National Marine 
Fisheries Service 
NOAA 
Fishery Bulletin 
e established in 1881 << 
Spencer F. Baird fe i 
First U.S. Commissioner ey 4 
of Fisheries and founder Ei 
of Fishery Bulletin ee 
Abstract—Median length at maturity 
was determined for Pacific angel sharks 
(Squatina californica) captured inciden- 
tally in the artisanal elasmobranch fish- 
ery in the Gulf of California in Mexico. 
A total of 306 Pacific angel sharks (192 
females and 114 males) were analyzed. 
The size of the females ranged between 
23 and 100 cm total length (TL), 
whereas males ranged between 25 and 
99 cm TL. The maturity stages of both 
females and males were determined by 
using the development of internal and 
external organs. The results of analysis 
of covariance reveal a significant effect 
of sex (P<0.001) on length at maturity. A 
binary logistic regression was applied for 
each sex to estimate the length at which 
half of the individuals were consid- 
ered mature (L;)). For females, L;) was 
74.41 cm TL (95% confidence interval 
[CI]: 72.81—76.00 cm TL), and the steep- 
ness coefficient (©) was 1.43 (95% CI: 
0.84-2.42). For males, L;y was 77.82 cm 
TL (95% CI: 75.66-79.97 cm TL), and 
the ® was 3.08 (95% CI: 1.98-4.77). 
The maturity ogive produced by using a 
logistic function is suitable to represent 
the development pattern of this species 
because it describes maturity as a grad- 
ual process. 
Manuscript submitted 28 October 2019. 
Manuscript accepted 30 October 2020. 
Fish. Bull. 118:359-364 (2020). 
Online publication date: 11 December 2020. 
doi: 10.7755/FB.118.4.5 
The views and opinions expressed or 
implied in this article are those of the 
author (or authors) and do not necessarily 
reflect the position of the National 
Marine Fisheries Service, NOAA. 
Length at maturity of the Pacific angel 
shark (Squatina californica) in the artisanal 
elasmobranch fishery in the Gulf 
of California in Mexico 
J. Fernando Marquez-Farias 
Email address for contact author: fmarquez@uas.edu.mx 
Facultad de Ciencias del Mar 
Universidad Aut6noma de Sinaloa 
Paseo Claussen s/n 
Col. Los Pinos 
82000 Mazatlan, Sinaloa, Mexico 
The Pacific angel shark (Squatina 
californica) belongs to the family Squa- 
tinidae and inhabits the eastern Pacific 
Ocean. Its geographical distribution is 
discontinuous: from southern Alaska 
to the Gulf of California (GOC) in Mexico 
and from Ecuador to Chile (Compagno 
et al., 2005). This species is a noctur- 
nal opportunistic predator of demersal 
fish species (Pittenger, 1984; Fouts and 
Nelson, 1999). In California, this spe- 
cies has been found in shallow waters 
at depths of 3-46 m, whereas in the 
GOC it has been observed at a depth 
of 183 m. This species has been found 
buried in muddy and sandy bottoms. 
It also has been observed around rocks 
and in kelp forests (Compagno, 1984). 
The demography of the northern pop- 
ulation off California has been stud- 
ied, and the low productivity of this 
population has been modeled (Cailliet 
et al., 1992). The low productivity of 
this species is consistent with the char- 
acteristics of elasmobranchs that make 
them susceptible to overfishing: late 
maturity, low fecundity, and long life 
(Walker, 1998). 
The capture of Pacific angel sharks 
is mostly incidental in the artisanal 
elasmobranch fishery and the finfish 
trawl fishery both in the GOC and on 
the Pacific coast of the Baja California 
Peninsula (BCP) in Mexico. Biological 
information about the Pacific angel 
shark in Mexico is fragmented and lim- 
ited to a few studies on trophic ecology 
and reproduction (Escobar-Sanchez 
et al., 2006, 2011; Romero-Caicedo 
et al., 2016). Using mitochondrial 
DNA, Ramirez-Amaro et al. (2017) 
reported genetic differences between 
specimens from the GOC and Pacific 
coast of the BCP, validating previous 
observations of life history differences 
between specimens from these areas 
(Villavicencio-Garayzar, 1996). Sim- 
ilarly, Marquez-Farias (2007) found 
maximum lengths and lengths at 
maturity for the population of shov- 
elnose guitarfish (Pseudobatus pro- 
ductus) in the GOC that are different 
from those reported for the popula- 
tion along the Pacific coast of the BCP 
(Villavicencio-Garayzar, 1995). 
Because of its historical exploitation 
rates and vulnerability, the Pacific angel 
shark is classified as near threatened 
on the IUCN Red List of Threatened 
Species (Cailliet et al., 2016). The sig- 
nificant fishing effort in the elasmo- 
branch fishery of the GOC (Bizzarro 
et al., 2007) makes understanding the 
life history and population dynamics of 
this species essential to identification of 
strategies for its future management. 
