398 
Fishery Bulletin 111(4) 
Table 2 
Oocyte histological characteristics of Black Anglerfish ( Lophius budegassa ) collected between June 2007 and December 2010 
in the northwestern Mediterranean Sea; descriptions follow those of Wallace and Selman (1981). Mean oocyte diameters, 
which were measured to the nearest 0.01 pm, are provided by developmental stage with standard errors of the mean (SE). 
Oocyte developmental 
Oocyte 
stage 
diameter (pm) 
Histological characteristics 
Chromatin nucleolar 
36.55 (SE 21.27) 
Nucleus contains a large nucleolus and some small peripheral nu- 
cleoli. Yolk granules are not present in the cytoplasm. 
Perinucleolar 
110.78 (SE 62.54) 
Nucleus grows and several big peripheral nucleoli and vacuoles are 
present. No yolk granules are present in the cytoplasm. 
Cortical alveolar 
256.35 (SE 80.81) 
Nucleus is central. Cortical alveolar vesicles and oil droplets ap- 
pear in the cytoplasm. Yolk granules are still not present in the 
cytoplasm. 
Primary vitellogenic 
364.54 (SE 37.31) 
Yolk granules appear between cortical alveolar vesicles. Nucleus 
remains central. 
Secondary vitellogenic 
406.20 (SE 39.60) 
Yolk granules fill the cytoplasm. Nucleus is still central. 
Tertiary vitellogenic 
544.55 (SE 185.49) 
Yolk granules are in contact with the nucleus, which is still central, 
and the oocyte size has increased from size at previous stages. 
Migratory nucleus 
883.42 (SE 153.33) 
Yolk granules and oil droplets start to fuse. Nucleus migrates to one 
pole of the oocyte. 
Hydration 
1125.09 (SE 176.93) 
Yolk granules form a single mass. Nucleus is not present in the 
cytoplasm. 
and fish length and weight; therefore, large spawners 
have a higher contribution to egg production than do 
smaller ones. Previous authors have found lower fecun- 
dity values than the ones observed in this study. In the 
Tyrrhenian Sea, Carbonara et al. (2005) determined 
mean potential fecundity as 54,057 oocytes per kilo- 
gram of mature female and total fecundity as 211,687 
oocytes from data obtained from a single individual (59 
cm TL). In the case of the Aegean Sea, where fecundity 
values varied from 105,800 to 284,200 oocytes, fecun- 
dity was determined from an undefined number of in- 
dividuals and size range (Tsimenidis, 1980). 
Another relevant feature of the reproduction of Black 
Anglerfish is the presence of a gelatinous matrix, which 
has been noted for other Lopliius species (Armstrong et 
ah, 1992; Fulton, 1898; Leslie and Grant, 1990; Yoneda 
et al., 2001). The matrix consists of individual cham- 
bers where hydrated oocytes are released. In our study, 
we detected the presence of 2 or 3 eggs in some cham- 
bers (Fig. 2). This phenomenon also has been described 
for Goosefish, and it has been assumed that such eggs 
in that species may have been fertilized (Armstrong et 
al., 1992; Everly, 2002). Trippel et al. (1997) concluded 
that for the same species, larger eggs have a higher 
probability of hatching and of subsequent larval sur- 
vival than do smaller ones. It is unknown whether the 
smaller eggs of Black Anglerfish that share a chamber 
hatch at a different rate or produce less viable lar- 
vae than the larger eggs that are alone in a chamber. 
Finally, the semicystic kind of spermatogenesis has 
been described only once before in the family Lophi- 
idae, for Blackmouth Angler ( Lophiomus setigerus) 
(Yoneda et al., 1998a). Munoz et al. (2002) reported 
that semicystic spermatogenesis may be related to the 
secretion of abundant, thick seminal fluid, the function 
of which is to keep the spermatozoa together to enable 
fertilization of the entire egg mass. 
The variation in spawning seasonality of Black An- 
glerfish between spring (La Mesa and De Rossi, 2008) 
and winter (Carbonara et al., 2005; Duarte et al., 2001; 
Tsimenidis, 1980) may be associated with local oceano- 
graphic features. Eddies and fronts enhance productiv- 
ity, often function as physical barriers that retain lar- 
vae and juveniles, and provide favorable conditions for 
the feeding behavior of recruits and their subsequent 
transport toward the main nursery areas (Sanchez and 
Gil, 2000). During spring and summer, temporary ed- 
dies are generated in the Adriatic Sea (Mediterranean 
Sea) and in the Bay of Biscay (Atlantic) (Artegiani et 
al., 1997a, 1997b). In contrast, in wintertime eddies 
are generated in the Aegean and the Tyrrhenian seas, 
and the northern component of the outflow water from 
the Mediterranean Sea influences the Atlantic Iberian 
coast (Iorga and Lozier, 1999). 
Finally, maturity sizes between individuals off the 
Atlantic Iberian coast, 53.6 cm TL in females and 38.6 
cm TL in males (Duarte et al., 2001), and individuals 
in the northwestern Mediterranean Sea, 48.2 cm TL 
