REV. INVEST. DESARR. PESQ. Nº 17: 43-53 (2005)
MORPHOLOGICAL DEVELOPMENT OF THE MOUTH AND IMPROVEMENT
IN FEEDING ABILITY IN THE EARLY LARVAL STAGES OF RED PORGY,
Pagrus pagrus (L.)*†
by
EDDIE O. ARISTAZABAL
Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP),
Paseo Victoria Ocampo Nº l, Escollera Norte, B7602HSA - Mar del Plata, Argentina
e-mail: [email protected]
SUMMARY
The appearance, ossification and growth of cartilaginous structures of the mouth in early larval stages of laboratory
reared red porgy, Pagrus pagrus, were examined. At the time of mouth opening, red porgy larvae are equipped with the
fundamental components of the oral cavity to allow the sucking motion for acquiring food. During the initial feeding
stage, from day 5 after hatching (AH) to day 7 AH, the hyoid and lower branchial archs were completed, and the head
length and other structural elements, like the ceratohyal-epihyal cartilage, increased rapidly. These events intensified
sucking mechanisms by increasing the amount of ingested rotifers. After day 13 AH, the presence of the bony premaxilla and angular, the ossification of the Meckel´s cartilage and the appearance of pharyngeal teeth (ceratobranchial
teeth), allowed grasping of food items. Finally, at the end of the study period, the appearance of new elements, the ossification of previous ones, and the improvement of swimming capacity, increased the amount of ingested rotifers by the
combination of sucking and grasping mechanisms. As a result of the cartilaginous-osteological development of the
mouth, a modification of the feeding schedule of red porgy larvae reared in captivity is proposed.
RESUMEN
Desarrollo morfológico de la boca y mejoras de la habilidad alimentaria en los estadios larvales tempranos del
besugo Pagrus pagrus (L.). Se examinó la aparición de las estructuras cartilaginosas de la boca y su osificación y crecimiento en larvas del besugo Pagrus pagrus obtenidas en laboratorio. Al momento de la apertura de la boca, las larvas
están equipadas con los elementos estructurales fundamentales de la cavidad oral para adquirir alimento por succión.
Durante la fase inicial de alimentación, entre el quinto y séptimo día después de la eclosión (DDE), se completó la formación de los arcos hioide y branquial inferior, a la vez que se incrementó rápidamente el largo de la cabeza y de otros
elementos, como el cartílago ceratohial-epihial. Estas estructuras mejoran la capacidad de succión que se refleja en un
aumento del número de rotíferos ingeridos. Transcurridos 13 DDE, la presencia del premaxilar y angular óseos, el
comienzo de la osificación del cartílago de Meckel y la aparición de los dientes faríngeos (ceratobranquial), permitieron
desarrollar también el mecanismo de alimentación por captura. Finalmente, durante las últimas etapas del estudio, las lar*Contribución INIDEP Nº 1353
†This work is part of the Doctorate Thesis degree of the author.
43
44
REV. INVEST. DESARR. PESQ. Nº 17: 43-53 (2005)
vas de besugo utilizaron para alimentarse una combinación de succión y captura, posibilitadas por la aparición de nuevos elementos estructurales, por la osificación de otros pre-existentes y por la mejora de la capacidad de natación. A partir de los resultados del estudio del desarrollo cartilaginoso-osteológico, se propone modificar el esquema alimenticio de las larvas de besugo criadas en cautiverio.
Key words: Pagrus pagrus, larval development, feeding, osteology, mouth parts, marine fish culture.
Palabras clave: Pagrus pagrus, desarrollo larval, alimentación, osteología, partes de la boca, cultivo de peces marinos.
INTRODUCTION
The red porgy, Pagrus pagrus, is an important
commercial species from the coasts of Buenos
Aires Province, Argentina. Natural spawning of a
broodstock has been achieved through photoperiod and temperature manipulation at the National
Fisheries Research and Development Institute
(INIDEP) (Aristizabal Abud et al., 1997;
Aristizabal Abud, 2003). For this reason, the
study of larval development of red porgy is a key
feature not only to understand those factors
affecting early stages but also to improve aquaculture techniques applied to this species.
The transition from endogenous to exogenous feeding is one of the most critical periods
in the development of marine fish larvae
(Conides and Glamuzina, 2001; Moteki et al.,
2001) and is the cause of mass mortalities
(Kamler, 1992), which have been clearly
observed in captivity (Kanazawa et al., 1989;
Nakagawa et al., 1991; Ottera, 1993; Kjorsvik
and Holmefjord, 1995; Hernández-Cruz et al.,
1999; Dou et al., 2003). Kohno et al. (1997)
examined the osteological development of the
oral cavity in early stages of Epinephelus
coioides and concluded that the delayed development of the feeding apparatus caused difficulties in larval rearing. Machinandiarena et al.
(2000) studied external morphologic development of larvae and juvenile red porgy reared in
captivity, while Aristizabal Abud (2003), provided detailed information on the energetic
events of the transition from endogenous to
exogenous nutritional sources in the same
species.
This paper reports the cartilaginous-osteological development of the mouth in early stages of P.
pagrus larvae, in order to have a better understanding of their feeding mechanisms and the
effect of the appearance of those structures on
their feeding ability.
MATERIALS AND METHODS
Fertilized eggs of P. pagrus were collected
from natural spawnings of the broodstock at the
Laboratory of Mariculture at INIDEP, with a
planktonic net 300 µm mesh, and transferred to a
circular 0.5 m3 fiberglass tank. During incubation and larval rearing, water temperature was
kept at 18.0 ± 0.5 °C, salinity ranged from 33‰
to 34‰, and the photoperiod was set to 12 h L:
12 h D. Two experimental tanks connected to a
recirculation system were stocked with 26,000
larvae each. Larvae were fed with rotifers
(Brachionus plicatilis) at densities greater than
10 individuals ml-1.
From time of hatching to day 21 after hatching
(AH), 20 larvae were daily removed from the
tanks, anesthetized and preserved in 10% neutralized formalin. Before preservation (Klaoudatos et
al., 1990), total length was measured on live
specimens from the tip of the snout to the end of
the caudal fin. Head length was measured from
the tip of the snout to the posterior margin of the
cleithrum. Larvae were stained for bones and cartilage following a modification of the method
described by Potthoff (1984) and Taylor and van
Dyke (1985). Mouth opening was measured
using the length of the Meckel´s cartilage according to the formulae proposed by Shirota (1970):
ARISTIZABAL: DEVELOPMENT OF THE MOUTH IN EARLY STAGE LARVAE OF RED PORGY
Mo = 2 x Mc
Heartbeat rate was measured under the microscope only at time of measurement and for 1
minute in order to avoid changes of heartbeat rate
owing to extreme conditions of light and temperature under the microscope.
RESULTS
The eggs of the red porgy are spherical with a
mean diameter of 903 ± 12 m. They have a single oil
globule with a diameter of 180-220 µm. Hatching
occurred after 48-50 hours at 18 °C. Newly hatched
larvae of P. pagrus have a mean total length of 2.32
± 0.12 mm. Eyes are unpigmented, the mouth is
undifferentiated and the anus is closed. The diges-
45
tive tract is visible as a straight thin tube over the
yolk sac. With the exception of sporadic pulses of
activity, larvae do not move during the first 24
hours. The body of the larva is surrounded by the
primordial fin. There are 2-3 chromatophore cells
on the yolk sac and the oil globule, and several others randomly located on the sides of the body.
At day 1 AH, the mean total length of the larva
is 2.86 ± 0.12 mm, otoliths become visible at the
head region, and mean heartbeats are 81 min-1.
The pigmentation pattern has not changed.
Xanthophores were distinguished all over the
body, mainly in the head and around the tail, and
the body is almost straight. At day 2 AH, the
mean total length of the larva is 3.11 ± 0.10 mm,
blood circulation is not yet visible, and heartbeats
increase to 148 min-1. Auditory capsules are visible and the convolution process of the digestive
tract has started (Figure 1).
Figure 1. Image of a yolk sac larvae of red porgy 2 days after hatching.
Figura 1. Larva de besugo con vitelo dos días después de la eclosión.
46
REV. INVEST. DESARR. PESQ. Nº 17: 43-53 (2005)
Figure 2. Development of the oral cavity and related structures in the larvae of red porgy. A) 3 days after hatching (DAH). B) 5
DAH. C) 21 DAH. D) Branchial arch 5 DAH. ACp = anterior-directed coracoid process; An = angular; Bb = basibranchial;
Br = brachiostegal ray; Cb1 = ceratobranchial 1; CEc = ceratohyal-epihyal cartilage; Ch = ceratohyal; Cl = cleithrum;
CSc = coraco-scapular cartilage; De = dentary; Ec = ethmoid cartilage; EEb = ectethmoid bar; Et = epiphysial tectum; Fr
= frontal; Hb1 = hypobranchial 1; Hh = hypohyal; Hm = hyomandibular; Ih = Interhyal; Mc = Meckel´s cartilage; Mx =
maxilla; PCc = palatoquadrate cartilage; PCp = posterior-directed coracoid process; Pmx = premaxilla; Pop = pre-opercle; Qu = quadrate; RAc = retroarticular cartilage; Sc = sclerotic cartilage; SCl = supracleithrum; SHc = symplectichyomandibular cartilage; Sy = symplectic; Tr = trabecula. Stripped area, cartilage; open area, ossification.
Figura 2. Desarrollo de la cavidad oral y estructuras relacionadas de larvas de besugo. A) 3 días después de la eclosión (DDE).
B) 5 días DDE. C) 21 días DDE. D) Arcos branquiales, 5 días DDE. ACp = proceso coracoide anterior; An = angular;
Bb = basibranquial; Br = radio braquiostegal; Cb1 = ceratobranquial 1; CSc = cartílago coraco-escapular; Ch = ceratohial; Cl = cleitro; De = dentario; Ec = cartílago etmoides; EEb = barra ectetmoides; Et = téctum epifisial; CEc = cartílago ceratohial-epihial; Fr = frontal; Hb1 = hipobranquial 1; Hh = hipohial; Hm = hiomandibular; Ih = Interhial; Mc
= cartílago de Meckel; Mx = maxilar; PCc = cartílago palatocuadrado; PCp = proceso coracoide posterior; Pmx = premaxilar; Pop = preopérculo; Qu = cuadrado; RAc = cartílago retroarticular; Sc = cartílago esclerótico; SCl = supracleitro; SHc = cartílago simpléctico-hiomandibular; Sy = simpléctico; Tr = trabécula. La zona sombreada representa el
cartílago y la blanca la osificación.
ARISTIZABAL: DEVELOPMENT OF THE MOUTH IN EARLY STAGE LARVAE OF RED PORGY
At day 3 AH, the mean total length of the larva
is 3.24 ± 0.70 mm. Eyes become pigmented and
move. The mouth is opened and the digestive
tract convulses and differentiates. The heartbeats
reach 160 min-1. Xanthophore cells decreased in
number and belt to the posterior spine and opercular area. The bony cleithrum and the coracoscapular cartilage appear, bearing the recently
formed pectoral fins (Figure 2 A). The first jaw
element to appear was the Meckel´s cartilage.
The bony maxilla was the first element to appear
in the upper jaw. The symplectic-hyomandibular
cartilage first appeared as an element of the suspensorium. The ceratohyal-epihyal cartilage from
the hyoid arch was detected. The cartilaginous
quadrate was detected in front of the symplectichyomandibular cartilage. The cartilaginous basibranchial and the two anterior-most ceratobranchials appeared as lower arch elements.
At day 4 AH, the mean total length of the
larva is 3.32 ± 0.15 mm. Blood circulation is
visible. The mouth and the digestive tract are
functional, and food particles can be found. The
edge of the primordial fin is serrated. Number of
chromophores has decreased while xanthophore
cells have disappeared. Only a small part of the
oil globule and yolk sac still remains. Heartbeats
increase to 260 min-1. At day 5 AH, the mean
total length of the larva is 3.54 ± 0.13 mm. The
yolk sac and oil globule have disappeared. A
dense blood circulation around organs can be
observed. The primordial fin is not divided yet
except a small notch appearing just behind the
head region. The symplectic-hyomandibular
cartilage presents a small foramen in the upper
part, while the coraco-scapular cartilage develops a small anterior-directed coracoid process
on the anteroventral part (Figure 2 B). The
hypohyal and interhyal cartilages were
observed. The hypobranchial 1 and ceratobranchial 3 and 4 were detected at the base of
the arch (Figure 2 D).
At day 6 AH, the mean total length of the
larva is 3.75 ± 0.12 mm. Traces of the caudal fin
47
rays appear, and the olfactory organ appears on
the snout of the larva. The chromophore cells
disappear except for some, randomly located
along the digestive tract. Some individuals bearing swim bladder were detected. Hearbeats
decrease to 206 min-1. At day 8 AH, the mean
total length of the larva is 4.30 ± 0.15 mm. The
digestive tract is complete, functional and full
of rotifers. The lateral arteries of the body are
visible. The opercle and pre-opercle are
observed. The bony dentary is formed in the
anterior part of the Meckel´s cartilage.
Ossification processes began at the lower and
upper part of the symplectic-hyomandibular
cartilage and on the anterior part of the ceratohyal-epihyal cartilage.
Larvae at day 10 AH, present a cartilaginous
occipital process and a single bony brachiostegal
ray. The cartilaginous palatine and the retroarticular cartilages were first detected. Between days 1315 AH, an anterodorsally directed projection from
the posterodorsal part of the Meckel´s cartilage
started to form, while the bony angular ossificates
from the posterioventral part of the Meckel´s cartilage. The bony premaxilla and the ossification of
the outer part of the ceratohyal-epihyal cartilage
were observed (Figure 2 C). The quadrate became
contiguous to the palatine to form the palatoquadrate cartilage A single tooth located at the ceratobranchial-1 was observed in some individuals.
The bony supracleithrum was observed at day
16 AH, with a posterior-directed spine evident at
the end of the study period. The parasphenoid and
the starting of notochord flexion were detected.
By day 21 AH, a single tooth was observed on the
dentary. The partial ossification of the symplectichyomandibular and quadrate cartilage was also
detected at this time. Four branchiostegal rays
were evident in the hyoid arch (Figure 2 C).
Head length and mouth opening increased linearly with time (Figure 3), while the ceratohyalepihyal cartilage showed an asymptotic growth
curve. Number of rotifers in the gut increased
with time (Figure 4).
48
REV. INVEST. DESARR. PESQ. Nº 17: 43-53 (2005)
Figure 4. Number of rotifers found in the gut of red porgy
larvae. The arrow indicates the time of mouth opening. Vertical bars show standard error. Sampling
was performed one hour after adding rotifers to the
larvae tank.
Figura 4. Cantidad de rotíferos encontrados en el intestino de
las larvas de besugo. La flecha indica el momento de
la apertura de la boca. Las barras verticales indican
el error estándar. El muestreo se realizó una hora
después del agregado de rotíferos al tanque de larvas.
DISCUSSION
Figure 3. Changes in head (A) and ceratohyal-epihyal cartilage length (B), and mouth opening (C) in larvae of
red porgy.
Figura 3. Cambios en la longitud de la cabeza (A), en la longitud del cartílago ceratohial-epihial (B) y en el
tamaño de la boca (C) de larvas de besugo.
Most teleost ingest their food by sucking
mechanisms created by the negative pressure of
the oral cavity (Gerking, 1994). At the time of
mouth opening, red porgy larvae are equipped
with the following fundamental components of
the oral cavity (Figure 5): the trabecula of the
neurocranium comprising the roof of the oral
cavity; the ceratohyal and epihyal from the
hyoid arch, and some other elements of the
lower branchial arch forming the cavity floor;
the quadrate and symplectic-hyomandibular
cartilages comprising the sides; and finally, the
bony maxilla and the Meckel´s cartilage as jaw
elements. The bony cleithrum and coracoscapular cartilage were also present at the time
ARISTIZABAL: DEVELOPMENT OF THE MOUTH IN EARLY STAGE LARVAE OF RED PORGY
of mouth opening. Matsuoka (1987) described a
large levator arcus palatini (peripheral head
muscles) 11 hs after mouth opening in larvae of
Pagrus major, which expands oral and
branchial cavities allowing sucking motion to
acquire food. Based on the development of the
mouth in early stages of the red porgy, previously mentioned muscles must be present in
this species too, when initial feeding starts, 24
h after mouth opening. It can be stated that
feeding during this time was performed exclusively by sucking mechanisms, because elements that facilitate the grasping of food, such
as the premaxilla and jaw teeth, were not present (Kohno et al., 1996 a). During the first days
of exogenous feeding, from day 5 to 7 after
hatching, hyoid and lower branchial archs were
completely formed (Figure 5). At the same time
the length of the head and the ceratohyal-epihyal cartilage were rapidly increased. Red
porgy larvae feed more as they grow, so the
improvement in their sucking ability during this
stage would depend mainly on size development (Moteki et al., 2001).
The respiratory gas exchange is basically
performed by the skin until the time of mouth
opening. Thus, the functional development of
the branchial system must be completed when
larvae reach a certain critical size, which is
around day 6 AH in this species (Aristizabal
Abud, 2003). Heartbeats decreased after mouth
opening, showing the participation of the
branchial system in the respiration.
After day 8 AH, several developments
occurred. These included the appearance of new
structures in the oral cavity, like the dentary,
opercle and preopercle. The general growth of the
larvae, the ossification of existing elements and a
rapid increase in bone length of the oral cavity
suggest an enhancement of feeding by sucking
mechanisms (Figure 5). Kohno et al. (1996 b)
described the shift in feeding mechanisms from
sucking to grasping, in larval sea bass Lates calcarifer. From day 13 AH, the appearance of the
49
bony premaxilla and angular, the ossification of
Meckel´s cartilage and the appearance of lower
pharyngeal teeth (ceratobranchial), would allow
feeding by grasping mechanisms (Moteki, 2002).
At day 16 AH, swimming became more active
and caudal propulsion increased supported by the
appearance of new fin elements and the starting
of the notochord flexion. According to
Machinandiarena et al. (2000), postflexion stage
was detected from day 29 AH. As larvae grew,
they started to swim against the current, and
deployed attacking movements over rotifers.
Larvae of P. pagrus share common osteological characters of sparids, like spines on the preopercle and supracleithrum (Houde and
Potthoff, 1976; Hussain et al., 1981; Griswold
and McKenney, 1984; Matsuoka, 1987; Zieske,
1989; Fukuhara, 1991; Tucher and Alshuth,
1997). The supraoccipital crest is not diagnostic
of sparids, but have been reported in a few
species (Leis et al., 2002).
Leis et al. (2002), stated that the Atlantic
species Pagrus pagrus have virtually identical
head spination to that of Pagellus species
(Figure 6), while the Mediterranean Pagrus
pagrus differ in having about one less spine in
all series. The same authors hypothesize that
Pagellus affinis, Pagellus bellotti and Pagelus
natalensis and Pagrus pagrus are closely related, and that the other described larvae of Pagrus
(the indo-Pacific P.auratus and P. major), do not
belong to the spiny Pagellus-Pagrus pagrus
clade. Although solving this problem is beyond
the scope of this paper, Leis et al. (2002) proposed an interesting taxonomic maze of relationships between sparid fishes, which will be
important for the development of specific rearing techniques for Pagellus-Pagrus larvae.
The present schedule of red porgy seed production at INIDEP follows the general development of the larvae. Rotifers are the first live food
item offered to larvae in the rearing tank from
the time of mouth opening to day 30 AH. The
shift to a second live food item (Artemia sp.),
50
REV. INVEST. DESARR. PESQ. Nº 17: 43-53 (2005)
Figure 5. Schematic representation of the development of elements comprising the mouth and fins of red porgy. (•) Appearance
of cartilaginous element; (•) appearance of ossified bone or the beginning of ossification of cartilaginous element.
Development refers to the enhancement of feeding ability and changes of feeding mode. For feeding mechanism, thickness of the arrows indicates the degree of ability in each mode.
Figura 5. Representación esquemática del desarrollo de los elementos de la cavidad oral y aletas de besugo. (•) Simboliza la aparición de un elemento cartilaginoso y (•) la aparición de un elemento óseo o el inicio de la osificación del cartílago. El
desarrollo hace referencia a los principales eventos que contribuyen a la mejora de los mecanismos alimenticios. El grosor de la flecha indica la capacidad desarrollada para cada tipo de mecanismo alimenticio.
ARISTIZABAL: DEVELOPMENT OF THE MOUTH IN EARLY STAGE LARVAE OF RED PORGY
51
Figure 6. 7.75 mm larvae of Pagrus pagrus reared at the laboratory (from Machinandiarena et al., 2000). Note supraoccipital
spine and strong preopercular spination.
Figura 6. Larva de Pagrus pagrus de 7,75 mm nacida en laboratorio (tomada de Machinandiarena et al., 2000). Se observan la
espina supraoccipital y las espinas preoperculares.
occurs from day 20 AH. Artemia nauplii is a
crustacean that actively move along the water
column in the rearing tank. At this time, feeding
by sucking alone would not be an efficient
mechanism to grasp Artemia nauplii. Based on
the feeding abilities developed by the red porgy
larvae and the mouth width, it would be possible
to schedule the time of Artemia nauplii supply to
start by day 13 AH, since larvae are ready to
feed by grasping mechanism. The possibility of
reducing the period of rotifer supply is very
important in terms of production workload, with
a consequent reduction of costs.
ACKNOWLEDGEMENTS
The author wishes to thank Lic. Laura
Machinandiarena for helping in the dyeing technique of larvae and the review of this paper. Also
Lic. Andrea López and Lic. Mariana Cadaveira
for the supply of microalgae and rotifers.
REFERENCES
ARISTIZABAL ABUD, E.O. 2003. Bioenergética del
besugo, Pagrus pagrus (L.). Tesis de
Doctorado, Facultad de Ciencias Exactas y
Naturales, Universidad Nacional de Mar del
Plata, 145 pp.
ARISTIZABAL ABUD, E.O., MULLER, M., BAMBIL,
G., LOPEZ, A., SABATINI, M., COSTAGLIOLA, M.,
INCORVAIA, S., VEGA, A., CARRIZO, J.C. &
MANCA, E. 1997. Producción de alimento vivo
y cría de besugo. Período 1995-1996. Inf. Téc.
Int. DNI-INIDEP Nº 83/97, 92 pp.
CONIDES, A.J. & GLAMUZINA, B. 2001. Study on
the early larval development and growth of the
red porgy, Pagrus pagrus with emphasis on
the mass mortalities observed during this
phase. Sci. Mar., 65 (3): 193-200.
DOU, S., MASUDA, R., TANAKA, M. &
TSUKAMOTO, K. 2003. Identification of factors
affecting the growth and survival of the settling japanese flounder larvae, Paralichthys
olivaceus. Aquaculture, 218: 309-327.
FUKUHARA, O. 1991. Size and age at transformation in red sea bream, Pagrus major, reared in
the laboratory. Aquaculture, 95: 117-124.
GERKING, S.D. 1994. Feeding ecology of fishes.
Academic Press, London, 420 pp.
GRISWOLD, C.A. & MCKENNEY, T.W. 1984.
Larval development of the scup, Stenotomus
chrysops (Pisces: Sparidae). Fish. Bull., U. S.,
82: 77-84.
HERNÁNDEZ-CRUZ, C.M., SALHI, M., BESSONART,
M., IZQUIERDO, M.S., GONZÁLEZ, M.M. &
52
FERNÁNDEZ-PALACIOS, H. 1999. Rearing techniques for red porgy (Pagrus pagrus) during
larval development. Aquaculture, 179: 489497.
HOUDE, E.D. & POTTHOFF, T. 1976. Egg and larval development of the sea bream
Archosargus rhomboidalis (Linnaeus): Pisces,
Sparidae. Bull. Mar. Sci., 26: 506-529.
HUSSAIN, N., AKATSU, S. & EL-ZAHAR, C. 1981.
Spawning, egg and early larval development,
and growth of Acanthopagrus cuvieri
(Sparidae). Aquaculture, 22: 125-136.
KAMLER, E. 1992. Early Life History of Fish. An
Energetic approach. Chapman & Hall,
London, 183 pp.
KANAZAWA, A., KOSHIO, S. & TESHIMA, S. 1989.
Growth and survival of larval red sea bream
Pagrus major and japanese flounder
Paralichthys olivaceus fed microbond diets. J.
World Aquacult. Soc., 20 (2): 31-37
KJORSVIK, E. & HOLMEFJORD, I. 1995. Atlantic
halibut (Hippoglossus hippoglossus) and cod
(Gadus morhua). In: BROMAGE, N.R. &
ROBERTS, R.J. (Eds.). Broodstock management and egg and larval quality, Blackwell
Science, Oxford, 169-196.
KLAOUDATOS, S., TSEVIS, N. & CONIDES, A. 1990.
Energy sources during early larval development of the European Sea Bass, Dicentrarchus
labrax (L.). Aquaculture, 87: 361-372.
KOHNO, H., ORDONIO-AGUILAR, R., OHNO, A. &
TAKI, Y. 1996 a. Morphological aspects of feeding mode and improvement of feeding ability
in early stage larvae of the milkfish, Chanos
chanos. Ichthyol. Res., 43: 133-140.
KOHNO, H., ORDONIO-AGUILAR, R., OHNO, A. &
TAKI, Y. 1996 b. Osteological development of
the feeding apparatus in early stage of larvae
of the sea bass, Lates calcarifer. Ichthyol.
Res., 43: 1-9.
KOHNO, H., ORDONIO-AGUILAR, R., OHNO, A. &
TAKI, Y. 1997. Why is grouper larval rearing
difficult? An approach from the development
of the feeding apparatus in early stage larvae
REV. INVEST. DESARR. PESQ. Nº 17: 43-53 (2005)
of the grouper, Epinephelus coioides.
Ichthyol. Res., 44: 267-274.
LEIS, J.M., TRNSKI, T. & BECKLEY, L.E. 2002.
Larval development of Pagellus natalensis
and what larval morphology indicates about
relationships in the perciform fish family
Sparidae (Teleostei). Mar. Freshwater Res.,
53: 367-376
MACHINANDIARENA, L., MÜLLER, M., LÓPEZ, A.,
ARISTIZABAL ABUD, E. & BAMBILL, G. 2000.
Desarrollo de los estadios iniciales del besugo
(Pagrus pagrus) en cautiverio, en la Provincia
de Buenos Aires, Argentina. Inf. Téc. Int.
DNI-INIDEP Nº 30/00, 16 pp.
MATSUOKA, M. 1987. Development of the skeletal tissues and skeletal muscles in red sea
bream. Bull. Seikai Reg. Fish. Res. Lab., 65:
1-114.
MOTEKI, M. 2002. Morphological aspects of feeding and improvement in feeding ability in the
early larval stages of red sea bream Pagrus
major. Fish. Sci., 68: 996-1003.
MOTEKI, M., ISHIKAWA, T., TERAOKA, N. &
FUSHIMI, H. 2001. Transition from endogenous to exogenous nutritional sources in larval
sea bream, Pagrus major. Suisanzoshoku, 49:
323-328.
NAKAGAWA, H., IMABAYASHI, H., KUROKURA, H.
& KASAHARA, S. 1991. Changes in body constituents of young red sea bream, Pagrus
major, in reference to survival during experimental stocking. Biochem. Syst. Ecol., 19 (2):
105-110.
OTTERA, H. 1993. Feeding, growth, and survival
of Atlantic cod (Gadus morhua) larvae reared
in replicate plastic enclosures. Can. J. Fish.
Aquat. Sci., 50 (5): 913-924
POTTHOFF, T., 1984, Clearing and staining techniques. In: MOSER, H.G., RICHARDS, W.J.,
COHEN, D.M., FAHAY-JR., M.P. KENDALL A.W.
& RICHARDSON, S.L. (Eds.). Ontogeny and
Systematics of Fishes. American Society of
Ichthyologists and Herpetologists, (Spec.
Publ. 1), Lawrence: 35-37.
ARISTIZABAL: DEVELOPMENT OF THE MOUTH IN EARLY STAGE LARVAE OF RED PORGY
SHIROTA, A. 1970. Studies on the mouth size of
fish larvae. Bull. Jap. Soc. Sci. Fish., 36 (4):
353-368.
TAYLOR, W.R. & VAN DIKE, G.C. 1985. Revised
procedures for staining and clearing small fishes and other vertebrates for bone and cartilage study. Cybium, 9 (2): 107-119.
TUCKER, J.W. & ALSHUTH, S.R. 1997.
Development of laboratory-reared sheepshe-
53
ad, Archosargus probatocephalus (Pisces:
Sparidae). Fish. Bull., U. S., 95: 394-401.
ZIESKE, G.G. 1989. Redescription of larvae of the
pinfish, Lagodon rhomboides (Linnaeus)
(Pisces, Sparidae). Contr. Mar. Sci., 31: 51-91.
Recibido: 15-04-2004
Aceptado: 24-10-2004