging groups.
with hypersaline inshore waters also appears to There do not appear to be any clearexamples of
be unfavourable to penaeid colonisation. Of 36 amphitropicality in the Penaeidae. There are
shallow-water species in northern and north- Northern or Southern Hemisphere endemicspe-
eastern Australia, only 18 also occur in the far cies, but no matching pairs of species, nor are
northwest ofthe continent. there any species with a clear break in distribu-
tion in the tropics.P. aztecusandP.paulensis in
SOUTHERN HEMISPHERE ENDEMISM IN the Western Atlantic may be amphitropical spe-
THEPENAEIDAE cies, but the affinities of the Western Atlantic
complex of grooved Penaeus species needs
The Northern Hemisphere has only one sub- further research. Metapenaeopsis acclivis and
region (the Sino-Japanese) outside the tropics M. lindae in the Indo-West Pacific may also be
that includes endemic species, whereas in the amphitropical, but there arc significant morpho-
Southern Hemisphere the South African, South- logical differencesbetween them and thisgenus
west Australian, Southeast Australian and the also needs further research. The most usual sit-
Southeast South American Subregions all con- uation is for a northern or southern endemic to
tainendemicspecies(Tables2,3).Someofthese have a closely related species, which could be a
are closely similar to more widely distributed parent, in the adjacent tropics (Table 4).
tropical species and may be sibling species TheuniquenessofMacropetasmaandArteme-
(Table 4), but there are also three Southern siasuggeststhattheycouldberelictspeciesfrom
Hemispherespecieswhich donothaveanyclose much more widely ranging populations. Dall et
affinities. Metapenaeus macleayi in Southeast al. (1990)examinethepossibilitythattheycould
Australiaisdistinctivewithin itsgenus,butMac- be Gondwana relicts, but find this hypothesis to
ropetasma africanus in South Africa and Ar- be untenable. Macropetasma is unique among
temesia longinaris in Southeast South America the Penaeidae in possessing photophores; Ar-
are more exceptional. Both arc monospecific temesia superficially resembles some deep-
genera, they are quitedifferentfrom one another water Penaeoidea. Thus they could be relicts of
and from other genera, both fossil and present, a deep-water, possibly amphitropical group, but
of the Penaeidae. Artemesia and, to a lesser there are no similar extant deep-sea genera to
extentMacropetasmainhabitwaterscoolerthan supportthishypothesisandwholesaleextinction
is usual for the Penaeidae. would need to be invoked. Alternatively, they
Newman and Foster (1987) conclude that en- could have been once widely distributed in the
demism of barnacles in the Southern Hemi- cooler conditions of the Miocene and sub-
sphere is due to: sequently became extinct in the tropics (Valen-