Age structure and hatchling dates of the squid Illex argentinus collected by bottom-trawl fishery in southern Brazilian waters were assessed by the analysis of statolith growth increments. Catches occurred between 2001 and 2002, from 23° to 32°S at depths of 100–700 m. Squid from juvenile to post-spawning stages were collected year round, with age estimated from 98 to 320 days and mantle lengths ranging from 112 to 376 mm. Duration of life cycle events based on statolith growth zones revealed that squids can spend about 14% of their lifespan as paralarva (~30 days), 70% as juvenile (~130 days), leaving maturity and spawning condition to the terminal 10–20% (~30–60 days). The results suggest that, unlike estimates available for Patagonian populations, a general 0.5 year lifespan is predicted for I. argentinus off Brazil. The wide range of size-at-ages implied that catches of shortfin squid off southern Brazil probably include squid hatched throughout the year. Mature and spawning squid caught in summer months hatched in winter and spring, while winter catches revealed mature-spawning individuals hatched both in summer/autumn (~6 months of age) and winter/spring periods (~10–11 months of age). It has been argued that such groups may combine both squid resident of Brazilian outer shelf and slope (22°–34°S) with a six months' lifespan and migrating squid originated from the northern Patagonian shelf (~42°S) with 10–11 months' lifespan.

The reproductive cycle of the deep-sea eel Nettastoma melanurum was described based on 397 specimens (171 males and 226 females). Experimental trawl surveys between depths of 772 and 1598 m and commercial hauls (580–600 m) on compact mud bottoms off the south-eastern Sardinian waters (central-western Mediterranean) were carried out. The Sardinian catches did not indicate any particular trend of size-range in relation to depth in both sexes and seem to be sexually dimorphic with females growing almost 9 cm longer than males at maximum lengths. It was a dioeceous and an oviparous deep-sea species. For females and males, six stages of oocyte development, characterizing the different stages of maturity, were identified. Histological examination demonstrated that ovaries of N. melanurum showed a ‘group-synchronous’ pattern, highlighting a type of monocyclic ovary. The species showed a size at first maturity of 53.5 cm and 50.5 cm total length in females and males respectively. The reproductive period appeared to be unique and well defined in both sexes. Their monthly changes of gonadosomatic index and maturation phases of ovaries and testis showed that the species was in a resting period from March to July. Vitellogenesis and spawning began in September and ended in January. Nettastoma melanurum seemed to be a fecund species (8132–18755 eggs).

Sperm ultrastructure in two species of the marine snail family Olividae is examined. Euspermatozoa of both species are composed of a conical, membrane-bound acrosomal vesicle; an axial rod and a basal plate similar in both species; a solid and highly electron-dense nucleus; an elongate midpiece consisting of the axoneme sheathed by helical mitochondrial elements; an elongate glycogen piece; a double electron-dense ring at the junction of the midpiece and glycogen piece; and a free tail region. The slight narrowing in the acrosomal vesicle invagination is situated in different levels between Olivancillaria deshayesiana and Olivancillaria carcellesi. This morphology could be considered as a specific character. The length of the nucleus in O. carcellesi and in O. deshayesiana is shorter than that of other neogastropods, and could be diagnostic at family level.

Testes and ovaries of Enteroctopus megalocyathus collected along the Patagonian Atlantic coast were analysed histologically to validate the macroscopic maturity scales adopted for this species. Changes through the course of development of the seminiferous tubules and of the oocyte/follicular cell complexes were characterized and these were classified into five and six microscopic categories of development respectively. A histological maturity index, based on the frequencies of microscopic categories, was used to assess the correspondence between macroscopic maturation stages and the microscopic level of development of the gonadal tissue. Seminiferous tubules showed a regular and progressive pattern of microscopic development within each macroscopic stage and between consecutive macroscopic stages. However, a minority of males exhibiting seminiferous tubule with sperm did not display macroscopic characteristics of the mature-spawning stage. In females, an overlapping of microscopic categories was observed in maturing macroscopic stages. Previtellogenic oocytes were not present at mature-spawning or spent stages. Significant changes in the histological maturity index were observed between consecutive macroscopic stages, confirming the validity of macroscopic maturity scales of both sexes. In addition, by considering both macroscopic and microscopic criteria, it was possible to determine the overall state of development and functioning of the reproductive system during sexual maturation of this species.

A total of 209 strandings of sea turtles (152 loggerhead turtles Caretta caretta, 42 green turtles Chelonia mydas, 15 unidentified) were recorded during the period 1984–2011 along the coasts of Rhodes (Aegean Sea, Greece). The proportion of dead to live individuals was different in the two species. Stranded Caretta caretta were larger than Chelonia mydas. The size range of stranded green turtles, usually juveniles, appeared to increase since 2000, including the largest specimens ever observed in Greek waters. For both species, a tendency to strand more frequently on the west coast of the island, along fishing ground areas, was noted. The higher incidence of loggerhead turtle strandings was observed in summer, while more green turtle strandings were documented in winter. Factors involved in the increased trend of stranding records of both species, along with the acceleration of this phenomenon in the last decade, are discussed. Data from Rhodes provide evidence that human activities detrimentally affect mainly larger-sized loggerhead turtles living in shallow waters.

In this paper, information is presented on green turtle (Chelonia mydas) nesting on Atol das Rocas (Rocas Atoll), north-eastern Brazil. The temporal distribution of nesting events per season, annual number of nests, carapace length of nesting females, clutch size, hatching success, incubation period, internesting interval, clutch frequency, observed reproductive lifespan, and remigration period are reported. The study period included the nesting seasons from 1990 to 2008, but no regular beach monitoring was carried out in 1998 and 1999. Two sorts of methods were applied to the estimation of the annual number of nests in some seasons. Taking into account the estimated annual numbers of nests, the mean annual number of nests in the study period, excluding 1998–1999, was 335 (standard deviation = 139, range = 136–563, N = 17). An analysis of the available data indicates that the average nesting levels at the beginning of the study period (the first five seasons) and at its end (the last five seasons) were roughly the same. The mean curved carapace length of the nesting turtles decreased significantly during the study period, from 115.9 cm in 1990–1992 to 112.9 cm in 2006–2008. Atol das Rocas was established as a federal biological reserve in 1979, but regular sea turtle conservation activities actually started there in 1990. Since that year, the killing of nesting turtles has ceased, nesting activity by the turtles can proceed in an undisturbed fashion, and their clutches can incubate in a protected environment.

Based on the samples collected in Chinese scientific surveys off the Costa Rica Dome from July to August in 2009, statolith microstructure of the jumbo flying squid, Dosidicus gigas, was analysed for studying their age, growth and population structure. Three typical growth zones (postnuclear, dark and peripheral zones), abnormal increments (checks) and aberrant microstructure (additional centre and additional rings) were found in the statoliths examined. Squid sizes ranged from 205 to 429 mm dorsal mantle length (ML) with ages no more than 10 months for females and 8 months for males. Back-calculated hatching dates were from November 2008 to April 2009. Growth in ML was best described by a linear function for both the sexes, while growth in body weight was best quantified by an exponential function for females and a power curve for males. The maximum absolute daily growth rates and instantaneous growth rate in ML were reached during 181–210 and 151–180 days for females and males, respectively. The Costa Rica Dome and its adjacent waters were considered as a potential spawning ground because of presence of not only high proportion of mature squid but also rhynchoteuthion paralarvae, and high primary productivity from the strong upwelling. This study suggests that D. gigas have complicated intra-specific population structure and large spatial variability in the key life history parameters.

First investigation on the relationship between reproductive development and estimated age/size in a wild population of Octopus vulgaris was performed in the Sardinian waters (central western Mediterranean Sea) in order to have a useful tool for integral fishing management in the area. Full sexual maturity was registered from April to August for females with a peak in summer whereas for males it was observed all year round. Size at maturity was 320 g for males (70 mm dorsal mantle length (ML)) and 520 g for females (120 mm ML). From 61 to 465 and from 80 to 390 daily growth increments were counted on the lateral wall of the upper beak, respectively in males and females, obtaining a positive relationship between estimated age and size of the specimens. The sexual maturation was primarily size-dependent with a secondary role played by the age especially in males. The estimated age of 390 and 465 days respectively of the largest female (4661 g) and male (5344 g) as well as that of two males at the end of their lives (‘spent’) of 310 and 420 days old, have suggested a lifecycle of about 1 year for both genders.

Saona Island hosts the last hawksbill turtle (Eretmochelys imbricata) nesting population in the Dominican Republic, which has experienced a severe decline in the last decades, mostly due to illegal egg take. Here we present the results of an artificial incubation programme started in 2007 to protect the clutches from human predation. A preliminary survey in 2006 showed that about 60% of clutches laid were taken by humans. Over the study period (2007–2010) we recorded 400 clutches, of which 38.2% were predated by humans, 40.7% were artificially incubated and 21% were incubated in situ. Overall, the artificial incubation programme allowed the release of 12,340 hatchlings. No differences were found in hatching and emergence success between clutches incubated in situ and clutches artificially incubated. However, incubation temperatures and incubation durations recorded suggest a male-biased hatchling sex-ratio in artificially incubated clutches. Although artificial incubation may mitigate the effect of egg take, our results indicate that other measures, such as clutch relocation to protected sections of the beach should be taken. Beach patrolling and education are currently implemented so that artificial incubation will be eventually phased out in favour of in situ incubation.

A total of 208 Rondeletiola minor were sampled from the eastern Mediterranean with the depth contours of 150, 350 and 550 m. Body sizes of 32 mature females ranged from 11.8 to 19.5 mm dorsal mantle length (ML), that of mature males were 11.1–19.1 mm ML. Potential fecundity varied between 192 and 315 eggs in maturing females, and ripe egg sizes were 1.1–3.0 mm. Ripe egg amount did not exceed 15% of the fecundity. The average number of spermatophores was 176 with two extreme individuals that had 557 and 674 spermatophores, respectively. Spawning occurs continuously with an asynchronous ovulation pattern. Mature animals were found throughout the year with a peak in gonadosomatic index in spring. The life cycle of R. minor was estimated to be 10 months with different cohorts in reproduction depending on how temperature affects the hatching.