132 
Fishery Bulletin 117(3) 
Table 3 
Estimates of von Bertalanffy growth curve parameters for invasive red lionfish (Pterois volitans ) collected from 2012 through 2015 
in 3 ecological regions (ecoregions) in the northern Gulf of Mexico: southeast (SE; Florida Keys north to Anclote Keys, Florida), 
northeast (NE; Anclote Keys north to Mobile Bay, Alabama), and central (C; west of Mobile Bay to Galveston Bay, Texas). The 
parameters are growth rate (K), asymptotic length (L„, given in millimeters in total length), and theoretical age when the length 
is zero (t 0 ). (A) Comparisons among ecoregions by sex. (B) Comparisons between sexes by ecoregion. A sum of square reduction test 
was used to determine differences in growth between ecoregions and sex by comparing nonlinear trends between groups (a -0.0b;. 
Pooled 
Female 
Male 
Parameter 
SE 
NE 
C 
SE 
NE C 
SE 
NE 
C 
K 
0.569 
0.544 
0.539 
0.574 
0.549 0.542 
0.576 
0.547 
0.543 
423.0 
393.0 
389.0 
382.0 
366.8 360.9 
426.0 
394.4 
390.7 
*0 
-0.155 
-0.079 
-0.341 
-0.165 
-0.089 -0.350 
-0.170 
-0.086 
-0.354 
^12,1412=27.143, PcO.OQl 
^12,626=7.303, P<0.001 
Pl2,695=12.606, P<0.0Q1 
B 
Southeast 
Northeast 
Central 
Pooled 
Parameter 
Male 
Female 
Male 
Female 
Male Female 
Male 
Female 
K 
0.576 
0.574 
0.547 
0.549 
0.543 
0.542 
0.550 
0.508 
L„ 
426.0 
382.0 
394.4 
366.8 
390.7 
360.9 
405.2 
368.4 
*0 
-0.170 
-0.165 
-0.086 
-0.089 
-0.354 
-0.350 
0.414 
-0.482 
■^8,453= 
2.412, P=0.0Q8 
^8,489= 
2.012, P=0.030 
•Fj 8 j3 79=2.362, P- 
=0.010 
P 813 2i=16.226,P<0.001 
parameters determined from data pooled across all 3 ecore¬ 
gions indicate that males also had higher K and values 
than females (Table 3B, Fig. 7D). 
Discussion 
The results of this study reveal significant ecoregion- and 
sex-specific patterns in age, growth, and weight-length 
relationships of red lionfish. The K values of red lion- 
fish collected from the southeast ecoregion were higher 
than those of red lionfish from the northeast and central 
ecoregions. Although it was expected that K values would 
be greater for the red lionfish collected in the southeast 
ecoregion, the ,o„ values of many fish species are usually 
lower in the more southern regions of their geographic 
range than in the more northern regions (Boehlert and 
Kappenman, 1980) because fish species from northern lat¬ 
itudes typically achieve larger sizes than fish species from 
southern latitudes (Lindsey, 1966). The observed anomaly 
in values may also be a result of density-dependent 
growth, as has been documented in invasive red lionfish 
on small artificial reefs in the Bahamas (Benkwitt, 2013). 
Red lionfish collected from the northeast ecoregion in par¬ 
ticular came from much smaller and isolated artificial 
and natural reefs and were found in much higher densi¬ 
ties compared with densities observed on the reefs in the 
southeast ecoregion (senior author, unpubl. data). 
The results of our marginal increment analysis indi¬ 
cate that annuli on otoliths from red lionfish were most 
complete in the spring (March-May) and least complete 
in the fall (September-October), a finding similar to that 
for another scorpaenid, the native blackbelly rosefish 
{Helicolenus dactylopterus), off the coasts of North and 
South Carolina (White et ah, 1998). In contrast, black 
scorpionfish (Scorpaena porcus ) from the Adriatic Sea 
had their most complete annuli in the late summer (July— 
September; La Mesa et aL, 2010). Comparable thermal 
regimes between the northern GOM and North and South 
Carolina likely are the reason for the similar trends in 
annuli formation between invasive red lionfish and native 
blackbelly rosefish; similar trends have been documented 
in red snapper (Lutjanus campechanus) from similar ther¬ 
mal regimes (Nelson and Manooch, 1982). Black scorpi¬ 
onfish from the Adriatic Sea likely have delayed annuli 
completion compared with the annuli formation of the 
red lionfish in our study because of the relatively cooler 
sea-surface temperatures (~11°C) that that they experi¬ 
ence in the spring. Sea-surface temperatures in the Adri¬ 
atic Sea warm to above 20°C in July (La Mesa et al., 2010), 
similar to sea-surface temperatures observed in March 
in the northern GOM. Therefore, water temperature may 
drive annuli completion in these species, as has been 
reported for other species and regions (Pearson, 1996). 
Age estimation was challenging for some red lionfish 
in our study, with an APE of 12.1 between readers for 
