Coral reef fishes

Tropical Marine Ecology: A case study at the Maldives,
Magoodhoo, Faafu Atoll
Introduction to the
main fish families in
reefs:
field identification
and ecology
Davide Seveso
Coral reef fishes are fishes which live amongst or in close relation to coral reefs
• Coral reefs fishes are the result of millions of years of coevolution among
corals, invertebrates and algae
• Coral reefs occupy less than 1% of the surface area of the world oceans, yet
they provide a home for 25 % of all marine fish species
~ 7.000 species (belonging to 75
families) occur on coral reefs or
nearby inshore habitats
Indo-Pacific region
~ 5000 species
Caribbean region
~ 2000 species
1. Acanthuridae – surgeonfishes
•
Compressed body structure laterally
•
Both the dorsal and anal fins are large, extending for most of the length of the body
•
Herbivorous or planktivores
dorsal fin
One o two spines on either side of the tail
anal fin
Eyes place at the high side of the body
Acanthurus xanthopterus
Acanthurus leucosternon
The small mouths have a single
row of teeth used principally for
grazing on microalgae or algal turf
Some genera use the small mouths
for nibbling and scraping small
organisms from the rocks and coral
Some genera are detritivors
Ctenochaetus striatus
Acanthurus triostegus
Acanthurus mata
Acanthurus japonicus
Dorsal and anal fins
are more wide
Mouth more
elongated to feed on
macroalgae
Zebrasoma veliferum
Zebrasoma flavescens
Naso unicornis
Naso brevirostris
Naso unicornis
Naso hexacanthus
Naso vlamingi
2. Chaetodontidae – butterflyfishes
• Small fishes (12 to 22 cm), very coloured, discoidal form
• Compressed body
• Little and elongated mouth with small brush teeth. The mouth can be protracted
• Benthic invertebrates feeders or planktivores
• Territorial corallivores
• Generally diurnal
uninterrupted dorsal fin
tail fin may be rounded or truncated
Chaetodon auriga
Chelmon rostratus
Chaetodon baronessa
eyespots on their flanks
dark bands across their eyes
Chaetodon unimaculatus,
Chaetodon bennetti
Chaetodon austriacus
They live in pairs formed by male and female
They are monogamous fishes
Chaetodon semilarvatus
Chaetodon ephippium
Haeniochus monoceros
Haeniochus diphreutes
Chaetodon baronessa
Chelmon rostratus
3. Scaridae - parrotfishes
• Medium size between 40 - 50 cm (maximum size 120 cm)
• Their numerous teeth are arranged in a tightly packed mosaic forming a parrot-like
beak
• Principally herbivourus (feed algal turf over dead corals)
• Some species include coral polyps in their diet.
large pectoral fins
The body is deep, narrow and lengthened
large and thick cycloid scales
Chlorurus bleekeri
3. Scaridae - parrotfishes
• Medium size between 40 - 50 cm (maximum size 120 cm)
• Their numerous teeth are arranged in a tightly packed mosaic forming a parrot-like
beak
• Principally herbivourus (feed algal turf over dead corals)
• Some species include coral polyps in their diet.
Parrotfishes play a significant role in bioerosion
They are the most important grazer organisms in coral reef
• Ecologically important as grazers
– reduce macroalgal cover
– maintain coral cover
• Ecologically important as bioeroders
On the Hawaiian reef
S. rubroviolaceus (45–54 cm size)
bioeroding up to 380±67 kg/indiv/year
On the red sea reef
S. niger exhibited the highest feeding rate
(98.9 bites/5 min), followed by C. sordidus
(76.5 bites/min)
But, the
average bite
volumes of C.
sordidus was
high
(0.110 cm3),
whereas S.
niger had low
average value
(0.002 cm3).
Scarus rubroviolaceus
Chlorurus sordidus
Scarus niger
Chlorurus sordidus Juv.
Chlorurus sordidus Ad.
• Sequential hermaphrodites starting as females and then changing to males
• In most parrotfish species, juveniles have a different color pattern than adults
A number of parrotfish species excrete a
mucus protective cocoon during the
night
Presumably it hides parrotfishes scents
from predators
4. Labridae – wrasses
• One of the largest and most diverse families of marine fishes(500 species in 60
genera)
• Tapering body, single dorsal fin running most of the length of the back. Swimming by
pectoral fins.
• Great diet variety: planktivores, piscivores, feed on invertebrates
Haliochoeres hortulanus
Protractile mouth and
thicks lips
Juveniles have a different color pattern than adults. There is also an intermediate phase
Wrasse are sexually dimorphic
Many species are capable of changing sex.
Juv.
Adult -femaleCoris gaimard
Intermediate
Adult -male-
Labroides dimidiatus, L. pectoralis
Cheilinus undulatus
Cheilio inermis
Macropharingodon meleagris
Novaculichthys taeniourus, IP e TP
Gomphosus varius
Epibulus insidiator
Cheilinus fasciatus
Labroides dimidiatus, L. pectoralis
5. Pomacentridae - damselfishes, anemonefishes
• One of the most abundant group of coral reef fishes
• Laterally-compressed fishes, small size
• Many species are highly territorial herbivores
omnivores forming small groups
planktivores forming large groups
•Uova bentoniche sorvegliate dal maschio.
Anal fin with two spines
Single and continuos dorsal fin
small- to medium-sized scales
Small and terminal mouth
Plectroglyphidodon lacrimatum
Territorial herbivores : they occupe and defend a portion of the reef, often centred
around an area of shelter.
By keeping away other species of fish, some pomacentrids
encourage the growth of thick mats of algae within their
territories
Pomacentrids forming school: in general, the coral is used as shelter, and many
species can only survive in its presence.
Chromis atripectoralis -planktivores
Neoglyphidodon Abudefduf
nigroris - onnivore
sexfasciatus-planktivores
Pomacentrus auriventris - onnivore
Chromis atripectoralis -planktivores
Neoglyphidodon nigroris - onnivoro
Dascyllus aruanus - planktivores
Dascyllus trimaculatus- planktivores
Plectroglyphidodon leucozonus - erbivoro
territoriale aggressivo
Amphiprion ocellaris
Amphiprion clarkii
6. Pomacanthidae - angelfishes
• Small-medium size, laterally compressed body
• Small mouth, relatively large pectoral fins and rounded to lunate tail fins
• Present vibrant colours
• Feed on benthic invertebrates, sponges, tunicates, bryozoans. Some species are
planktivores or territorial herbivores (filamentous algae)
Angelfishes have streamer-like extensions of the soft
dorsal and anal fins
Angelfishes are distinguished from
butterflyfish by the presence of strong
preopercle spines
Pomacanthus navarchus
• Some species are solitary in nature and form highly territorial mated pairs
• Others species form harems with a single male dominant over several females
• Angelfish species are known to be protogynous hermaphrodites. This means
that if the dominant male of a harem is removed, a female will turn into a
functional male.
Common to many species is a dramatic shift in
coloration associated with maturity.
Pomacanthus imperator, adult – intermediate – juvenile
7. Holocentridae – squirrelfishes, soldierfish
• Medium size
• Red and silvery colours dominate
• Large and thick cycloid scales, big mouth
• Feed on small fishes and benthic invertebrates. Some species planktivores
Short dorsal and anal fins
Tail fin with
two spines
Being
largely
or
entirely
nocturnal, they have relatively
large eyes
Myripristis kuntee
Sargocentron caudimaculatum
Spines on their gill covers
Sargocentron violaceum
Priacanthidae (bigeyes). Famiglia affine ai precedenti come aspetto, sovente
confusa.
• occhi e bocca grandi, scaglie piccole.
• piscivori o planctivori notturni
• colore rosso
Priacanthus blochii
Priacanthus hamrur
8. Mullidae - goatfishes
•Their bodies are deep and elongate with forked tail fins.
• By day form large inactive schools. by night the schools disperse and individual
goatfish feed
two separated dorsal fins
Goatfish are benthic feeders, using
a pair of long chemosensory
barbels to rifle through the
sediments in search of a meal. Like
goats, they seek anything edible;
worms, crustaceans, molluscs and
other small invertebrates are
staples.
Mulloidichthys vanicolensis
9. Serranidae - groupers, basslets
• Spindle-shaped body with single and continuos dorsal fin
• Many species are protogynous hermaphrodites, meaning that they start out as
females and change sex to male later in life
Pseudanthias tuka
Cephalopholis argus
Subfamily Anthiinae (basslets or anthias):
• Little and coloured body (pink, yellow, red)
• Planktivores (mainly zooplankton feeders)
• They form complex social structures based on the number of males and females
“Harems“: these consist of one dominant, colorful male, anywhere from 2-12
females and up to 2 'subdominant' males, often less brightly colored and nonterritorial.
Pseudanthias tuka
Pseudanthias dispar
Pseudanthias tuka
Subfamily Epinephelinae (groupers):
• Robust in form, with large mouths and small spines on the gill coverings
• They can be quite large, and lengths over a meter and weights up to 100 kg are
not uncommon
• Canine - like teeth
• Feed on fishes and crustaceans
•They are typically ambush predators, hiding in cover on the reef and darting out to
grab passing prey
Epinephelus tauvina
10. Aemulidae – grunts or sweetlips
• Medium-size Maximum length about 60 cm
• Dorsal fin continuous, small mouth with thick lips
• Adults are typically inactive during day
• Nocturnal bottom-feeding predators
Grunts, for their
ability to produce
sound by grinding
their teeth
Plectorhinchus lineatus e P. polytaenia
Plectorhinchus
chaetodonoides,
juv. and adult
Plectorhinchus
gaterinus,
juv. and adult
Plectorhinchus orientalis
….OTHER FAMILIES…..
Carangidae
• Fast-swimming predatory fishes that hunt in the waters
above reefs and in the open sea
• Streamlined body, with two separate dorsal fins, and a forked
tail
• They have a series of scutes or comb-like scales along the
caudal peduncle
Caranx sexfasciatus
Carangoides oblungus juv. con Parupeneus heptacanthus (Mullidae)
Carangoides bajad
Caranx melampygus
Apogonidae
•They are generally small fish, with most species being less than 10 centimetres
• Large mouths, dorsal fin divided into two separate fins
• They are nocturnal, spending the day in dark crevices within the reef
At
least
some
species brood the
eggs
inside
the
mouth of the males.
Cheilodipterus quinquelineatus
Apogon chrysotaenia
Apogon semilineatus
Pterapogon kauderni
Zanclidae – Only one species Zanclus cornutus, Moorish idol.
• Compressed and disk-like bodies, with black, white and yellow bands
• A number of butterflyfishes closely resemble the moorish idol
• Have small terminal mouth at the end of long, tubular snout
• Sponges, tunicates and other benthic invertebrates constitute the bulk of the
moorish idol's diet.
Balistidae - triggerfishes
• Small but strong- jawed mouth with teeth adapted for crushing shells
• The eyes are small, set far back from the mouth, at the top of the head
• The anterior dorsals fins are reduced to a set of three spines. All three are
normally retracted into a groove
• The ventral and the posterior dorsal fins are capable of undulating from side to
side to provide slow speed movement.
As a protection against
predators, triggerfish can
erect the first two dorsal
spines: The first spine is
locked in place by erection of
the short second spine, and
can be unlocked only by
depressing the second,
“trigger” spine.
Hence the family name
“triggerfish”.
Balistoides viridescens
Balistoides conspicillum
Pseudoalistes flavimarginatus
Sufflamen freanatus
Balistapus undulatus
Lutjanidae - snappers
• Medium - big size ( some species can grow to about a meter in length)
• 1 dorsal fin , canine - like teeth.
• Most feed on crustaceans or other fish
Some little
species forms
schools and
additionally feed
on zooplankton
Lutjanus quinquelineatus
Macolor macularis
Lutjanus lutjanus e Macolor macularis
Lutjanus argentimaculatus
Siganidae – pesci coniglio
• Forma ovale, compressa, spine velenose, bocca piccola terminale con denti
incisiviformi. 1 pinna dorsale.
• Erbivori
• Importanti come cibo
Siganus vulpinus
Siganus guttatus
Lethrinidae – pesci imperatore
• Medio-grandi, simili ai Lutianidi, colore di solito argenteo.
• Predatori notturni di invertebrati mobili o pesci.
• Importanti per la pesca
Lethrinus olivaceus
Lethrinus obsoletus
Monotaxis grandoculis
Monacanthidae – pesci lima
• Simili ai balistidi, più compressi, più piccoli, dorsale più delicata.
• Mangiatori di invertebrati bentonici sessili
• Nuoto come i balistidi
Rudarius minutus
Oxymonacanthus longirostris
Chaetoderma penicilligera
Aluteres scriptus
Ostraciidae – pesci scatola
• Carapace di piastre ossee che formano corpo esagonale, bocca piccola
• Mangiatori di invertebrati sessili
• Nuoto con pinne dorsale e anale
• Uova pelagiche
• Secrezione
tossica
Ostracion cubicus
Lactoria fornasini
Ostracion meleagris
Lactoria fornasini
Tetraodontidae – pesci palla
• Corpo globoso, pelle nuda, bocca piccola con denti fusi in 4 piastre.
• Capaci di gonfiarsi
• Accumulo di sostanze tossiche (tetrodotossina)
• Nuoto con pinne D e A
• Mangiatori di invertebrati bentonici
• Uova bentoniche
Canthigaster valentini
Arothron mappa
Arothron caeruleopunctatus
Canthigaster papua
Arothron nigropunctatus
Arothron stellatus
Diodontidae – pesci istrice
• Simili ai tetraodontidi, ma con spine erettili, occhi più grandi, denti in 2 piastre.
• Mangiatori di invertebrati bentonici
• Uova pelagiche
Cychlychthys orbicularis
Diodon liturosus
Blenniidae (bavose, blenni)
• piccoli, allungati, senza scaglie, 1 dorsale continua.
• bentonici territoriali
• 2 sottofamiglie: blenniinae (dai denti a sciabola), carnivori, e Salariinae
(dai denti a pettine), erbivori.
• uova bentoniche
Ecsenius axelrodi
Plagiotremus rhinorhynchus
Meiacanthus grammistes, maschio con uova
Aspidontus taeniatus, imita
Labroides dimidiatus (sotto,
labride pulitore) per avvicinare
pesci più grossi e mordere pinne
o scaglie. Mimetismo aggressivo.
Ecsenius yaeyamaensis
Gobidae – ghiozzi
• La famiglia di pesci più numerosa.
• Piccoli, allungati, bocca grande con denti conici, 2 pinne dorsali, ventrali fuse
assieme in un disco. Bentonici.
• Uova bentoniche guardate dal maschio.
Bryaninops yongei
Amblyeleotris randalli
Cryptocentrus cinctus
Amblyeleotris sp. e Ptereleotris hanae
Bryaninops natans
Pleurosicya mossambica sul nido
Nemateleotris decora (Microdesmidae)
Caesionidae (fucilieri)
• corpo fusiforme, 1 pinna dorsale, bocca piccola protrusibile.
• planctivori in banco, buoni nuotatori.
• Importante risorsa alieutica in certe aree.
Caesio teres
Caesio lunaris
Ephippidae (pesci pipistrello),
Platax teira
Cirrithidae (pesci falco)
Paracirrhites forsteri
Cirrhitus pinnulatus
Oxycirrhytes typus
Scorpaenidae
La femmina produce uova
che vengono depositate
sulla parte dorsale finale
del maschio che le feconda
e le incuba nel suo corpo
Syngnathidae Hippocampus histrix
Corythoichthys haematopterus
Solenostomidae
Synodontidae
Fish Belt Transect
5 meters
5 meters
transect