Villanueva Gomila et al.: Early life history of Acanthistius patachonicus 
459 
Figure 1 
Distribution of larvae of Acanthistius patachonicus collected on the Argentine 
shelf, 2008-2013. The shaded area of water indicates the approximate distri- 
butional range for this species determined by Cousseau and Perrotta (2000). 
Only the oceanographic stations within the area of this range were plotted. 
The diameters of dots, classified into 3 categories, are proportional to larval 
abundance at each station. The open triangle indicates the position where ripe 
adults were caught for the fertilization experiment. The open circle indicates 
the area where the posttransition juvenile was caught. WD and ED indicate 
the western and eastern domains within the San Jose Gulf (sensu Amoroso and 
Gagliardini [2010]). 
the posttransition juvenile were cleared and double 
stained with alcian blue and alizarin, according to Pot- 
thoff (1984) and Taylor and Van Dyke (1985). Different 
development stages were illustrated according to the 
guidelines of Trnski and Leis (1991). 
Results 
Eggs and yolk-sac larvae 
The pelagic eggs in A. patachonicus were spherical, 
with a mean diameter of 1.1 mm (standard deviation 
[SD] 0.1), lacked pigmentation, and had a single, pale 
yellow oil globule (mean diameter: 0.2 mm [SD 0.1]) 
and a clear, segmented yolk (Fig. 2). The thin perivitel- 
line space (mean: 0.2 mm [SD 0.1]) had no pigmenta- 
tion, and the chorion was translucent. 
Recently hatched larvae had a small, ovoid yolk sac 
that represented -17% of BL, with 1 oil globule located 
anteriorly. The eyes were unpigmented and the mouth 
was not yet formed at this stage (Fig. 3A). 
Morphology and development of larvae and posttransition 
juveniles 
Four larvae were deposited as vouchers in the ich- 
thyological collection of the Centro Nacional Patagoni- 
co: CNPICT 2009/21, flexion, broken larva, 41°25'S, 
63°19'W; CNPICT 2009/22-1, postflexion, 7.6 mm, 
41°20'S, 63°00'W; CNPICT 2009/22-2, flexion, 7.5 mm, 
41°20'S, 63°00'W; CNPICT 2011/7, preflexion, 5.0 mm, 
42°17'S, 64°21'W. 
Body shape The smallest preflexion larva collected 
(2.2 mm) had round and incipiently pigmented eyes; 
the yolk was completely absorbed, and the mouth was 
terminal and open (Fig. 3B). Notochord flexion began 
at about 4.9 mm and was completed by 7.6 mm. The 
coiled digestive tract was already evident at preflexion. 
Larval development was a gradual process. However, 
some discontinuities in body proportions were evident 
between larvae of 2. 2-3.0 mm and larger individuals 
(Fig. 4). Head length was moderate, averaging 23% 
BL in larvae <4.2 mm, and was 28%-35% in larvae 
