339
ABSTRACT. Engraulis anchoita
sagittal
==
Engraulis
a
±
±
E. anchoita
Key words:
Edad y crecimiento diario de juveniles de Engraulis anchoita del sur de Brasil
RESUMEN. Engraulis
anchoita sagitta
==
Engraulis
a
Age and daily growth of juveniles Engraulis anchoita from southern Brazil
3
3
Daniel R. Brown EzequielLeonarduzzi
Claudio C. Buratti Felipe Carvalho
Marine and
Fishery Sciences
MAFIS
Marine and Fishery Sciences 38 (3): 339-355 (2025)
Engraulisanchoita
°
Engraulis
anchoita
±
±E. anchoita
Palabras clave:
Brown et al.: Age and daily growth of Engraulis anchoita juveniles
E. anchoita
E. anchoita
Data collection and otolith reading
Engraulisanchoita
Marine and Fishery Sciences 38 (3): 339-355 (2025)
342
During the austral spring (September-October),
the south Brazilian shelf experiences the inuence
of the Brazil Current along the slope, with surface
temperatures typically ranging from 20-22 °C
(Sasaki et al. 2024). The upwelling of nutrient-rich
South Atlantic Central Water (SACW) begins along
the mid and outer shelf, supporting productivity.
Nearshore areas are inuenced by fresher, colder
Coastal Water (CW), while the oshore regions see
saltier, warmer Tropical Water (TW; Sasaki et al.
2024). These dynamics create stratication that can
aect juvenile anchovy distribution.
Specimens measuring less than 116 mm in total
length (TL) were classied as juveniles according
to Hansen (2000). A total of 90 individuals were
collected for analysis. Individuals were measured
to the nearest millimeter and their heads were pre-
served in ethanol (96%) inside plastic tubes for later
analysis. The sagittae otoliths were then washed
in the laboratory and mounted in slide glass with a
transparent mounting medium. Due to their thick-
ness, after drying the medium (48 h), otoliths were
manually ground in decreasing porosity with 12, 9
and 3 µm lapping lm paper. The polishing process
was carried out until the entire microstructure was
visible on the same plane. The identication of the
daily deposition pattern in the otoliths was made
following the criteria adopted by Cermeño et al.
(2003, 2008) for juveniles E. encrasicolus, Namiki
et al. (2010) for specimens E. japonicus, and Cerna
and Plaza (2016) for juveniles E. ringens.
The number of daily increments was counted
and their width was measured on the otoliths along
the longest axis using a digital camera attached
to a transmitted light microscope (400-1,000X),
connected to an image analysis software (Kontron
program). Two readers participated in the reading
of otoliths and discussed the microstructure anal-
ysis with each other. The otolith with the clearest
microstructure was selected for increment counting
and measurement. The number of increments in
the other otolith of the pair was determined by di-
rect counting. If there was at least 90% agreement
between counts of both otoliths (e.g. 100 and 110
increments), the data were included in the analysis.
However, if the discrepancy exceeded 10%, the
sample was excluded. If only one otolith was avail-
able due to the loss of the other during extraction
or polishing, such information was used. Out of a
total of 90 individuals captured, the age of 73 was
determined, because 17 specimens were discarded
due to discrepancies in increment counts or di-
culties in microstructure interpretation.
Preliminary analysis
Hatching dates were determined by subtracting
the number of daily increments from the date in
which each individual was caught. For ease of in-
terpreting seasonal trends, we grouped specimen
ages into 30-day intervals that roughly correspond
to months.
Table 1. Basic statistical values of sizes and ages of juveniles Engraulis anchoita from southern Brazil in September and October
2010 and 2011. SD: standard deviation.
Total length (mm) Age (days)
Year Vessel Catch date N Average ± SD Min. Max. Average ± SD Min. Max.
2010 ‘Atlantico Sul’ Sep 24 14 68.4 ± 6.4 57.1 80.0 148.8 ± 30.8 108 206
Sep 26 13 49.3 ± 9.0 37.4 63.6 94.8 ± 18.0 66 122
Oct 10 32 52.1 ± 6.6 42.5 62.9 107.5 ± 23.1 70 145
2011 ‘Victoria Mar’ Sep 22 14 79.7 ± 4.3 70.9 85.7 172.6 ± 31.8 75 207
Brown et al.: Age and daily growth of Engraulis anchoita juveniles
th
ith
i
i=abi
ab
=ab
=ab=
=
=
=
TLjiTLjin
niTLjiTLj
i +ii +
j
E.anchoita
===
Eanchoita
Seasonal dierences
Marine and Fishery Sciences 38 (3): 339-355 (2025)
log(rate) ~ month + age + month × age random =
~ 1|individual
log(rate)
month
age
month ×age
individual month
=+
=<
E. anchoita
µµ
µ
Brown et al.: Age and daily growth of Engraulis anchoita juveniles
±
±±
<
sagittaEngraulisanchoita
Marine and Fishery Sciences 38 (3): 339-355 (2025)
Eanchoita
Engraulis
E.encrasicolus
E. encra-
sicolusEngraulis ringens
Engraulisanchoita
==
Engraulisanchoita
Brown et al.: Age and daily growth of Engraulis anchoita juveniles
E. mordax
Engraulis
anchoita
Engraulisanchoita
Marine and Fishery Sciences 38 (3): 339-355 (2025)
Engraulisanchoita
>
<
<
<
Engraulisanchoita
Engraulisanchoita
Brown et al.: Age and daily growth of Engraulis anchoita juveniles
E. encrasicolus
Engraulisanchoita
Engraulis
Engraulis ringens
Engraulis ringens
Engraulis encrasicolus
Engraulis encrasicolus
Engraulis encrasicolus
Engraulis encrasicolus
Engraulis encrasicolus
Engraulis anchoita
Marine and Fishery Sciences 38 (3): 339-355 (2025)
±
±
±
Eanchoita
E. anchoita
a
aperse
E. encrasicolusa
a
µEngraulisanchoita
Brown et al.: Age and daily growth of Engraulis anchoita juveniles
Engraulisanchoita
a
Marine and Fishery Sciences 38 (3): 339-355 (2025)
E.ringens
Eanchoita
Eencrasicolus
Author contributions
En-
graulisencrasicolus
Engraulisencrasicolus
Engraulisencrasicolus
Engraulisan-
choita
Engraulisencrasicolus
Brown et al.: Age and daily growth of Engraulis anchoita juveniles
Engraulisencrasicolus
Engraulisencrasicolus
Engraulisanchoita
En-
graulisanchoíta
Gadusmorhua
Engraulisanchoita
Engraulisanchoita
Engraulisanchoita
Engraulisringens
Engraulisanchoita
Engraulisencrasicolus
Engraulisanchoita
Engraulisan-
choita
Marine and Fishery Sciences 38 (3): 339-355 (2025)
Engraulisanchoita
Gadusmorhua
Engraulisanchoita
En-
graulisanchoita
Gadusmorhua
Scomberjaponicus
Engraulisanchoita
Engraulisencrasicolus
Engraulisanchoita
Engraulisanchoita
Engraulisjaponicus
Brown et al.: Age and daily growth of Engraulis anchoita juveniles
Engraulis
ringens
Soleasolea
En-
graulismordax
Sardinops mela-
nosticus
Sardinops
melanosticus
Engraulisjaponicus
