Search

The cannonball jellyfish Stomolophus meleagris display colour variations from blue to purple, and different pigmentation patterns on the umbrella surface. Although these colour phenotypes are commo...

Pigments are present in a broad variety of terrestrial and aquatic organisms. The cannonball jellyfish (Stomolophus sp. 2) is an important fishery resource in the northwest of Mexico and is processed to be traded and consumed as seafood. During the process, water with a soluble blue pigment and other compounds are discarded to the environment. In this work, we present some properties of the blue pigment from Stomolophus sp.2 (S2bp), to decide if it could be considered as a potential value-added waste and avoid the blue proteinaceous pigment wastewater. S2bp was purified to homogeneity and had a molecular mass of 28.0 kDa; this protein exhibited a ʎmax at 650 nm, contained Zn2+ and Cu2+ metal ions, and was stable from 10 to 50 °C and in a pH range of 3.0 to 13.0 for 1 h. It had halotolerant characteristics maintaining the blue coloration in a broad range of ionic strength (0–4 M NaCl) and showed changes in ʎmax with chaotropic salts. In addition, S2bp was stable in the presence of organic acids and EDTA and in zwitterionic, anionic, and nonionic detergents at critical micellar concentration. However, oxidant reagents like NaClO and H2O2 decrease the coloration. These results show that the jellyfish pigment is a stable protein which makes it an alternative pigment for the food industry.

Exploitation of the cannonball jellyfish (Stomolophus sp. 2) is increasing in Mexico and USA due to successful fisheries associated with seasonal blooms in coastal areas. Previously, it was proposed that such blooms could be identified by recognizing the presence of young stages in the water. In our work, we aim to describe the young stages (ephyra and metaephyra) found in the Las Guásimas lagoon, Sonora, Mexico. The description of specimens is based on photographs, drawings, and morphological measurements aimed at helping in the early detection of blooming events.

Loggerhead sea turtles (Caretta caretta) are opportunistic carnivores that feed primarily on benthic invertebrates and fish. Sea turtle rehabilitation requires provision of a species-specific, balanced diet that supplies nutrition similar to that of a wild diet; this can be challenging because free-ranging loggerheads' diets vary depending on their life stage and geographic location, with predominant prey species dictated by local availability. The goal of this study was to better understand the nutritional needs of subadult and adult loggerheads in rehabilitation. This was accomplished by conducting a retrospective survey of stomach contents identified during gross necropsy of 153 deceased loggerheads that stranded in coastal Georgia, USA. A total of 288 different forage items were identified; the most frequently observed prey items belong to the subphylum Crustacea (N = 131), followed by bony fish (Osteichthyes; N = 45), gastropod mollusks (N = 40), bivalve mollusks (N = 23), and Atlantic horseshoe crabs (Limulus polyphemus; N = 15). The proportions of certain prey items differed significantly with turtle size; adult turtles ate proportionately more gastropods (p = 0.001), and subadults ate proportionately more fish (p = 0.01). Stomach contents information was used to determine common local prey items (blue crab, cannonball jellyfish, horseshoe crab, whelk), which were evaluated for nutritional content. Additionally, we compared hematology and plasma biochemistry profiles (including proteins, trace minerals, and vitamins) between four cohorts of loggerhead turtles, including free-ranging subadults and adults, nesting females, and loggerheads undergoing rehabilitation. This information was applied to inform a regionally specific, formulated diet for tube feeding, and a supplement containing vitamins and minerals for captive loggerheads, to more closely approximate the nutritional content of their natural diet. Assessing the regional and temporal variability in loggerhead diets is an important component in their effective conservation because resultant data can be used to help understand the impacts of environmental perturbations on benthic food webs.

The digestive capacity of jellyfish has barely been studied because of the complexity of their life stage body-forms and sizes. To assess the digestive capacity in the changes from the benthic polyp-form to the pelagic stage in the cannonball jellyfish Stomolophus meleagris, we used fluorometric and spectrophotometric techniques for measuring the activity of trypsin, chymotrypsin, aminopeptidase, amylase, lipase, phosphatase acid, and alkaline. The findings showed that at all stages were able to digest proteins, carbohydrates, and lipids, but the digestive capacity differs between the benthic–pelagic stage and final development of the ephyrae, suggesting a shift in nutrient requirements. The digestive capacity indicated that polyps better assimilate carbohydrates and proteins. During the pelagic stage, a shift in the digestive capacity occurred, where 5-day ephyrae better assimilate proteins, while 15-day-old ephyrae were better with lipids and proteins and juvenile medusae with lipids. This is the first study to describe changes in the digestive capacity of cannonball jellyfish and can help identify ecological features of an important fishing resource with potential aquaculture interest. Different diets for polyps, ephyrae, and juvenile medusae must be considered if the species is cultivated.

Cannonball jellyfish, often commercialized as salted, dried jellyfish (SDJ), is an emerging fishery in the USA and a great source of collagen, which can be utilized for developing novel marine gelatin powders. The aim of this study was to determine the feasibility of producing gelatin powders with gelling properties from SDJ using a mild acid hydrolysis and freeze-drying procedure as well as to evaluate their physico-chemical properties. The findings revealed that the resultant gelatin powders had a moisture (g/100 g, dry basis, d.b.), crude protein (g/100 g, d.b.), ash content (g/100 g, d.b.) and water activity values of 4.82, 29.54, 56.61, and 0.09, respectively. Sodium, Al, and S were the main minerals detected in the jellyfish gelatin powders, which were agglomerated and had irregular morphologies with a mean particle size of 12.8 μm. Gels prepared with 5, 6.67, and 10% (w/v) jellyfish gelatin powder had Bloom values lower than 4.2 g; melting temperatures between 15.09 and 16.12 °C and their rheological behavior was effectively characterized by the Herschel-Bulkley flow model, which revealed non-Newtonian behavior and shear thinning phenomena. Higher apparent viscosities, yield stress, and consistency index values were observed in the gels prepared at higher concentrations of jellyfish gelatin powders and at lower evaluated temperatures. This study illustrates (for the first time) the feasibility of producing novel marine gelatin powders from SDJ, which have the potential to be used as gelling, thickening and/or binding agents in several food applications.

The trajectory of the cannonball jellyfish (Stomolophus sp. 2) fishery in the central portion of Mexico’s Gulf of California is an all too familiar one, consisting of exploration, rapid development, and, as of now, subsequent collapse. As all of the product is exported to markets overseas, buyers have little incentive to conserve local stocks, with jellyfish now exhibiting a global-scale sequential exploitation experienced by many other marine resources. While historical data gaps are often used as excuses for overexploitation after the fact, the emergence of this modern fishery was accompanied by relatively broad research interest; however, recommendations based on sound science were not followed. The resultant paucity of policy goals, regulation, cooperation, compliance, and enforcement has resulted in the mismanagement of a potentially lucrative fishery for future generations. There are always myriad challenges when attempting to manage a nascent fishery with high uncertainty, particularly in a developing country, and this case further highlights the importance of taking a precautionary approach to emerging resource extraction. Multiple prior experiences with similar outcomes should behoove regulators and managers to exhibit extra caution, and yet, sustainability and forethought still appear to be secondary to short-term profits and employment support. Nonetheless, it is perhaps not too late for cannonball jellyfish fisheries in the Gulf of California, and there are opportunities to implement management strategies that promote collaboration, research, and sustainability. This fishery requires a new management regime that embraces adaptive co-management in order to provide benefits to locals, both now and in the future.

espanolEl objetivo de esta investigacion fue conocer el rol de los actores involucrados en la pesqueria de medusa bola de canon, en Guaymas, Sonora. Con el metodo bola de nieve se realizaron entrevistas semiestructuradas, luego se jerarquizaron mediante la red de poder/ interes de cuatro cuadrantes, y se relacionaron con una matriz de vinculacion. El resultado arrojo que el Instituto Nacional de Pesca, los compradores, procesadores, comercializadores y las cooperativas pesqueras son los actores clave, con mayor interes e influencia en el manejo de la pesqueria. El presente analisis es util para establecer y mejorar el manejo de la captura de medusa. Se concluye que existe una relacion conflictiva y de poca cooperacion entre los actores mencionados, lo cual impide que se respeten las estrategias de manejo para explotar la medusa en condiciones de sustentabilidad. EnglishThe aim of this research was to know the role of stakeholders involved in the cannonball jellyfish fishery in Guaymas, Sonora. Using the snowball method, semi-structured interviews were conducted, then hierarchized through the power / interest network of four quadrants, and related to a connection matrix. The result showed that the National Fishery Institute, buyers, processors, marketers and fishing cooperatives are the key players, with greater interest and influence in the management of the fishery. This analysis is useful to establish and enhance the management of jellyfish catch. It follows that there is a conflictive relationship and little cooperation among the said stakeholders, which prevents management strategies to exploit jellyfish fishing in conditions of sustainability from being respected.

Cannonball jellyfish has become the target of an important seasonal fishery in the Gulf of California. Research has focused mainly on biological and management aspects, yet linkages and dynamics between social and ecological components have received less attention. Based on an analysis of stakeholder perceptions and its comparison with available quantitative data, this study provides a holistic view of the fishery and its actors as part of a complex adaptive system. Stakeholders include artisanal fishers, owners of improvised and permanent processing plants, foreign buyers and funders, local managers, Mexican management entities, women, and Indigenous communities. Policy guidelines and management actions must address sustainability within various dimensions as understood by those interviewed: social equity, economic benefits, and environmental responsibility. To transition to sustainability, a transdisciplinary research approach is needed to provide management advice and to strengthen fishery governance through co-management decision-making strategies.

Jellyfish are non-model organisms that have brought the scientific community's attention over the last decades since the frequency and intensity of these species blooms around the world have increased significantly. The occurrence of blooms has been hypothesized due to the rise in seawater temperature associated with climate change. This fact has promoted an increased interest in studying jellyfish metabolic responses to face thermal stress and maintain cell homeostasis. In this study, the response of the cannonball jellyfish Stomolophus meleagris to short-term exposure to different temperatures was evaluated. The survival and respiratory rates, and the concentration of glucose, L-lactate, glycogen, ATP, and total soluble protein in the umbrella of adult jellyfish were measured. Low survival rates at extreme temperatures (18 and 33 °C) and an increase in the jellyfish respiratory rates were observed as seawater temperature raised. Rapid changes were detected in energy substrates such as glucose and glycogen that significantly varied at extreme temperatures and longer exposure periods. L-lactate levels increased after 2 h of exposure, and then remained steady at longer times of exposure. Soluble protein concentration decreased significantly in jellyfish exposed to extreme temperatures, and ATP increased after exposure to non-optimal temperatures (18, 28, and 33 °C). These results suggest that S. meleagris faces temperature changes through rapid metabolic responses that use energetic reserves, activate anaerobic metabolism, and display a remarkable ability to synthesize ATP and maintain energy, even at long exposure.

The digestive system and metabolism of the cannonball jellyfishStomolophussp. 2 are not well-known. The digestion study was critical to explain its ecology and bloom success. Different enzymes are involved in food digestion, which hydrolyze carbohydrates, proteins, and lipids. This study detected lipolytic activity in enzymatic extracts from gastric pouches ofStomolophussp. 2 collected in the summer of 2013 at Bahía de Kino, Sonora, México (28°47′47″N 111°57′25″W). Lipase/esterase activity showed optimal pH at 11.0 and 50–60 °C with a half-life (t1/2) of 33 min at 55 °C, whereas halotolerance of this activity was recorded from 0-4 M NaCl. Metal ions Ca2+and Mn2+did not affect the activity, but Mg2+decreased it 14.2% ± 3.15, while chelating agents as ethylenediaminetetraacetic acid reduced the activity 8.55% ± 2.13. Inhibition of lipase/esterase activity with tetrahydrolipstatin and paraoxon-ethyl decreased the activity 18.2% ± 2.3, and 62.80% ± 0.74, respectively, whereas phenylmethanesulfonyl fluoride (a protease inhibitor) did not affect it. The enzyme displayed a higher specificity for short-chain triglycerides, but triolein, coconut oil, olive oil, and fish oil were hydrolyzed. For the first time, phospholipase activity from the gastric pouch ofStomolophussp. 2 was detected using L-α-phosphatidylethanolamine from chicken egg yolk as a substrate. These results suggest thatStomolophussp. 2 hydrolyze several kinds of lipids, and lipolytic enzymes are active at alkaline pH under different saline conditions, which may be essential to digest different preys.

Stomolophus meleagris (Cannonball Jellyfish) is a common Cnidarian species in the coastal waters of Georgia. Libinia spp. (spider crab) juveniles commonly inhabit the bell of the Cannonball Jellyfish, but there is uncertainty as to whether the crabs are parasitic on the Cannonball Jellyfish or are commensals. To assess the nature of this symbiosis, Cannonball Jellyfish were randomly sampled at multiple sites along the Georgia coast. For each Cannonball Jellyfish, the number of juvenile spider crabs inhabiting the bell was recorded along with multiple measurements of Cannonball Jellyfish and spider crabs. Our results suggest that the symbiosis between the Cannonball Jellyfish and juvenile spider crabs is an example of commensalism and not parasitism.

This study describes the first record of the whale shark Rhincodon typus association with the cannonball jellyfish Stomolophus meleagris in the Gulf of California, Mexico. Whale sharks were observed swimming and feeding among swarms of jellyfish, suggesting competition and predatory behaviour given the overlap in food preferences between both species. This finding is relevant because of the species-wide distribution and the importance of these interactions, which should be considered in conservation strategies of R. typus and management of cannonball jellyfish fisheries.

The diet and feeding pattern of scyphomedusa Stomolophus meleagris (Rhizostomeae) was studied, by comparing stomach samples from different developmental stages and environmental zooplankton with the aim to determine diet composition, trophic niche breadth, selectivity and feeding overlap of this edible jellyfish species. Samplings were performed during April and December 2010 and in January 2011, in the coastal lagoon Las Guásimas (27°49′–27°54′N 110°40′–110°35′W), central Gulf of California, which consisted of zooplankton tows and jellyfish collections for stomach content. More than 39 prey items were identified in the gut contents (N = 69), from which eight taxa formed over 90% of the total. Fish eggs were considered main prey (58.6%), copepods (10.8%), veliger larvae of gastropod (13.0%) and bivalve (12.7%) were secondary prey while cirriped and decapod larvae were incidental prey (S. meleagris is a specialist predator and Pearre's index showed positive selection of fish eggs, gastropods, bivalves and cirripeds while selectivity was negative for copepods and appendicularians. The relative timing of these changes suggests that ontogenetic processes are closely related with shift in the diet, which indicates increasing predation pressure during development of the medusoid stage of this species, thus emphasizing their ecological importance in coastal ecosystems.

Studies have been conducted in Georgia to examine bycatch in many fisheries, but none has focused on the trawl fishery for cannonball jellyfish Stomolophus meleagris. Although this fishery is relatively new, it presently ranks in the top three by weight (kg) in Georgia, along with the food shrimp and blue crab Callinectes sapidus fisheries. The purpose of this study was to characterize and quantify the finfish and invertebrate bycatch species in the cannonball jellyfish trawl fishery in Georgia. Between December 2005 and December 2012, observers accompanied commercial fishers utilizing trawl gear to target cannonball jellyfish in the coastal waters off Georgia; a total of 133 tows were sampled. Observed tow duration ranged from 0.15 to 1.22 h, averaging 0.55 h/tow. During the study period, 1,488 finfish and 150 invertebrates were collected, and 13 individuals representing four species of concern were present in the bycatch. The most numerous species were the Harvestfish Peprilus paru (n = 677), Co...

Studies of population genetic structure in relation to ecological and evolutionary processes are crucial for conservation genetics and particularly for sustainable management of fisheries. However, such knowledge is not always available for the management of fisheries, as is the case of the edible cannonball jellyfish Stomolophus spp. fishery in the Gulf of California, Mexico. The aim of this study is describe the population genetic structure of cannonball jellyfish in the Gulf of California. We used sequences of cytochrome oxidase I (COI) and microsatellite markers in five locations within the Gulf of California and the southern Pacific coast. Both COI and microsatellite markers corroborated the presence of two differentiated genetic lineages in the fishing areas, which diverged around 1.17 Mya: Stomolophus sp.1, distributed in the Golfo de Santa Clara; and Stomolophus sp.2, in the southern region of the Gulf of California and the Pacific coast of the Baja California peninsula. In addition, significant differentiation between the four locations within the lineage Stomolophus sp.2 was found (mean FST: 0.56 and 0.12 for COI and microsatellites respectively). Our results are consistent with the endemism and phylogeographic break hypotheses proposed for the northern region of the Gulf of California. We proposed that the historical geology and complex oceanography of the Gulf of California might be responsible of this species-level differentiation. Conversely, the population structure within Stomolophus sp.2 could be more related to the life cycle, and particularly due the short larval dispersal stage of cannonball jellyfish in the Gulf of California.

The article discusses the consumption of invasive species as a means of eradicating them. An overview of several invasive species the author has served at his restaurant, Miya's Sushi, is presented which includes a soup made from European green crabs, called La Soupe des Mean Greenies, a dish made from cannonball jellyfish and Australian rabbits, called Peanut Butter, and Jelly, and a dish made from feral hogs, called Oinkimo.

Jellyfish has been captured in Asia for 1700 years, and it has been considered a delicacy. Since the 70s important jellyfish fisheries have developed in several parts of the world, with catches increasing exponentially, reaching 500,000 tons per year in the mid-nineties. In Mexico, only the cannonball jellyfish Stomolophus meleagris is captured commercially. Most of the capture of this jellyfish species is obtained within the Gulf of California, specifically in the state of Sonora. The total reported capture in 2010 was 16,581 metric t and 14,220 in 2011. With these capture volumes jellyfish was ranked as the third most important fishing resource in the state of Sonora. The fishing season in Sonora is from April to May; a total of 4 or 5 weeks, and the catch per unit effort is around 3 tons by trip. Currently, there are nine jellyfish marketing companies, with about 20 processing plants distributed along the coast of Sonora, primarily in Guaymas, Kino Bay, and Puerto Penasco. Although the process is simple, the large amounts of jellyfish required and the need to optimize production costs make jellyfish processing an intense activity that employs hundreds of people during the fishing season, becoming an alternative employment for the people who depend on the fishing industry.

The Cannonball jellyfish (Stomolophus sp.) is a species of jellyfish with high relevance in artisanal fishing. Studies of their populations do not extend beyond the morphological descriptions knowing that presents a great morphological variability. However, there are no genetic studies to determine the number of independent populations, so microsatellite markers become a suitable option. Since there are no species-specific microsatellite loci, in this paper, 14 new microsatellite loci are characterized. Microsatellite loci were isolated de novo through next generation sequencing, by two runs on Illumina MiSeq. A total of 506,771,269 base pair were obtained, from which 142,616 were microsatellite loci, and 1546 of them could design primers. We tested 14 primer pairs on 32 individuals from Bahía de La Paz, Gulf of California. We observed low genetic variation among loci (mean number of alleles per locus = 4.33, mean observed heterozygosity 0.381, mean expected heterozygosity 0.501). These loci are the first ones described for the species and will be helpful to carry out genetic diversity and population genetics studies. Fil: Getino Mamet, Leandro Nicolás. Instituto Politécnico Nacional 195; México. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina Fil: Valdivia Carrillo, Tania. Instituto Politécnico Nacional 195; México Fil: Gómez Daglio, Liza. University of California; Estados Unidos Fil: García De León, Francisco Javier. Instituto Politécnico Nacional 195; México

Three species of Carangidae family were caught incidentally during collection of cannonball jellyfish (Stomolophus meleagris) in Bahía de La Paz, Gulf of California, Mexico. All fish were measured, preserved and identified as post flexion larvae and early juvenile of Chloroscombrus orqueta, Hemicaranx leucurus and Caranx caballus. C. orqueta stood out in frequency and abundance. H. leucurus were found only in autumn, while the others were present in different seasons. This is the first time recording H. leucurus and C. caballus associating with cannonball jellyfish. Further studies must evaluate this association as all fish caught were at vulnerable stages, and must be considered in jellyfish fishery management.

This contribution discloses the actual distribution of cannonball jellyfish ( Stomolophus meleagris ) in Co lombia, the scarcity of studies in the Colombian Caribbean and is evident nulls made to the Colombian Pacific. The presence of S. meleagris near Bahia Malaga, where three juveniles were collected jellyfish is recorded for the first time for the Colombian Pacific; described briefly found specimens, which were measured and photographed. Currently, jellyfish are deposited in the Marine Museum of Natural History of Colombia, in the city of Santa Marta.

The cannonball jellyfish Stomolophus meleagris is regarded as a fishery resource with high commercial value, but with scarce biological information. With the aim to generate preliminary information on reproductive aspects, the present study analyzes its fecundity, based on the estimated number of vitellogenic oocytes in the gonad; in addition, we evaluated its relationship with the jellyfish body length, diameter and wet weight; and we established the relationship of the gonadosomatic index (IGS) with the jellyfish diameter and length. For this, a total of 30 specimens were collected, measured and weighed in a monthly basis, in Las Guasimas lagoon from January to May 2006. In order to estimate the gonad volume, 60 mature females were analyzed and their gonads were extracted and stained with hematoxylin-eosin. Gonad images from histological preparations were analyzed and the number of vitellogenic and previtellogenic oocytes obtained. We used catch data from The Guasimas for population recruitment analysis, that was estimated with FISAT II. Among results, we found that fecundity increased with jellyfish length, diameter and total wet weight. The lower fecundity rates occured on February and the highest during May (11 873 071 and 37 528 197 millions of vitellogenic oocytes per gonad, respectively). The IGS increased with length and diameter of the specimens, at its maximum value of 3.7% was observed in May. A continuous production of previtellogenic oocytes were observed during the full collection period. The maximum recruitment was observed in July and November (37.50% and 28.01% respectively). The high fecundity observed in S meleagris, suggests a high population reproductive potential that may support the possibility of an important fishery consolidation on this jellyfish.

Cannonball jellyfish (Stomolophus meleagris) from the Gulf of Mexico has been under investigation as a potential source to meet the market demand for jellyfish food in Asia. Traditionally, jellyfish are processed by curing fresh jellyfish with salt and alum, and then the cured jellyfish are desalted in water before consumption. Very little is known about the inorganic constituents of jellyfish. In this study fresh and desalted processed cannonball jellyfish were examined for 22 elements using inductively coupled plasma optical emission spectrometry. The desalted processed tissues had significantly higher Al concentrations (leg, 688 μg/g; umbrella, 271 μg/g) than fresh jellyfish (leg, 0.29 μg/g; umbrella,1.63 μg/g). Concentrations of macro elements, such as Ca, Mg, K, and Na, were high in fresh jellyfish and rather low in desalted processed tissue. The results should be useful in providing biological and nutritional information about fresh and processed jellyfish. Keywords: Jellyfish; ICP; mineral elements

Jellyfish have been exploited commercially by Chinese as an important food for more than a thousand years. Semidried jellyfish represent a multi-million dollar seafood business in Asia. Traditional processing methods involve a multi-phase processing procedure using a mixture of salt (NaC1) and alum (A1K[SO4]2 · 12 H2O) to reduce the water content, decrease the pH, and firm the texture. Processed jellyfish have a special crunchy and crispy texture. They are then desalted in water before preparing for consumption. Interest in utilizing Stomolophus meleagris L. Agassiz, cannonball jellyfish, from the U. S. as food has increased recently because of high consumer demand in Asia. Desalted ready-to-use (RTU) cannonball jellyfish consists of approximately 95% water and 4–5% protein, which provides a very low caloric value. Cannonball jellyfish collagen has shown a suppressing effect on antigeninduced arthritis in laboratory rats. With the great abundance of cannonball jellyfish in the U. S. coastal waters, turning this jellyfish into value-added products could have tremendous environmental and economicbenefits.

A few large jellyfish species in the order Rhizostomeae constitute an important food in Chinese cooking. For more than 1700 years, they have been exploited along the coasts of China. Such jellyfish became an important fishery commodity of Southeast Asian countries in the 1970s with increasing demand from the Japanese market. Recently, Japan has imported 5400–10000 tons of jellyfish products per year, valued at about 25.5 million US dollars, annually from the Philippines, Vietnam, Thailand, Malaysia, Indonesia, Singapore and Myanmar. Judging from the type names at market and the external appearance of the semi-dried products, the edible jellyfish harvest in Southeast Asia is composed of more than 8 species. They are caught by various kinds of fishing gear including setnets, drift-nets, hand-nets, scoop-nets, beach-seines and hooks. The fishery is characterized by large fluctuations of the annual catch and a short fishing season that is restricted from two to four months. The average annual catch of jellyfish between 1988 and 1999 in Southeast Asia is estimated to be about 169000 metric tons in wet weight and the worldwide catch is approximately 321 000 metric tons. Needs for future study on the biology of rhizostome jellyfish are discussed as they relate to understanding population fluctuations.

Stages in the life history of the scyphozoan Stomolophus meleagris from the planula to the newly liberated ephyra were raised in the laboratory and are described for the first time. After swimming actively for 2—5 days, the ciliated planula larvae settled and scyphistoma morphogenesis occurred. Fully developed scyphistomae were cone-shaped and bore a whorl of about 16 tentacles around a dome- or knob shaped proboscis. Podocyst formation was the only observed method of asexual reproduction in cultures of scyphistomae maintained for one month. Strobilation began as soon as nine days after scyphistoma morphogenesis and occurred in scy phistomae with as few as eight tentacles. The strobilation process, completed in about 3.5 days at 25°C,was not accompanied by any noteworthy color changes. Most strobilae produced two ephyrae each, although the number varied from one to three. Some scyphistomae began to strobilate a second time within a week after completion of an initial round of strobilation. Newly liberated ephyrae possessed a normal complement of eight lappet pairs and eight rhopalia. They were mor phologically similar to, yet distinguishable from, ephyrae of the related species Rhopilema verrilli. None of the examined stages of S. meleagris contained algal symbionts.

A pilot plant process was developed to produce salted dried jellyfish product from cannonball jellyfish (Stomolophus meleagris). Processed products containing an average of 68% moisture, 5.5% protein, 26% ash and 25% salt were obtained by brining with different mixtures of salt (7.5–25%) and alum (1–2.5%) over 1 wk. Mechanical drying was also tested by using a heat pump system dryer. Chemical and physical analyses and sensory properties of cannonball jellyfish products compared favorably with market products. Levels of calcium, magnesium and iron in the jellyfish were higher than those of zinc and copper.