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4 pages, 1 figure, 1 table [EN] The diamondback squid Thysanoteuthis rhombus Troschel, 1857 is a large and elusive oceanic squid spe-cies. Here, we provide the first record of the species for the Catalan coast and integrate this finding in the current knowledge of the species in close area [ES] El chipirón volantín (Thysanoteuthis rhombus Troschel, 1857) es una especie de calamar oceánico grande y elusivo. En este trabajo se proporciona el primer registro de la especie para la costa catalana y se discute en el contexto de registros de la especie en zonas cercanas FAFA was supported by an Irish Research Council–Government of Ireland Postdoctoral Fellowship Award (Ref. GOIPD/2019/460) With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)

In this paper, Thysanoteuthis rhombus is first registered in the coast of Pisco and its distribution range in the Eastern Pacific is extended to Ica, Peru. A 68 cm LM specimen was captured between 13°50'00"S and 77°08'00"W at 50 meters depth. A brief description of the species is given, with taxonomic observations and comments on its geographic distribution and fishery., En el presente trabajo a través de la pesca artesanal se registra por primera vez Thysanoteuthis rhombus en el litoral de Pisco y se amplía su rango de distribución en el pacífico oriental hasta Ica, Perú. Un ejemplar de 68 cm LM fue capturado entre los 13°50’00” S y 77°08’00” W a 50 metros de profundidad. Se realiza una breve descripción de la especie, con observaciones taxonómicas y comentarios sobre su distribución geográfica y pesquería.

Mercury (Hg) concentrations have significantly increased in oceans during the last century. This element accumulates in marine fauna and can reach toxic levels. Seafood consumption is the main pathway of methylmercury (MeHg) toxicity in humans. Here, we analyzed total Hg (T-Hg) concentrations in two oceanic squid species (Ommastrephes bartramii and Thysanoteuthis rhombus) of an increasing commercial interest off Martinique, French West Indies. Stable isotope ratios reveal a negative linear relationship between δ15N or δ13C in diamondback squid samples. No significant trend was observed between δ34S values and T-Hg concentrations, contrasting with the sulfate availability and sulfide abundance hypotheses. This adds to a growing body of evidence suggesting Hg methylation via sulfate-reducing bacteria is not the main mechanism driving Hg bioavailability in mesopelagic organisms. All squid samples present T-Hg levels below the maximum safe consumption limit (0.5 ppm), deeming the establishment of a commercial squid fishery in the region safe for human consumption.

Background. The presence of Thysanoteuthis rhombus Troschel, 1857 in the eastern Pacific Ocean was estimated based on the geographic range of the species constructed from scattered locations of adults, juveniles, and egg masses. Goals. This note describes morphometric characteristics of the southernmost registry of the diamond squid T. rhombus in Mexican waters of the Gulf of Tehuantepec (16°N-95°W). Methods. In January 2015 we found a stranded adult female weighing a total of 12.5 kg, with a total length of 92 cm, and a mantle length of 45.5 cm. Results. This was a mature female, with oocytes inside the oviducts that averaged 1.2 mm in diameter, and seven attached spermatophores on the buccal membrane of the female, as evidence of mating. Conclusions. This late registry in the Gulf of Tehuantepec could simply be due to their relative scarcity in the eastern Pacific Ocean.

The feeding ecology and consumption rate of the broadbill swordfish (SWO, Xiphias gladius) from Ecuadorian waters were assessed by stomach content analysis of 256 individuals ranging between 91 and 291 cm in straight fork length (FL). Based on the alimentary index (%AI), the jumbo squid (Dosidicus gigas) was the most important prey species (58.93%AI), followed by bullet and frigate tunas (Auxis spp.) (17.94%AI). Permutational multivariate analysis of variance (PERMANOVA) detected one size-related shift in feeding habits to occur at FL ~ 190 cm, whereas no spatial variations in diet composition were observed. Similarity percentages (SIMPER) analysis revealed that the diet of small SWO (≤ 140 cm FL) and medium SWO (140–190 cm FL) was mainly characterized by Dosidicus gigas (contributing to 50.77 and 66.82% of the similarities, respectively) and Auxis spp. (18.14 and 17.23%, respectively); Auxis spp. and Thysanoteuthis rhombus, however, were the greatest contributors to the similarity in large SWO (≥ 190 cm FL) (47.87 and 22.06%, respectively). The daily meal was estimated to be 468.03–676.78 g day−1, which corresponded to a daily ration of 1.63–8.24% body mass (BM, in g) day−1. The results of this study indicate that the SWO is a mesopelagic predator that plays an important role in structuring the pelagic ecosystem of the Ecuadorian Pacific Ocean.

Individuals in all life stages of the large oceanic diamondback squid Thysanoteuthis rhombus were observed in the southeastern Arabian Sea. A total of 82 individuals were collected from the Arabian Sea between February 2013 and December 2018. The length-weight relationship follows an allometric growth pattern. Age and growth were estimated by statolith increment analysis (n = 77) and demonstrated a rapid growth rate ranging from 1.42 to 4.80 mm dorsal mantle length (DML)/day. Based on back calculated hatch dates, T. rhombus spawned from May to December with a peak in July. Male and female squids matured at 6 months of age. The oldest individual was a mature female (655 mm DML) that was 220 days old with a growth rate of 2.97 mm DML/day. Differences in size-wise (DML) instantaneous growth rates were evident. Stomach content analysis revealed that fish and squid were the major prey of adults and sub-adults, while in juveniles, crustaceans were the dominant prey item. Ontogenetic differences in the diet were apparent.

An egg mass fragment and one paralarva of the squid Thysanoteuthis rhombus found in the Northeastern Tropical Pacific and Gulf of California, Mexico are the first evidence of reproduction of this species in the region. The egg mass fragment was in the disintegration process and contained 30,360 premature hatchlings (96.2%) and 1,192 eggs (3.8%) at different developmental stages. Head chromatophore patterns, buccal crown pigmentation, arm and tentacles indexes, and other morphological characteristics complement previous descriptions of T. rhombus paralarvae. The zooplanktonic community associated with the egg mass was dominated by six species of predatory copepods of the genus Labidocera, Pontella, Oncaea, and Corycaeus which might have actively colonized the egg mass to feed upon the eggs and hatchlings.

Enzymatic solubilization of collagen from the skin tissue of diamond squid Thysanoteuthis rhombus, an underutilized resource in Japan, was attempted using an acid protease from the fungus Rhizopus niveus. This novel approach was compared with the conventional method using porcine pepsin. Both proteases were able to solubilize most of the skin collagen (>90 % of the total collagen) by performing the treatment in 0.5 M acetic acid at 4 °C for 72 h and at an enzyme/substrate ratio (w/w) of 1/10. The SDS-PAGE patterns of the solubilized collagen preparations were quite similar to each other, and two types of collagen (major and minor collagens) were purified from each preparation by cation-exchange column chromatography. These collagen types from the porcine pepsin-solubilized collagen showed similar features to those from the Rhizopus acid protease-solubilized collagen. These results suggest that the Rhizopus acid protease, a protease of non-animal origin, is applicable for solubilizing collagen in the skin of diamond squid.

The occurrence of the diamond squid Thysanoteuthis rhombus in the Colombian Caribbean is recorded for the first time based on one stranded specimen (60 cm mantle lenght) at Morro de Gaira, near Santa Marta.

To elucidate the effects of hydrographic conditions on the migration and distribution of diamond squid (Thysanoteuthis rhombus) in the Sea of Japan, two numerical experiments were conducted using a Lagrangian particle-tracking model. First, Lagrangian simulations with different horizontal swimming speeds were conducted in the area off the San-in coast, the southwest Sea of Japan. The comparison results of simulations and experimental tagging records from 2003 suggest that horizontal movement of diamond squid over a few days is influenced by individual swimming, but long-term migration over more than about 10 days is dependent on the ambient current field. Secondly, further Lagrangian simulations with biological processes, forced by different hydrographic conditions in 2003–2005, were conducted. Temporal variations in distributions and sizes calculated by the model corresponded approximately to those of catch data. A large number of particles simulating squid were distributed over the nearshore region from the San-in coast to the Noto Peninsula during September–November every year. Differences in the migration route and distribution of particles among years were closely related to differences in hydrographic conditions such as the position of the main stream of the Tsushima Warm Current. Prediction of the catch off the San-in coast might be improved by considering hydrographic conditions in the southwest Sea of Japan.

Age, growth and hatching season were estimated for the diamond squid (Thysanoteuthis rhombus) migrating into the Sea of Japan based on analyses of statolith growth increments and length–frequency data of the catch in 1999–2004. Growth rates did not differ significantly between the sexes. The oldest squid was 306 days old, which provides further evidence that T. rhombus has a 1-year life span. The hatching season extended from January to September, with a peak in February–March, and the spawning grounds were suggested to extend from the far southwestern Pacific to the East China Sea. Using aging results from statolith analysis, growth was well described by a logistic formula, which also closely corresponded with the sequential progress of the mean mantle length in size–frequency distribution of the catch. Growth rates varied depending on the time of hatching; earlier-hatched squid grew faster than later-hatched ones, suggesting that the former hatched in warmer upper-stream areas of the Tsushima Current or the Kuroshio region and the latter hatched in colder mid- or downstream areas of the Tsushima Current.

The early life stages of the diamond squid Thysanoteuthis rhombus from early embryogenesis to post-hatching (0 – 7 days old) were observed through laboratory incubation using egg masses collected in the southern Sea of Japan. The egg diameter and mantle length increased during embryonic development through hatching. Mantle-length growth was linear over time, and the growth rate was significantly higher at 258C than at 208C. The inner yolk was located on the dorsal side of the mantle cavity and increased in volume through hatching. Immediately after they hatched, the hatchlings remained on the bottom of culture plates with their ventral sides facing up, but 2– 3 days after hatching they began to swim with their dorsal sides facing up. Feeding experiments were conducted, but none of the hatchlings fed. Statolith growth increments were shown to form daily. Ontogenetic changes that occur from fertilization through post-hatching are discussed.

This paper provides the first evidence that Thysanoteuthis rhombus spawns in the Sea of Japan. Five planktonic egg masses were collected in the southern Sea of Japan during 29 October to 24 November 2004 and transported to onshore laboratories for observation. Part of each egg mass was reared in indoor, aerated tanks supplied with filtered running seawater. The egg masses (ca. 60-120 cm in total length and 13-15 cm in diameter) were cylindrical with rounded ends and consisted of a resilient, transparent gelatinous core with a pair of egg rows forming spiral loops around the core. The embryos had dome-shaped mantles covered with many chromatophores and slowly rotated inside the spherical egg capsules. Hatching was observed in all the egg masses 3-10 days after collection. Morphological characteristics of the egg masses, eggs and embryos, especially the large number of chromatophores present in the early embryonic stages, agreed with the descriptions in previous studies. Near the collections sites, surface water tem- perature and salinity ranged 18-22 °C and 33.3-33.7, respectively, both of which were lower than the optimum conditions for T. rhom- bus spawning. The early embryonic stages of the egg masses at collection such as cleavage and slow currents at the sea surface suggest the egg masses were spawned near the collection sites. Increased abundance of T. rhombus in the Sea of Japan and increased sampling efforts were proposed as two possible causes for the egg-mass discoveries.

We review the fishery for the diamond squid ( Thysanoteuthis rhombus ) in Japan and recent Japanese research conducted on this species. T. rhombus occurs worldwide in tropical and subtropical waters, including near southern and central Japan, where it is targeted by a growing fishery. The annual catch in Japan increased from 339 t in 1989 to almost 6000 t in 2001, and during 1998–2003, averaged close to 4900 t. The main fishing grounds are located in the Sea of Japan, Okinawa Prefecture, and Kagoshima Prefecture, and 90% of the total catch is made in the Sea of Japan and Okinawa. In the Sea of Japan, it is caught with free-floating angling gear called “taru-nagashi” and inshore trap nets; the fishery there usually runs from July to February, with highest catches occurring in September–December. The annual catch in the Sea of Japan during 1998–2003 ranged between 1600 and 3700 t. In Okinawa, it is fished primarily in the daytime with free-floating angling gear called “hata-nagashi”; the fishery there runs mainly from November to April, with highest catches occurring in February–April. The annual catch in Okinawa increased from 15 t in 1989 to 2300 t in 2003. The free-floating egg masses of T. rhombus occur widely in surface waters near southern and central Japan, and paralarval distribution patterns suggest that it spawns over a wide area almost year-round. Part of the population is transported by the Tsushima Current into the Sea of Japan, but little is known about this migration. The vertical distribution of T. rhombus varies regionally; in Okinawa, it occurs mainly at 300–650 m depth during the day and 0–150 m depth at night, while in the Sea of Japan, it occurs mainly at 75–100 m depth during the day and 0–50 m depth at night. Its life span is thought to be about 1 year, and squid larger than 30 cm mantle length grow about 7–10 cm mo −1 .

This paper describes recent catch fluctuations of the diamond squid Thysanoteuthis rhombus in the Sea of Japan and the development of models used to forecast catch per unit effort (CPUE) off Hyogo Prefecture based on statistical analyses of environmental indices measured 600 km upstream in the Tsushima Current. Annual catches during 1989–2002 fluctuated widely, and prefectural annual catches were closely related to each other, especially among the western prefectures. Four indices in June were closely related with CPUE during the fishing season (September–November) off Hyogo: (1) water temperature in the Tsushima Strait, (2) salinity in the Tsushima Strait, (3) sea level at Izuhara (Tsushima Island) and (4) sea level difference between Izuhara and Hakata (Kyushu Island). Using these indices as independent variables, simple and multiple regression analyses were conducted, and CPUE was accurately estimated by both regression and extrapolation, indicating that the CPUE off Hyogo can be forecasted 2 months before the fishery starts using the described models. The strong correlation among catches in different prefectures suggests the indices discussed here affect the catches over a large area.

Third-stage larvae of two species of the genus Anisakis, A. simplex (Rudolphi, 1809) and A. physeteris Baylis, 1923, and those of two types of Lappetascaris sp. are described from four species of squids from the central and western North Pacific Ocean. Larvae of Lappetascaris sp. Type A were 15-33 mm long and occurred individually free in the mantle musculature of squids, whereas those of Lappetascaris sp. Type B were considerably smaller, only 3–7 mm long, and were found in capsules on the stomach wall, each capsule containing up to 50–60 larvae. It is not known whether both larval types are conspecific or belong to two different Lappetascaris species. Anisakis simplex and A. physeteris larvae were found in Onychoteuthis borealijaponica Okada and Gonatopsis borealis Sasaki, and O. borealijaponica, respectively, whereas Lappetascaris sp. Type A and Type B larvae from Thysanoteuthis rhombus Troschel, Ommastrephes bartramii (LeSueur), Onychoteuthis borealijaponica and G. borealis, and O. bartramii, respecti...

6 pages, 2 figures, 1 table.-- PDF of this article is free journal., Eight planktonic egg masses of the diamond-shaped Thysanoteuthis rhombus observed from 1995 to 2000 are described. Four were found in the western Mediterranean and the others were found off the Canary Islands. The egg masses from the Canary Islands are the first records for the eastern Atlantic. All were found near the surface at the end of summer and the beginning of autumn. The planktonic egg masses were dense, resilient oblong cylinders with rounded tips ranging from 80 to 130 cm in length and between 15 and 20 cm in diameter. Egg capsule dimensions ranged from 2.8 to 3.4 mm and total length of the newly hatched paralarvae was between 2.5 and 2.8 mm. Each egg mass contained an estimated 24 100–43 800 eggs. Some new characters that should help identification of the paralarvae, such as arm formulae, presence of an incipient keel-shaped membrane on some arms, and the type and chromatophore pattern are given. Ecological factors influencing the presence and distribution of these egg masses are discussed.

Data on two female individuals of the diamonback squid, Thysanoteuthis rhombus, are presented with discussion of occurrences along the Brazilian coast.

Statolith microstructure was studied in two abundant planktonic cranchiids, Cranchia scabra (56 specimens, 38-127 mm mantle length, ML) and Liocranchia reinhardti (34 specimens, 99-205 mm ML) sampled in epipelagic waters of the western part of the Gulf of Guinea (tropical Atlantic). Growth increments were revealed in ground statoliths of both species. It was possible to dis- tinguish two growth zones in statolith microstructure by their colour in reflected light of the micro- scope: the translucent postnuclear zone and pale white opaque zone. Assuming that growth increments in statoliths were produced daily, ages of the largest immature Cscabra and L.ranhardti were 166 and 146 days, respectively. Both cranchiids are fast-growing squids with growth rates in length resembling those of juveniles of tropical ommastrephids and Thysanoteuthis rhombus. Liocranchia reinhardti grows fasten its growth rate in ML is approximately twice that of same-aged Cscabra.Thc life cycle of both cranchiids consists of two phases. During their epipelagic phase, Oscabra and Lreinhardti feed and grow rapidly from paralarvae to immature young in the epipelagic waters, attaining 120-130 and 170-200 mm ML by ages of 4-5 months, respectively. Then they change their life style to a deepwater phase.

8 páginas, 2 figuras, 1 tabla, Data on opportunistic sightings of diamond-shaped squid Thysanoteuthis rhombus egg masses in the Canary Islands (Atlantic Ocean) are presented. A total of 16 egg masses of this species were recorded and photographed from 2000 to 2010 around the western islands of the archipelago (El Hierro, Tenerife and La Gomera). These data reveal the existence of an important spawning area for diamond-shaped squid around the Canary Islands, in subtropical east Atlantic waters. We provide preliminary data for the potential development of an artisanal fishery focused on this species, and a discussion on its potential impacts on the marine ecosystem., This work has been supported by the project “Cetáceos, Oceanografía y Biodiversidad de las Aguas Profundas de La Palma y El Hierro” funded by the Ministry of Sciences and Innovation of the Spanish Government, grant number CETOBAPH-CGL2009-1311218.

WOS: 000315934300018 This paper presents records extending or confirming the distribution of Mediterranean species. Three alien algae are included, namely Codium taylorii reported for the first time from the Aegean and Turkey (Izmir Gulf), Caulerpa racemosa var. cylindracea (Karpathos and Chalki Isl., Aegean Sea) and Ganonema farinosum (Karpathos Isl., Aegean Sea). As far as animals are concerned, Litarachna divergens (Acari: Hydrachnidia) was recorded (Side, Eastern Mediterranean) and represents a new amendment at genus level for Turkish fauna. Other invertebrates include alien species such as the crabs Dyspanopeus sayi (Lago Fusaro, SW Italy), Percnon gibbesi (Larnaca, Cyprus; Karpathos and Chalki Isl., Aegean Sea) and Callinectes sapidus (Voda estuary, NAV Greece), the nudibranch Aplysia dactylomela (Boka Kotorska Bay, Montenegro), the gastropod Conomurex persicus (Karpathos and Chalki Isl., Aegean Sea) and the bryozoan Electra tenella (Livorno harbour and Messina Straits area). The alien fish Siganus luridus, Siganus rivulatus, Fistularia commersonii, Sphyraena chrysotaenia and Sargocentron rubrum are also reported from the islands of Karpathos and Chalki, and Pteragogus pelycus from Heraklion Bay, Crete. In addition, new localities for four rare Mediterranean inhabitants are given: the cephalopod Thysanoteuthis rhombus (NW Sardinia) and the fish: Lampris guttatus (Calabria, S Italy), Petromyzon marinus (Gokova Bay) and Remora australis (Saronikos Gulf), while the opisthobranch gastropod Cerberilla bernadettae is reported for the first time from the E Mediterranean (Cyprus). Finally, three species of the Aegean ascidiofauna are recorded for the first time: Lissoclinum perforatum, Ciona roulei and Ecteinascidia turbinata. Furthermore, it was established that Phallusia nigra has extended its distributional range to the north of the Aegean Sea. Celal Bayar UniversityCelal Bayar University [FBE 2011/080] The contribution of the following persons is highly appreciated: Prof. Paul C. Silva (Berkeley, USA) and Prof. Michael J. Wynne (Michigan, USA) for kindly providing assistance in the study of Codium taylorii, which was supported by the Celal Bayar University (FBE 2011/080); Giuseppe Urgu for his collaboration and the photographs of the Thysanoteuthis rhombus specimen; Dr. Suat Ate and Dr. Mehmet Cengiz Deval for their assistance, and Andrea Spyrou and Fani Konstantinou for their valuable help in collecting samples of Percnon gibbesi; Spyros Michopoulos for collecting the specimens of Callinectes sapidus; the Cretaquarium aquarists for the fish maintenance and Dr Divanach, Cretaquarium scientific responsible for his collaboration.

The occurrences of Thysanoteuthis rhombus in the Adriatic Sea are critically reviewed and discussed in relation to the records of this cephalopod in the Mediterranean during the last decade.

We determined the sulfation patterns and the amount of chondroitin sulfate in several tissues of the diamond squid, Thysanoteuthis rhombus. Every tissue contained the highly-sulfated E type of chondroitin. The arms, skin, and fin had non-sulfated chondroitin as the homogenous polymer. The skin and fin possessed larger amounts of chondroitin sulfate per unit of weight than the other tissues.

A single male specimen of Thysanoteuthis rhombus was caught using a hand squid jig just after dusk on 26 December 2006, 15 metres offshore Dolfin Islet (44°41′N 14°41′E) at a depth of 10 m in the eastern part of the northern Adriatic Sea. This is the first record of this species in the Adriatic Sea and the northernmost capture in the Mediterranean Sea.

The structure of the reproductive systems of mature males and females of the nektonic, oceanic squid Thysanoteuthis rhombus are described. The main peculiarities of the female system are relatively low capacity oviducts, set in a tight spiral, and hypertrophically developed oviducal glands with a very large second section. The male reproductive system is characterized by a long, narrow Needham's sac containing 10–15 large spermatophores 80–100 mm in length. The mesentery supporting the gonad, and protruding into it dorsally, is a characteristic feature in both sexes. The hectocotylus structure differs markedly from that in other squids and resembles that of sepiids. The reproductive system of T. rhombus possesses primitive features (pattern of gonad attachment and hectocotylus) but mostly secondary characters (small oviducts, very large oviducal glands and ovary). The complex morpho-ecological adaptations of T. rhombus are reflected in the distinctive features of the reproductive system.

WOS: 000183987100005, This study was carried out in northern (Saros Bay) and southern (Gokova Bay) parts of the Aegean Sea. In pelagic samplings, Hamburg Plankton Net (HPN) was used. Samplings were done out at four different periods of a 24 hour day; sunrise, noon, sunset and midnight. Horizontal hauls were carried out at depths of 100, 350 and 650 m. As the result of 24 hauls in both parts of the Aegean Sea, one hundred juvenile specimens were sampled and 14 species were determined. Juvenile cephalopods were mostly frequent at 350 m. Among the determined species, Chtenopteryx sicula (Verany, 1851), Brachioteuthis riisei (Steenstrup, 1882), Illex coindetii (Verany, 1839), Thysanoteuthis rhombus Trochel, 1857 and Argonauta argo Linnaeus, 1798 juveniles are being reported for the first time in the Aegean Sea. 28% of the catches were from the northern Aegean and the remaining 72% were from the southern Aegean. Heteroteuthis dispar (Ruppell, 1844) was the most common species.

Age and growth of the large oceanic squid Thysanoteuthis rhombus were estimated by statolith increment analysis of 72 specimens [mantle length (ML) ranging from 25 to 805 mm] and reproductive biology was studied on 162 T. rhombus (ML 150 to 850 mm) captured in the eastern tropical Atlantic and southwestern Pacific between 1976 and 1990. The maximum ages found in our samples were observed in a mature female of 750 mm ML (305 d) and in a mature male of 770 mm ML (309 d). The life span of T. rhombus was estimated to be about 1 yr; males and females matured at age 6 to 8 mo. T. rhombus is one of the fastest-growing squids: by age 300 d, they reached 750 to 800 mm ML and 17 to 17.5 kg body weight (BW). The increase in both ML and BW during ontogenesis was best fitted by a logistic growth curve. T. rhombus has high potential fecundity (up to 4.8 million oocytes), but a rather small maximum volume of oviducts (up to 140 000 eggs) and egg masses (35 000 to 75 000 eggs). It is suggested that T. rhombus is an intermittent spawner with multiple filling and evacuation of oviducts. The main function of the (for squid) unusual behaviour of T. rhombus, i.e. living in pairs consisting of a male and female, is reproduction and is optimal given the low density of T, rhombus populations and low active movement of squids.

Only one specimen of Architeuthis dux was previously reported from the southern Indian Ocean. The present work adds ten new records of giant squid in the area. Two remains of fresh specimens have been collected from La Reunion Island (218S) and Amsterdam Island (388S) in tropical and subtropical waters, respectively. Eight other squid were identi¢ed from beaks found in stomach contents of sleeper sharks caught in Kerguelen waters (47 to 488S) located in the southern Polar Frontal Zone. These new data together with published and unpublished information on the food of seabirds and marine mammals indicate that giant squid have a wide distribution throughout the southern Indian Ocean. Most records of the giant squid (Architeuthis dux Steenstrup, 1857) come from some localities in the North Atlantic (Newfoundland, northern Europe), South Atlantic (South Africa), New Zealand and the North Paci¢c (Japan). It is thought to be a cosmopolitan species or a complex of species, but, in many parts of the world ocean, either no or a few specimens have been recorded (Clarke, 1966; Roper & Boss, 1982). In the Indian Ocean, except the occurrence of specimens in the diet of sperm whales caught oi eastern South Africa and western Australia (Clarke, 1980), only one giant squid was found stranded on the small oceanic island of Saint Paul in 1874, the so-called A. sanctipauli Velain, 1875 (Species dubium; Fo« rch, 1998). In this note, we report two new observations of speci- mens at sea and the occurrence of beaks of giant squid in the diet of deep-sea sharks from diierent water masses of the southern Indian Ocean. Giant squid were identi¢ed from the morphology of their chitinous lower and upper beaks. Beaks of A. dux have a typical shape, the chitin is thin and lightly coloured, and often the wings and lateral walls curl up (Clarke, 1986). Lower beaks might be confused with those of Thysanoteuthis rhombus Troschel, 1857, but Architeuthis beaks grow to and darken at a larger size (Clarke, 1986). Lower rostrum length (LRL) was measured with a vernier caliper, and dorsal mantle length (ML) was estimated using the allometric equation from Roeleveld (2000). On 18 April 1998, a big chunk of £esh of a large cephalopod including the base of the arms, head and the upper part of the mantle was seen £oating at the sea surface about ten miles from Saint Paul, La Reunion

The egg mass of the diamond-shaped squid, Thysanoteuthis rhombus (Oegopsidae: Thysanoteuthidae) was sighted in surface waters off south-east Sulawesi. It was a sinuous hollow tube-like structure about 2 m long and 0·15 m diameter. It was estimated to contain in the order of 180,000 purple eggs of 1 mm diameter with little or no yolk. Development of the embryos from early differentiation to hatching took between 47 and 57 h at about 28°C.

Free amino acids, trimethylamine oxide, and betaine in the mantle muscle of six species of squids were determined, and interesting facts on the species-difference in the amount of components were observed, as shown in Table 2 and Fig. 1. Squids having a better taste, such as Loligo chinensis GRAY, Loligo kensaki WAKIYA and M. ISHIKAWA, Sepioteuthis lessoniana FERUSSAC, and Sepia esculenta HOYLE, were rich in free amino acids, in which glycine, proline, and alanine were prominent. In some squids inferior in taste, Ommastrephes sloani pacificus STEENSTRUP and Thysanoteuthis rhombus TROSCHEL, trimethylamine oxide was the dominent component with less amount of free amino adid, with single exception in arginine, than the other species of squids. From these facts, such free amino acids, as glycine, proline and alanine are assumed to be responsible for the deliciousness of squids.

3 pages, 1 figure, [EN] Thysanoteuthis rhombus Troschel 1857, has been found for the first time in Spanish waters at Villacarlos (Port Mahón, MInorca), on May 17th, 1978. [...], [ES] Thysanoteuthis rhombus Troschel 1857, ha sido hallado por primera vez en aguas españolas en Villacarlos, puerto de Mahón (Menorca), el 17 de mayo de 1978. El autor tuvo conocimiento de ello y lo identificó un año después. El ejemplar destaca por su considerable tamaño, 130 cm de longitud total, y por su peso, 12,5 kg