Cephalopod reproductive strategies are reviewed in order to clarify their current, confusing status. Based on the type of ovulation, spawning pattern and growth between egg batches or spawning periods, five comprehensive and flexible cephalopod reproductive strategies are defined. Accordingly, with these three factors the following classification is proposed. (a) Spawning once (formerly semelparity) consisting of simultaneous terminal spawning, with synchronous ovulation, monocyclic spawning and absence of growth between egg batches. (b) Spawning more than once (formerly iteroparity) including: (i) polycyclic spawning with egg-laying occurring in separate batches during the spawning season and growth occurring between production of egg batches and spawning seasons; (ii) multiple spawning, with group-synchronous ovulation, monocyclic spawning and growth between egg batches; (iii) intermittent terminal spawning, with group-synchronous ovulation, monocyclic spawning and no growth between egg batches; (iv) continuous spawning, with asynchronous ovulation, monocyclic spawning and growth between egg batches. Examples of species exhibiting each of these reproductive strategies are given. The large amount of inter-species variation in several life-history traits related to reproductive events is discussed.

Cephalopods are of increasing importance as a fishery resource and many species are taken in directed and bycatch fisheries around the world. Owing to the short life-cycles and variable growth rates of most cephalopods, stocks may be highly volatile, both highly susceptible to recruitment overfishing and, conversely, capable of rapid recovery.Many species have protracted spawning seasons so that multiple microcohorts may be present in the population at any one time.Many assessment methods have been applied to cephalopod stocks, including stock recruitment relationships (e.g. the Japanese Todarodes pacificus stock), recruitment indices (e.g. Saharan Bank cephalopod stocks), swept-area biomass estimates (e.g.Northwest Atlantic stocks of the squids Loligo pealei and Illex illecebrosus), production models (e.g, Saharan Bank cephalopod stocks), cohort analysis (e.g. Illex argentinus in the Falkland islands), yield-per-recruit models (e.g. Northwest Atlantic squid stocks), length-based cohort analysis (e.g. Dosidicus gigas in the Gulf of California), and depletion estimates of stock size (e.g. Illex argentinus in the Falkland islands).Despite the widespread application of assessment methods, few stocks are rigorously managed, and the best example of a regulated fishery is the Falkland islands squid fishery. In contrast, although a number of assessment methods are used in the Japanese Todarodes fishery, management activities arc designed to ensure harmonious operation of the industry rather than maintain stock size. Fisheries for Loligo forbesi and Loligo vulgaris in the Northeast Atlantic arc mainly based on by-catches, although there is some directed fishing, particularly artisanal jig fishing in coastal waters. There is currently no assessment and minimal management for these species, and available management options are constrained by the nature of the fishery and the generally poor quality of available data.

The Atlantic Ocean-Mediterranean Sea junction has been proposed as an important phylogeographical area on the basis of concordance in genetic patterns observed at allozyme, mtDNA and microsatellite DNA markers in several marine species. This study presents microsatellite DNA data for a mobile invertebrate species in this area, the cuttlefish Sepia officinalis, allowing comparison of this relatively new class of DNA marker with previous allozyme results, and examination of the relative effects on gene flow of the Strait of Gibraltar and the Almería-Oran oceanographic front. Genetic variation at seven microsatellite loci screened in six samples from NE Atlantic and Mediterranean coasts of the Iberian Peninsula was high (mean Na = 9.6, mean H e = 0.725). Microsatellites detected highly significant subpopul-

Reproductive and energy allocation analyses were performed on 1418 common octopus (Octopus vulgaris) from the Galician creel fishery (NE Atlantic) between May 2000 and December 2005. Individuals ranged from 8 to 35 cm dorsal mantle length (DML) and 136-6303 g body weight (BW). The length-weight relationship for whole animals was BW = 2.9(±1.1) × DML 2.17(±0.04) (r = 0.86; P < 0.00001). The sex ratio only differed from 1:1 during May and September. Spawning of O. vulgaris in this area extends from December to September with a unique peak in spring months. Size-at-maturity was 1788 g for females (n = 508); and 903 g for males (n = 467). Mean (±S.D.) potential fecundity was estimated at 221,447 ± 116,031 oocytes and mean oocyte length at 3.0 ± 0.8 mm. The mean number of fully developed spermatophores was 182 ± 88 with mean length of 48.8 ± 10.6 mm. Potential fecundity was significantly correlated with length and weight in both sexes. The condition (digestive gland to body weight ratio) of females increased proportionally with maturity stage and mature individuals had higher gonad investment suggesting that energy for gonad growth was derived from the diet rather than endogenous reserves. On the other hand, mature males showed poorer condition. The general picture of the reproductive biology of this species in Galician waters is discussed taking into account the seasonal wind-driven upwelling that governs this ecosystem.

The population biology of Loligo vulgaris and Loligo forbesi in Galician waters is described based on monthly samples from the fishery obtained during the period February 1991-June 1992. Maturity was assessed using a maturity scale and indices.The estimated number of oocytes in mature females varied from 782 to 21 885 in L. vulgaris and from 1317 to 14 956 in L. forbesi, and showed a slight positive correlation with the length of the mantle (ML) for both species. Oocytes in the ovaries fall into three discrete size classes, which suggests that L. vulgaris and L. forbesi are intermittent or multiple spawning species. In L. vulgaris males mature at two different modal sizes, hence perhaps at two different ages, while in L. forbesi this occurs in both males and females. Males mature earlier in the season than females in both species. The maximum number of spermatophores found was 1010 and 1000 in two L. vulgaris males with 119 mm and 400 mm ML respectively, and 1035 in a L. forbesi male with 150 mm ML. In both species, spermatophore length increases with ML. Loligo forbesi males maturing at a larger size produce fewer but larger spermatophores than those maturing at a small size. Loligo vulgaris spawn throughout the year, but the period of more intensive spawning extends from December to April. The breeding season of L. forbesi extends from December to May, the more intensive spawning extending from December to February. Sex ratios were variable for both species. Age and growth for both species and sexes were estimated by examining growth increments in the statoliths. Like-sized individuals had different ages in both species. The life span of L. vulgaris was estimated at about l year while L. forbesi seems to reach an age of 15-16 months. A list of prey species found in gastric contents of both species is given. The diet of L. vulgaris comprises fish (86.8%), cephalopods (6.0%), crustaceans (3.0%) and polychaetes (1.8%), and the diet of L. forbesi includes fish (75.6%), crustaceans (18.5%) and cephalopods (4.4%).