Download THE FISH

11
THE
FISH
Introduction
Ninety species of fish have been recorded in the Reserve (table 2).
These are contained in 14 orders and 48 families.
The largest
order,
the perciform or perch-like fishes consists of 60 species, 66% of the
total number of fish.
The largest families are the Tripterygiidae and
Labridae, the former with 13 species and the latter with 7 species
occurring in the Reserve.
A few families, the Gobieosocidae, Gadidae,
Syngnathidae, Serranidae, Carangidae, Kyphosidae and Pomacentridae
contain between 3 and 5 species; however, the majority are represented
by 1 or 2 species only.
The most abundant fish in the Reserve are the small benthic
tripterygiids, Forsterygion varium, Notoclinops segmentation and
Gilloblennius tripennis; the midwater plankitvore,
(bigeyes) and the goatfish, Upeneichthys porosus.
in descending order of abundance, are:
Pempheris adspersa
The other common fish,
sweep (Scorpis aequipinnis) ,
paketi (Pseudolabrus celidotus) , snapper (Chrysophrys auratus),
leatherjackets (Parika scaber), blue maomao (Scorpis violaceus) , hiwihiwi
(Chironemus marmoratus), red moki (Cheilodactylus spectabilis) , parore
(Girella tricuspidata), blue cod (Parapercis colias) and banded wrasse
(Pseudolabrus fucicola) .
Notes on classification and naming
The fishes of the world are separated into three major divisions
or classes:
lampreys;
The jawless fishes, class Agnatha, including the hagfish and
the cartilaginous fishes, class Chondrichthys and the bony
fishes, class Osteichthys.
Reserve.
Only the Agnatha are not represented in the
Within these divisions fish with similar anatomical
characteristics are classified into orders ( -formes endings), which are
then further divided into suborders and families ( -idae endings).
The
arrangement of orders and families used here follows those used by
Midgalski & Fichter (1976) for the cartilaginous fishes and Greenwood et
al. (1966) for the bony fishes.
12
Each species is then given a scientific name consisting of two
parts.
The first designates the genus to which the fish belongs.
with the same genus name have certain features in common.
the species name distinguishes one species from any other.
Fish
The second,
The scientific
name is important as many species have assorted common names which
usually vary depending on the locality in which they were found.
For
example, the banded wrasse, Pseudolabrus fucioola is also known as the
chinaman or kelpfish in other parts of New Zealand and as the„purple
wrasse in Australia.
The common name 1kelpfish1 can also refer to other
species such as Chironemus marmoratus (hiwihiwi) and Odax pullus
(butterfish).
Since several species.have been described more than once and under
different names in the past, the author of the correct name, or the
scientific name currently in use, is often indicated.
Thus the
1
authority1
appears directly after the species name, unpunctuated if it retains the
original genus and bracketed if the fish was originally described in
another genus.
Many fish in New Zealand are only relatively recent
discoveries and have yet to be officially described.
Usually these are
nominally assigned to a genus but are given no species name, e.g. the
lizardfish, Synodus sp.
Where there are several undescribed species all
belonging to the same genus the different species are distinguished by
numbers or letters of the alphabet, e.g. the undescribed tripterygiids
are listed here as Forsterygion sp. A.to F.sp.F .
When listing several
species of the same genus, or when mentioning the same species several
times it is common practice to abbreviate the genus name to the first
one or two letters.
Several structural characters are used
: to classify fish into
their various groupings.
Neccessarily these are constant within a species
but vary between species.
They include the number, positioning and shape
of the fins;
the number of spiny and soft rays supporting each fin; the
number and shape of the lateral line(s);
the number of pored lateral
line scales; the presence or absence of scales, their arrangements and
the types of scales found on various parts of the fish's body; variations
in the structure of skeletal components such as the jaws, vertebrae,
gill arches and opercula; the number, structure and positioning of the
teeth and gill rakers and the possession of species appendages such as
sensory feelers and protective spines.
13
Format
DESCRIPTIONS:
Each fish is introduced by its scientific name and accepted New
Zealand common names.
The scientific name, especially the species name
is often selected to indicate some peculiarity of the structure, habit
or habitat of .the fish designated.
Its derivation is indicated where it
is known.
The general appearance, body shape and colour is described for each
fish.
Other distinguishing features such as the number, structure,
positioning, shape and size of the fins; the relative sizes of the head,
mouth and eyes and the presence of any special protective or sensory
structures are also described.
Detils of size are usually given as the maximum length recorded
for the species and the average size range which would be observed if
diving in north eastern New Zealand coastal waters.
All length measurements
refer to the total length of the fish, i.e. the distance from the tip of
the snout to the tip of the tail.
or metres.
Lengths are presented in millimetres
Average or maximum weights are also given as a measure of size
where the information is available.
These are indicated in grams or
kilograms.
Each fish is illustrated with a black and white line drawing.
The
maximum size and a scale are also presented, the scale being adjusted to
the average size of the fish.
Along with the illustration the fin formula
(the characteristic number of spines and rays in each fin) and the number
of pored lateral line scales are presented for each fish where known. The
notation used can be explained using the goatfish as an example:
D.viii. i.8;
A.ii.6;
represent the fins:
C = caudal.
V.i.5;
P.15-16;
C.15;
L.l. 28-30.
The letters
D = dorsal, A = anal, V = ventral, P = pectoral,
Roman numerals are used to indicate the number of spines and
arabic numerals to indicate the number of soft rays in each fin.
L.l.
refers to the number of lateral line scales. Therefore, goatfish have two
dorsal fins, the first composed of 8 spines and the second of 1 spine
and 8 soft rays.
ventral fin
The anal fin consists of 2 spines and 6 rays.
Each
has one spinous and five soft rays and each pelvic fin has
15 or 16 rays.
The caudal fin is supported by 15 rays and the number of
pored scales forming the lateral line may vary between 28 and 30.
14
Various aspects of the mode of life and behaviour of each species
can aid in field identification.
Thus, the characteristic activity period
of each fish (i.e. whether the fish is active at night or day) and the
typical mode of locomotion are described.
An indication of where the fish
are most likely to be found and their social organisation is also given,
i.e. whether the fish are most likely to be found at the water surface, in
midwater, close to the bottom or resting on the bottom and whether they
form schools, aggregations or are solitary.
the size of the group and whether
Information is provided on
the fish range widely over the reef
or are site attached with a more restricted movement range.
DISTRIBUTION:
The distribution of each species is described in a series of
progressively narrowing scales.
Firstly distribution is described in
general as to where the species
has been recorded in the world, and then
where it is found around New Zealand.
An indication of the relative
abundances around the New Zealand coast are given where possible.
All New
Zealand place names referred to in the text are indicated in figure 1.
Local distribution patterns describe where the fish is found in
the Reserve.
Again abundances are also indicated.
For many of the
reef associated species estimates of the numbers of fish found in the
different subtidal habitat types are available.
These were obtained by
counting fish along five transect lines in each habitat.
p
Moderate to
large fish were counted in 50 x 10m transects, whereas 25 x 4m transects
were used for the smaller benthic species.
The numbers of each species
in a habitat were averaged to obtain an estimate of the density present.
These densities
are expressed here as the average number of fish per
hectare.
The distribution and abundance patterns around New Zealand and
within the Reserve are illustrated.
Seasonal differences are indicated
where appropriate by a dashed line.
FEEDING:
The diet and foraging habits of each fish are briefly described.
Structural adaptations for finding, catching and consuming prey are also
noted.
These include sensory feelers, lures and the structure of the teeth
and jaws.
A more detailed composition of the diet is diagrammatically
represented.
This information was obtained mainly from fish taken from
15
from the Reserve and adjacent coastal waters.
Samples of fish which are
rare in the Reserve were obtained form the Poor Knights Islands.
LIFE HISTORY:
Several aspects of the life cycle are considered:
(i)
Age and growth - the maximum age recorded for a particular species
is given along with an indication of their growth rate.
The latter is
best illustrated by the size reached at the end of the first year after
settlement and/or the size and age at which the fish reach maturity.
This allows for comparisons of growth rates between species and between
different populations of the same species.
(ii)
Reproduction - the timing of the breeding season, the mode of
reproduction and spawning behaviour are described where these are known.
The occurrence of parental care is also noted.
Where spawning observations
are lacking the breeding season is estimated by the presence of ripe gonads,
observations of courting behaviour, the presence of eggs and the timing
of juvenile settlement.
(iii)
Eggs and development - the eggs are described with respect to
size, structure and whether they are demersal or pelagic.
Notes on
embryonic and larval development are provided where these are available.
(iv)
Juvenile settlement - the recruitment period, the size of newly
settles juveniles and the habitats in which they are found
are described.
Any differences from adult fish in colour, structure, behaviour or
distribution are also discussed. •
The seasonal aspects of breeding, presence of eggs in the plankton
and juvenile settlement are illustrated.
Question marks are used to
indicate that the extent of the breeding season is uncertain.
16
Table 2:
A list of the fish species recorded in the Cape Rodney to
Okakari Point Marine Reserve.
The scientific name, authority
and accepted common names of each fish are presented along
with and indication of relative abundances and the quality
of information available for each species.
KEY
Relative abundance
Field guide
•
abundant
>10 individuals or >2 schools on all dives
O
common
5-10 individuals or
O
frequent
1-5
individuals or 1-2 schools on most dives
v
occasional 1-5
individuals or 1-2 schools on some dives
R
rare
s
seasonally present
2 schools on most dives
only a few sightings ever recorded
Quality of information available
***
good local knowledge - detailed studies in the Reserve or
north east New Zealand
**
good New Zealand knowledge or preliminary local knowledge
*
'
little New Zealand knowledge, some information from studies
elsewhere in the world
- .
little information available
Abbreviations
B & S = Bloch & Schneider
C & V = Cuvier & Valenciennes
M & P = McCulloch & Phillips
Class Chondrichthys
Subclass Elasmobranchii
ORDER:
Squaliformes
Family Carcharhinidae
Carcharinus hrachyurus (Gunther) bronze whaler shark
R -
Family Sphyrnidae
Sphyrna zygaena (Linnaeus)
hammerhead shark
R -
17
Family Isuridae
Isurus oxyrinchus Rafinesque
ORDER:
mako shark
Rajiformes
Family Dasyatidae
Dasyatis brevieaudatus (Hutton)
short-tail stingray
Dasyatis theditis (Waite)
long-tail stingray
Family Myliobatidae
Myliobatis tenuicaudatus (Hector) eagle ray
Family Torpedinidae
Torpedo fairohildi (Hutton)
electric ray
Class Osteichthys
Subclass Actinopterygii
Superorder Teleostei
ORDER:
Anguillliformes
Suborder Anguilloidei
Family Muraenidae
Gymnothorax prasinus (Richardson) yellow moray eel
Family Congridae
Conger wilsoni (B & S)
conger eel
Family Ophichthidae
Ophisurus serpens (Linnaeus)
ORDER:
snake eel
Clupeiformes
Family Clupeidae
Sccrdinops neopilohardus (Steindacher) pilchard
Family Engraulidae
Engraulis australis (White)
ORDER:
anchovy
S almoni formes
Suborder Myctophoidei
Family Synodontidae
Synodus sp.
ORDER:
lizardfish
Gobieosociformes
Family Gobieosocidae
Diplocrepis puniceus (Richardson) suckerfish
18
Tracheloschismus pinnulatus (B & S) lumpfish
Tracheloschismus melobesia(Phillips) barred clingfish
ORDER:
dellichthys morelandi Briggs
painted clingfish
Gastrocyathus gracilis Briggs
slender clingfish
Gadiformes
Suborder Gadoidei
Family Gadidae
Physiculus bacjius (B & S)
red cod
Physiculus breviusculus(Richardson) bastard red cod
Lotella rhacinus (Richardson)
ORDER:
rock cod
Antheriniformes
Suborder Exocoetoidei
Family Exocoetidae
Eeporhampus ihi(Phillips)
ORDER:
piper
Berycifoi
Suborder Berycoidei
Family Trachichthidae
Hoplosthethus elongatus(Gunther)
slender roughy
Family Berycidae
Trachichthodes affinis(Gunther)
ORDER:
golden snapper
Zeifoi
Family Zeidae
Zeus faber Linnaeus
ORDER:
john dory
Gasterosteiformes
Suborder Syngnathoidei
Family Syngnathidae
Lissocampus filum (Gunther)
short-snouted pipefish
Stigmatopora macropterygia Dumeril long-snouted pipefish
Hippocampus abdominalis(Lesson)
ORDER:
seahorse
Scorpaenifoi
Suborder Scorpaenoidei
N
Family Scorpaenidae
Scorpaena cardinalis Richardson
red scorpio.nfish
19
Family Trigilidae
red gurnard
Chelodonichthys kumu (Lesson)
ORDER:
Percifc
Suborder Percoidei
Family Serranidae
Ellerkeldia huntii (Hector)
redbanded perch
v **
Caesioperca lepidoptera (B&S)
butterfly perch
O *
R -
Caprodon longimanus (Gunther)
splendid perch
Callanthias allporti Gunther
Family
Acanthoclinidae
Acanthoclinus quadridactylus (B&S) rockfish
Family
Carangidae
Seriola grandis Castlenau
kingfish
Caranx geovgianus Cuvier
trevally
O *
s
O **
s
Decapterus koheru (Hector)
koheru
#
Trachurus novaezelandiae Richardson
Family.
(B&S)
snapper
• ***
goatfish
• **
bigeye
• ***
(B&S)
Mullidae
Pempheridae
Pempheris adspersa Griffin
Family
Kyphosidae
Girella tricuspidata (Qiioy & Gaimard)
parore
• **
V -
Kyphosus sydneyanus (Gunther)
Family
* *
kahawai
Upeneichthys porosus (C & v)
Family
m
*
Sparidae
Chrysophrys auratus
Family
horse mackerel
s
Arripidae
Arripis trutta
Family
• **
Scorpis aequipinnis Richardson
sweep
• **,*
Scorpis violaceus (Hutton)
blue maomao
• ***
R -
Pentacerotidae
Paristiopterus labiosus (Gunther)
giant boarfish
Zanclistius elevatus (Ramsay & Ogi'lby) long-finned boarfish R Family
Family
Pomacentridae
Parma alboscapularis
black angelfish
R -
Chromis dispilus Griffin
two-spot demoiselle
o ***
Chromis hypsilepis(Guenther)
single-spot demoiselle
R -
hiwihiwi
•
Chironemidae
Chironemus marmoratus (Gunther)
20
Family Aplodactylidae
Aplodactylus meandratus Richardson marblefish
v # **
Family Cheilodactylidae
Cheilodactylus spectabilis Hutton
red moki
Cheilodactylus douglasi
porae
v **
Cheilodactylus macropterus(B & S)
tarakihi
R **
blue moki
R *
yellow-eyed mullet
v **
Pseudolabrus oelidotus (B & s)
paketi
• ***
Pseudolabrus fucicola (Richardson)
banded wrasse
O ***
• **
Pseudolabrus miles (B & s)
scarlet wrasse
Family Latridae
Latridopsis ciliaris (B & S)
Suborder Mugiloidei
Family Mugilidae
Aldrichetta forsteri(c & v)
Suborder Labroidei
Family Labridae
Pseudolabrus inscriptus(Richardson) green wrasse
v **
Pseudolabrus luculentus (Richardson) orange wrasse
v **
Bodiccnus occycephalus (Bleeker)
red pigfish
v **
Coris sandageri (Hector)
Sandager1s wrasse
v **
butterfish
o **
blue cod
O **
spotted stargazer
R -
crested blenny
O **
Family Odacidae
Odax pullus
Suborder Trachinoidei
Family Mugiloididae
Parapercis colias (B & s)
Family Ura'noscopidae
Genyagnus monopterygius (B & S)
Suborder Blennioidei
Family Blenniidae
Blennius laticlavius Griffin
mimic blenny
Plagiotrerrrus tapeinosoma (Bleeker)
R *
• ***
Family Tripterygiidae
Forsterygion varium(B & S)
mottled blenny
Forsterygion capito (Jenyns)
cobble blenny
m ***
21
Forsterygion sp.B
yellow-black blenny
v **
Forsterygion sp.C
oblique-swimming blenny
v
8
Forsterygion sp.D
Yaldwyn s blenny
v **
Forsterygion sp.E
scaly-headed blenny
v **
Forsterygion sp.F
chocolate blenny
v **
Gillohlennius tripennis
spectacled blenny
• **
Gillohlennius deoemdigitatus
threepenny •
v **
Eelcogramma sp.A
chequered blenny
V **
Eelcogramma sp.B
tiger blenny
V **
Notoclinops segmentation (M & P) banded blenny
v **
red topknot
v **
Ericentrus ruber{Button)
commmon weedfish
V *
Cristiceps aurantiacus
crested weedfish
hlotoclinus compressus (B & S)
Family Clinidae
Suborder Scombroidei
Family Gempylidae
Thrysites atun(Euphrasen)
snoek
R *
Family Scombridae
Scomber australasicus
ORDER:
common mackerel
Tetradontifoi
Suborder Balistoidei
Family Monacanthidae
Parika scaber(B & S)
leatherjacket
• ***
porcupinefish
V -
sunfish
R *
Suborder Tetradontoidei
Family Diodontidae
Allomycterus whitleyi Phillips
Family Molidae
Mo la mo la Linnaeus
22
CLASS
CHONDRICHTHYS
the cartilaginous
fishes
The fish belonging to this group, the sharks, skates, rays and
chimaeras, exhibit many similarities in their general body structure.
There is no true bone, the skeleton being composed entirely of cartilage.
These fish lack typical scales.
Instead, the skin is covered with
tooth-like dermal denticles, closely set to form a sandpaper-like surface
known as shagreen, which is extremely tough and difficult to penetrate.
They do not possess gill covers.
With few
open out on each side of the body.
exceptions five gill slits
Most species have a spiracle near
each eye, through which they can 'breathe' while feeding or, as in the
case of the rays, when the mouth which is situated on the undersurface
is covered in sand or mud.
All these fish have a well developed lower
jaw with numerous teeth arranged in several series.
nictating membrane, or third eyelid, is present.
when present, are rigid
In some groups a
Dorsal fin spines,
and not erectile. Swim bladders are not found
in this group of fishes.
This class contains about 550 present day species.
characters illustrated).
23
ORDER SQUALIFORMES -
the sharks
In all there are about 225-250 species of sharks.
They are
predominantly marine fishes, although a few species run far upstream into
brackish and freshwater.
Most occur in the tropical and subtropical belt,
but some species are found in temperate and even polar waters.
Sharks
usually dwell in shallow waters; however a few species prefer depths of
several hundred metres 0
Sharks are typically cylindrical in form.
Most are large, powerful
and fast swimming; however, some species are extremely sluggish and rarely
move.
Size varies from 15-20m for the whale sharks down to about 0.5m for
the smallest shark species„
Without exception sharks are carnivorous, feeding primarily on smaller
fish.
Fast swimming sharks pursue and catch their prey.
species lie in wait for passing fish.
The more sluggish
These predaceous species have large
sharp teeth adapted for tearing and cutting.
Some of the smaller sharks,
which feed mainly on hard-shelled crustacea, have pavement-like crushing
teeth.
The teeth are not fixed into sockets like most fish, but are attached
to a band which is continually growing forwards.
The teeth at the rear are
in a recumbent position, moving forward and becoming upright and functional
as those in the front are shed.
Reproduction in the sharks takes place through internal fertilisation.
The males possess a pair of copulatory organs, the claspers, which are
located on the inner edges of the pelvic fins.
transfer sperm to the female.
The claspers are used to
In most sharks development is ovoviviparous,
but in some species is oviparous or viviparous.
Compared with the teleost
fishes the number of young produced by sharks is small.
Three families of sharks are represented, each by one species, in the
Reserve.
Family
Carcharhinidae -
requiem
sharks
This is the largest shark family.
temperate seas throughout the world.
Its members inhabit tropical and
Their chief cahracteristig:s are:
There
are two dorsal fins, the second of which is smaller and is situated directly
opposite the anal fin;
the upper lobe of the tail fin is sickle-shaped and
2-3 times larger than the lower lobe;
the eyes possess a nictating membrane;
the spiracles are either much reduced in size or are lacking;
the teeth are
24
triangular and razor sharp.
These sharks are usually coloured drab brown
or grey.
The majority of species are harmless.
Family
Sphyrnidae -
hammerhead
sharks
The hammerhead sharks are easily distinguished from all other sharks
by the flattened head which is extended into hammer-like lobes on each side.
These swift swimming sharks occur in shallow, warm seas with some species
wandering into cooler regions as seas warm over the summer.
Family
Isuridae -
mackerel
sharks
These are medium to large, surface swimming sharks found in most seas
of the world.
Their bodies are torpedo-shaped and stoutly built, tapering
to a slender, depressed caudal peduncle which usually has a strong keel on
each side.
This lateral keel extends onto a large lunate tail fin.
first dorsal fin is large.
anal fin.
The
The second is small and is situated opposite the
The five gill slits are wide and are located in front of the
pectoral fin.
25
Familys
Carcharhirtus brachyurus -
bronze
Carcharhinidae
whaler
(Carcharhinus = jagged snout
brachyurus = short-tailed)
DESCRIPTION:
This shark is distinguished by its flattened snout, metallic
bronze colouration and the characteristic shape of the tail»
The first
The
dorsal fin is large and is situated in front of the ventral fins.
pectoral fins are relatively large»
and blade-like»
The mouth is large and the teeth small
There are five gill slits, the last of which is situated
above the base of the pectoral fin.
Small spiracles are present»
These fish grow to about 4m in length; however those sighted in the
Reserve are much smaller/ the largest being recorded at 2„75m.
Despite their large size, these sharks are generally shy.
Only one
unprovoked attack on man, by a bronze whaler, has been officially reported.
DISTRIBUTION s
Generals
C. brachyurus is found around Australia and in New
Zealand waters as far south as Cook Strait.
In New Zealand the bronze
whaler is only commonly seen during the summer when they appear to move into
shallower water, even entering the breaker zone of surf beaches.
FEEDING:
This species is an opportunistic predator, its food consisting
mainly of octopus and fish.
Little is known of its natural feeding habits.
Studies on related species have indicated that members of this genus feed on
healthy, free-moving animals and feeding is not limited to scavenging on the
dead and dying.
Observations made, in the Reserve, of feeding on speared fish have
shown that the bronze whaler is similar to other sharks in detection and
taking of food.
Initial attraction appeared to be in response to the
vibrations set up in the water by the struggling fisho
approached the bait
eating.
Usually, the shark
slowly and would 'sniff1 at it several times before •
Sometimes it would attack the fish with a fast rush and take it
immediately.
The prey was bitten and ripped apart with a sideways shaking
of the head.
LIFE HISTORY:
Little is known of the life history of these sharks.
Like the
other members of its family, this species is viviparous, i.e. the young are
born alive.
27
Family:
Isyrus ox^rmelhys -
mako,
Isuridae
blue pointer
(Isurus = equal-tailed)
DESCRIPTIONS
This sreamlined, active shark is blue or blue-grey above and
white underneath=
The two colours are sharply separated„
The body is
torpedo-shaped, with a pointed snout and a slender tail stalk which is
flattened from above and below„
the tail stalk*
There is a strong keel on either side of
The first of the two dorsal fins is large and the second
is small and situated opposite a similar sized anal fin*
Mako sharks can grow to lengths of 4o5m and weigh as much as 485kg=
The largest caught on rod and reel was taken off Mayor Island, New Zealand,
and weighed 482.5kg„
These are wide-ranging, solitary sharks usually found in surface
waters.
They are not generally regarded as being dangerous to man,
DISTRIBUTIONS
Generals
Zealand seas.
The mako occurs in Australian, South African and New
It is found around the entire New Zealand coastline but is
most common north of Cook Strait.
Locals
These fish are infrequent visitors to shallow coastal
waters and have only occasionally been reported in the.Reserve„
FEEDINGs
Io oxyrinchus is a voracious carnivore, feeding mainly on small
schooling fishes»
The teeth are small and awl-like and are well adapted
for seizing prey.
LIFE HISTORYs
Little information is available on age, growth and
reproduction in this species»
have grown to about 2m long*
Sexual maturity is attained when individuals
Mew Zealand distribution
29
Family:
jiplh^ma
zyganea
-
Sphyrinidae
hammerhead shark
(Sphyrna = a hammer
zygaena = a yoke)
DESCRIPTION:
The peculiar shape of the head immediately distinguishes
this species from other sharks which frequent New Zealand waters .
The front
portion of the head is flattened and extended into lobes, one on each side.
The eyes, situated at the end of each lobe are bluish and possess a brown
nictating membrane»
There are two dorsal fins.
The second, the smaller
of the two, is situated opposite the anal fin„ The upper lobe of the tail
is distinctly notched and is much longer than the lower lobe*
There are
five gill slits and the fourth and fifth sit over the base of the pectoral
fine
The triangular and pointed teeth are serrated in juvenile hammerheads
but have a smooth edge in' the adult fish*
Colouration ranges from pale grey to a dark brown dorsal surface
which fades to pale yellow on the belly.
Individuals can grow to 6.5m in length, with the 'hammer8 measuring
2m in. width.
Specimens up to 1«, 25m have been observed in the Reserve.
These sharks are usually considered dangerous«
DISTRIBUTION:
General:
Sozygaena ranges along the east coast of Australia
to Tasmania, the coast of Western Australia and in New Zealand as far south
as Cook Strait. It frequents both open oceans and shallow coastal bays.
Juveniles often ascend rivers to the end of their tidal influence.
Local:
rocky reefs.
The hammerhead shark is only an occasional visitor to
Small individuals have been sighted in the Reserve, usually
during the summer months.
FEEDING:
Members of this species feed predominantly on fish.
Mackerel
(Scaustralasieus) and other schooling fishes are taken by the younger, more
active hammerheads, while cruising in surface waters.
The older sharks
live mainly on stingrays„
LIFE HISTORY:
The life history features of this species are poorly known.
The young are born alive.
A female about 3m long can produce up to 30 pups.
Sphyroa zygaen^
31
OlRDER RAJFORMIES
-
rays
aod skates
This order includes the sawfishes, guitarfishes, electric rays,
skates, stingrays, eagle rays and mantas.
recognised
Members of this group are easily
by their body form which is adapted to life on the sea floor.
The body is flattened dorso-ventrally and the large pectoral fins are joined
to the sides of the head and body,.. The five pairs of gill openings are
situated beneath the body disc and not on the sides of the head, as seen in
the sharks.
The spiracles, placed close behind the head, are very large to
enable the ray to 'breathe1 while lying on sand or mud.
are situated well back, or may be lacking altogether.
The dorsal fins
There is no anal fin.
In many species the tail is reduced to a whip-like appendage, without a tail
fin and often with one or more serrated spines at its base.
Species range in size from a few centimetres long to the giant manta
rays with a breadth of about 7m and weight of around 1500kg.
The Raj iformes are widely distributed fish in both latitude and depth.
They occur in the Atlantic, Pacific and Indian oceans.
marine
They are primarily
temperate fish, but several species have colonized freshwater rivers.
Most live on or near the bottom.
They usually swim slowly, staying close
to the bottom, although they are capable of rapid propulsion when neccessary.
Movement is usually achieved by undulations of the pectoral fins; however,
some species also use the tail and body muscles.
Skates and rays eat a variety of foods.
Some species prefer the
hard-shelled molluscs while others feed mainly on fish.
The large mantas
feed on planktonic organisms and small fish.
In this group reproduction occurs with internal fertilisation.
The
males possess a pair of claspers along the inner edges of their pelvic fins
in the same manner as the sharks.
The inner edges of the claspers have
grooves with overlapping edges, thus aiding transport of the sperm into the
female.
Development may be
oviparous - the eggs are laid encased in a
horny capsule, or ovoviviparous - the embryos develop within the female
and are extruded at the larval stage.
Three families of this group are represented in the Reserve.
32
Family Dasyatidae -
stingrays
The stingrays are best known for; their long, whip-like tails which
are armed with spines near the base.
The body disc is flat and wide.
Nearly 100 species of stingrays are distributed in warm shallow seas
throughout the world.
Stingrays generally lie on the bottom, buried in
sand or soft sediment.
They are usually mottled grey and brown on the
dorsal surface and are pale yellow on the ventral surface.
These fish
range in size from 0.3m to 2m in breadth.
The venomous spines present at the base of the tail can inflict a
severe wound.
The venom may have a paralyzing effect on humans, but is
rarely fatal.
Two species of stingray, Dasyatis brevicaudata and D,theditis are
found in New Zealand and in the Reserve.
Dotheditisr the long-tailed
stingray, is distinguished by possessing a much longer tail than the former
species.
However, little information is available on this species, hence
it is not considered here in detail.
Family
Mlyiiobafadae -
eagle
rays
The eagle rays are more pelagic than the stingrays, although they
still feed on the bottom.
Unlike the typical bottom-dwe11ing stingrays,
members of this group have a distinct head region.
The eyes and spiracles
are situated on each side rather than on the top of the head.
Most species
have one or more venomous spines at the base of the tail.
Eagle rays occur in warm seas throughout the world.
Only one species
is known in New Zealand and in the Reserve.
Family
Torpedioidae -
electric
rays
The body and pectoral fins of these rays form an almost circular disc.
The electric rays are characterized by a smooth, scaleless skin and by the
presence of two large electric organs, one on each side of the head.
They
can reach up to 1.5m in length and weigh around 100kg.
These fish are poor swimmers and spend most of their time partially
buried in sand and mud.
Some species live in shallow inshore waters while
others are blind and live at great depths.
Only one species occurs in the Reserve.
33
Family:
Das^atis bre^gcaydafos -
short-tailed
Dasyatidae
stingray
(brevicaudatus = short-tailed)
DESCRIPTION:
The disc in this species is almost quadrangular.
is long and whip-like and is-fairly thick at, the base.
The tail
This fish was
originally described from a mutilated specimen without a tail, hence the
species and common names.
There are no dorsal or caudal fins.
base of the tail there are two serrated spines.
Towards the
These spines have a groove
along which venom is conducted, from the venom glands at the base, to the
tip of the spine.
Colouration varies fron slate grey to brownish grey on
the back and is white on the underside.
This is the largest of our. common rays.
Short-tailed stingrays
caught in New Zealand waters have been recorded at 4.2m long and 2.1m wide.
These fish are usually found resting on the substratum.
swimmers.
They are poor
Movement is achieved by undulations of the large pectoral fins.
Both fins move in phase.
DISTRIBUTIONs
Generals
This species occurs around Australia and New Zealand.
In New Zealand they are found as far south as Otago, but are most common
around the North Island.
They usually inhabit sandy coastal areas to
depths of 100m, but often also venture into harbours and estuaries.
Locals
Dobrevicaudatus is occasionally found over rocky reefs
such as the Reserve.
FEEDINGs
Any available animal food is taken by these fish.
Their diet
consists mainly of shellfish and crabs, taken while foraging over open
sandy bottoms.
LIFE HISTORYs
Little information is available on the life history of the
short-tailed stingray.
Like other members of its family this species is
an ovoviviparous breeder.
35
Family:
6¥ifliobatyS feoyocaudatys -
Myliobatidae
eagle ray, whiptail
(tenuicoudatus = slender-tailed)
DESCRIPTION:
This ray is easily distinguished from the stingrays by the
snout which is distinct from the pectoral fins forward of the level of the
eyeso
The body disc is diamond-shaped and wider than it is long.
The
tail is long and slender with two venomous spines present at the base.
Colour varies in this species from a mottled greenish-grey to almost black.
Eagle rays can grow to 1.2m in width.
They are solitary fish and
are usually seen resting on the bottom or swimming close to the substratum.
They swim like the stingrays, by beating the
pectoral fins.
However, the
pectoral fins move in opposite phase whereas the stingrays beat their fins
simultaneously.
DISTRIBUTION:
General?
Australia.
This species is found in New Zealand and southern
In New Zealand, they wander as far south as Otago but are most
abundant north of Cook Strait, especially in the Hauraki Gulf where they
are frequently seen in shallow waters over the summer.
Local:
This is the most common ray of the Reserve.' Individuals
range over the whole reef and are not found in any particular habitat.
FEEDING:
Af. tenuicaudatus appears to be restricted to foraging over rocky
bottoms.
They move slowly over the bottom, wrenching their prey from the
rockc
Hard-shelled prey are crushed with pavement-like, heavily denticulated
teeth plates.
Food consists mainly of crabs, gastropods and hermit crabs.
Observations on feeding behaviour suggest the eagle ray crushes its prey
and expels the shell fragments from its mouth.
No shell fragments have
been found in the stomach.
LIFE HISTORY:
The life history features of this species are poorly known.
Reproduction is ovoviviparous0
37
Family :
Torpedo fairchaldio DESCRIPTION;
elect he ray,
Torpedinidae
torpedo ray
Several features distinguish this species from the other
rays found in the Reserve»
The head and pectoral fins form a distinct disc
which is well separated from the thick rounded tail.
fin and two dorsal fins „
or greyish-brown o
Scales are absent0
There is a caudal
Colouration is a mottled grey
The torpedo ray can reach up to 1« 2m in length«,
This fish is able to deliver an electric shock if touched*
There
is an electric organ on either side of the head, between the upper and
lower surfaces of the skin.
These are kidney-shaped groups of hexagonal
cells which are filled with a clear jelly-like substance»
charge is generated here*
The electric
The discharge is of sufficient strength to
knock out a grown man for an hour or so*
The ray is capable of delivering
40-50 consecutive shocks, each one becoming weaker.
A period of rest is
then required for the fish to recover .
Torpedo rays are poor swimmers and are usually encountered buried
in sand^ with only their eyes and spiracles protruding,,
DISTRIBUTIONi
General:
This species is found in south-east Australian seas
and around New Zealand.
They are widely distributed around the entire New
Zealand coastline to depths of 200m»
Locals
Although T.foivohitdi tend to prefer deep waters they
are occasionally seen inshore and have been reported in the Reserve at
depths of about 14m0
FEEDING^
Small fish are the major prey for this species„
and shrimps are also eaten.
Shellfish, crabs
Fish are caught by the ray enveloping them
from above, with their pectoral fins„ and stunning the prey with an electric
shocko
LIFE HISTORY:
this specieso
Little is known of age^ growth .or reproductive habits of
Diet
This page has
intentionally been
left blank
40
This class incorporates the vast majority of living fishes, both
freshwater and marine.
The presence of bone is the major character
distinguishing them from the jawless fishes (class Agnatha) and the
cartilaginous fishes (class Chondrichthys).
The bony fishes can be separated into four divisions . The first
three; the lobef ins,, the lungfishes, or coelocanths, and the birchirs are
primitive groups of fishes with large numbers of species known from the
fossil record, but with few living representatives.
The fourth group,
the teleosts, includes the majority of present day fishes and consists of
about 20,000 species.
features:
The teleosts are charcterised by the following
(1) A well developed, bony vertebral column and skull; (2)
which are supported by soft or spiny rays; (3)
A single gill cover, or
operculum, which covers the cavity containing the gills„
Scales may be
present or absent.
The general features of a teleost fish.
the characters illustrated)0
Fins
(No one species exhibits all
41
©FIDER AMGUILUFORMIES -
the eels
This is a specialised group of species which have become adapted
to living in narrow holes and crevices,
slendero
The body has become long and
The pelvic fins are reduced and a continuous dorsal-anal fin
has developed.
All fins are spineless *
The gill openings have been
reduced to small slits on either side of the head and are without gill
covers.
skin.
Scales, when present, are minute and deeply embedded into the
The swim bladder retains its primitive condition in these bottom
dwellers»
Many species are nocturnal and have a well developed sense of
smell for tracking prey.
The nasal tubes are pronounced and set well
apart „
The eels® eyes differ from other fish as the iris is able to
contract and expand, thus controlling the amount of light reaching the
retina.
The eyes are covered with a protective skine
Because the eels lack gill cover with which to set up a bellows
motion and keep water flowing over the gills, they must always keep their
mouths open, forcing water toward the gills with a swallowing motion.
These fish achieve their snake-like movement along the bottom by a
series of transverse waves travelling the length of the body and increasing
in magnitude from nose to tail (anguilliform locomotion) .
This order is comprised of 20 families.
in New Zealand»
Several species are found
Few are of any commercial value as most are uncommon and
infrequently caught»
Only three families are represented in tbe Reserve»
Family IMyrasniitiia© -
morays
These are usually large, powerful eels, some reaching lengths of
3mo
They have no pectoral fins, the gill openings are small and the mouth is
large with strong, sharp teethe
The body is typically flattened -
from side to side and the scaleless skin is thick and leathery»
fin always begins on the head.
The dorsal
Individuals are usually brightly coloured»
The morays constitute a family of more the 80 species occurring in
their greatest abundances in tropical and subtropical waters, with a few
species straying into temperate regions.
They live in shallow coastal waters
and most species are nocturnal»
Several species occur in north-eastern New Zealand waters.
one, Gymnothovox prasinus, the yellow moray, is common.
moray species found in the Reserve.
Only
This is the only
The other species are
rare on the coast,
but are more abundant in the warmer waters around offshore island groups
42
such as the Poor Knights Islands and the Moko Hinau Islands.
These-are:
the grey moray, Gymnothorax nubilus; the speckled moray, G. obesus-, the
mottled moray. Goprionodon and the mosaic moray^ GoVamosus.
conger eels
This is a small family of marine eels.
They are distinguished from
the morays by possessing pectoral fins and a black margin on the dorso-anal
finc
The dorsal fin begins above the pectoral fin *
These are large powerful eels which can grow up to 3m long and weigh
up to 80kgo
They are found at moderate depths in most tropical and
temperate seas of the world.
Several conger eels are found in New Zealand waters„
found around the rocky coasts?
Only two are
the southern species, Conger verrauxi and
the northern species, C.wiZsoni•
The others occur in deep, offshore waters;
Gnathophis habenatus3 G«ymbvettabia3 Bassanago bulbiceps and B.hivsutus.
snake eels
Snake eels are known throughout the world in tropical and subtropical
seaso
A few species range into temperate waters»
brightly coloured and are often strikingly
They are typically
marked with bands or spots»
Only a few of the many species reach lengths exceeding lm;
less than 300mm long,»
most of them are
They dwell in shallow waters on coral and rocky reefs
and also sandy and muddy bottoms»
Some species are burrowing»
They body is elongate, cylindrical and scaleless.
The dorsal and
anal fins are not confluent, leaving the tip of the tail free0
Pectoral
fins are small or lacking and there is no caudal fin»
The tail is stiff
and sharp rather than broad and flat as in the morays»
The snout may be
short or long but usually projects beyond the lower jaw»
The nostrils
are located on two short stout barbels on top of the nose, which the eels
use to probe into crevices and cavities in their search for food»
43
Family:
Gfmsnothorais prasinus
DESCRIPTION:
-
yellow
Muraenidae
moray
This large, powerful eel grows to about 1m in length0
average size ranges between 500 and 600mm.
The
This species is easily
recognised by its yellow or yellow-green uniformly coloured body*
Other
distinguishing features are-the absence of pectoral fins, the reduced gill
openings and the long slender jaws.
Several rows of sharp, prominent teeth
are present in each jaw.
The yellow morays are nocturnal, sheltering in cracks and crevices
during the day.
Individuals are solitary and home ranging and may return
to use the smae shelter site each day.
Although they will share a shelter
hole with another individual belonging to a different species of moray,
these fish may defend territories from other members of their species.
Highly intensive aggressive encounters have been observed between yellow
morays»
DISTRIBUTION :
Generals
This species is widely distributed throughout the
Indo-=Pacific region. In New Zealand they are found around the entire North
Island coastline» They prefer areas of rocky coasts, especially around
headlands.
Local:
In the Reserve, the yellow moray can be found on the
rocky reef wherever there is suitable shelter.
They are most abundant in
broken, rocky areas.
FEEDING:
Morays forage actively at night, moving from cover to seek prey.
Some feeding may occur during the day; however, foraging is probably
confined to shelter holes.
The diet consists mainly of crabs and small
nocturnal fishes such as the scorpion fish, Scorpaena
LIFE HISTORY:
species.
cardinaUs.
No information is available on the life history of this
45
Family:
Conger WBflSOra DESCRIPTION:
conger
Congridae
eel
The conger eel can be distinguished from the moray by its
body form and colouration.
It possesses small pectoral fins, the dorsal
fin begins further along the back, the eyes are oval and much larger than
the moray's and the dorso-anal fin is edged with black*
Body colouration
varies in these fish from a dark grey-blue black with a pale ventral
surface to
a pale brown back with a brown and white mottled undersurface.
The average size is 750-900mm in length, but these fish can grow
to reach 2m in length, weighing up to 18kg„
The males tend to be smaller
than the females and have relatively larger head and eyes »
Conger eels are solitary fisho
They are nocturnal and inhabit
narrow holes and crevices during the day»
DISTRIBUTION:
General:
This species has been recorded from Australia, New
Zealand and Lord Howe Island„
It is moderately common around the rocky
coasts of the North Island but its southern extent is poorly known»
Locals
of the Reserve»
Conger eels have been seen at all depths in the waters
They are usually found in areas where the rock is broken
and there are plenty of the deep holes and crevices which are required for
sheltero
FEEDING:
CoWilsoni forages in the open at night»
It is an opportunistic
predator, taking any mobile animal of suitable size»
eat mainly crabs and hermit crabs»
Small conger eels
The larger eels also take small reef
fish, e.g. marblefish, A»meandratus; kelpfish, C.marmoratus and blennioid
fishes o
LIFE HISTORY:
conger eel»
Little is known of age, growth or breeding habits of the
Females kept in aquaria
as 3 million eggs»
have been known to produce as many
Cooger
wilsoni
to 2m
New Zealand distribution
Diet
\ Hermit crabs
5 %