Harriet M. Perry

Biochemical composition of the deep-sea red crab Chaceon quinquedens (Geryonidae): Organic reserves of developing embryos and adults

Deep-sea red crabs Chaceon quinquedens (Smith) were collected in traps at depths of 860 and 1043 m in the northern Gulf of Mexico. Ovigerous crabs were maintained in the laboratory and the developing embryos were sampled every 2 wk until hatching. Proximate analysis (lipid, protein, carbohydrate, and ash) of embryos was performed to determine patterns and rates of organic reserve utilization during embryogenesis. Midgut gland, gonads, and clutch (as appropriate) of adult crabs (males, non-ovigerous females and ovigerous females) were analyzed for the same components as the embryos. Red crab embryos exhibited different patterns of yolk deposition and subsequent depletion of yolk components during embryogenesis. There was a range of lipid to protein (L:P) ratios among the different clutches examined, indicating plasticity in the relative proportions of lipid and protein yolk. The energy used for embryogenesis was estimated by converting the amounts of lipid, protein and carbohydrate in the embryos to their caloric equivalents; final values, taken from 9 mo-old embryos whose siblings were hatching as zoeae, were subtracted from the initial values of sibling embryos sampled at the time of collection (2 to 3 mo old). The amount of energy consumed during embryogenesis in the laboratory was relatively constant (0.12 to 0.13 cal egg-1). There was considerable variability among the concentrations of organic reserves in the midgut gland of adult crabs and in the ovaries of females. Variations in midgut gland L:P ratios and ovaries were related to the reproductive status of the females, but there were no trends related to depth of capture.

Factors Influencing Refuge Occupation by Stone Crab Menippe adina Juveniles in Mississippi Sound

Abstract A greater understanding of population dynamics is essential in the management of any species. The Western Gulf stone crab, Menippe adina, is taken as incidental by-catch in the blue crab, Callinectes sapidus, fishery in Mississippi. However, there is a lack of information on the ecology of M. adina in estuaries of the northern Gulf of Mexico. We know that M. adina is associated with hard-bottom habitats such as rock-rubble jetties and oyster reefs and that this habitat is sparse in Mississippi Sound, which mainly consists of soft-bottom habitat. Many studies have demonstrated that habitat complexity is important to several benthic crustaceans because it provides a matrix of different sized refuges that organisms can use to escape from predation. The importance and availability of refugia varies throughout the life history of organisms because of the increase in size of an organism as it grows. Refuge limitation acting on a specific size class may create a demographic bottleneck thereby limiting the production of a population through mortality, migration, or stunting of the affected size class. We tested this refuge limitation bottleneck hypothesis in juvenile stone crabs by supplementing an existing oyster reef with four different sizes of polyvinyl chloride (PVC) pipe. We found that lack of refuge affected both population size structure and density of large juvenile stone crabs on the reef. We also found that competition for available refuges may occur among M. adina and two other xanthid crab species, Eurypanopeus depressus and Panopeus simpsoni. We examined the diet of oyster toadfish, Opsanus beta, in Mississippi Sound and found that the three xanthid crabs comprised a significantly large portion of oyster toadfish diet. Predation by O. beta emphasized the importance of the availability of suitable refugia for the xanthids.

Developing jellyfish strategy hypotheses using circulation models

Little information exists relating life histories of jellyfish species to ocean currents. Successful cycling from sessile polyp to mature jellyfish and back must doubtlessly rely on circulation patterns that serve to retain the species in an optimum environment or disperse the species for other adaptive advantages. In this study, current vectors from a high resolution numerical model of the Gulf of Mexico are applied to a simple advection scheme to develop estimates of time and distance scales from probable polyp habitats to areas in which mature scyphomedusae are observed in the northern Gulf of Mexico. Although seasonal patterns of wind stress form the basis for circulation processes that favour shoreward distribution of medusae of oceanic origin, this dynamic may be altered by deep basin events that occur during critical life history stages. Inter-annual differences in distributional patterns of the sea nettle, Chrysaora quinquecirrha (Desor 1848), in Mississippi coastal waters could be explained by Loop Current processes that alter shelf circulation in the Mississippi Bight.

Respiratory and cardiovascular responses of two species of deep-sea crabs, Chaceon fenneri and C. quinquedens, in normoxia and hypoxia

The respiratory and cardiovascular variables in Chaceon fenneri and C. quinquedens were examined in animals during normoxia, animals exposed to hypoxia, and animals allowed to recover in normoxia. Chaceonfenneri was characterized by a relatively low metabolic rate (low oxygen uptake), and low ventilatory frequency. This species displayed a pattern of oxy-independent 02 uptake when exposed to hypoxia: MO2 was maintained primarily through hyperventilation. At an environmental PO2 of about 25 torr, respiratory and cardiovascular functions shut down, and the animal appeared to make the transition to exclusively anaerobic energy production. Lactate accumulated in the hemolymph during hypoxia and during recovery. Recovery was also characterized by elevated 02 uptake, and prolonged hyperventilation, indicating the repayment of an oxygen debt. Oxygen uptake in resting C. quinquedens was roughly double that in C. fenneri, and ventilatory frequency was 3-fold higher. MO2 declined in hypoxia, and hyperventilation was absent, a more typical oxy-dependent pattern of respiration. The ambient PO2 at which ventilatory and cardiovascular shutdown occurred was about 17 torr, but oxygen uptake continued at very low levels even in severe hypoxia. Lactate buildup in the hemolymph was not observed. During recovery, normal levels of 02 uptake were quickly restored, and hyperventilation was absent. Chaceon quinquedens appeared not to utilize anaerobic metabolism during hypoxia or to incur an oxygen debt. The differences in respiratory and cardiovascular responses to hypoxia in these two species appear to be due to a combination of differences in metabolic rate and body morphology. The basic mechanisms of crustacean respiration, ventilation, and cardiovascular function have been the subjects of extensive investigation for more than a decade, especially among the decapods (for review, see Taylor, 1982; Cameron and Mangum, 1983; McMahon and Wilkens, 1983; McMahon, 1988). The picture that has emerged is one of a common mechanism that displays a graded pattern of responses to varying environmental conditions. One of the most commonly studied environmental variables has been low oxygen tensions. In response to declining oxygen tensions, decapods show one of two general patterns: (1) animals exhibiting oxy-independent respiration, maintaining normal rates of oxygen uptake (MO2), or (2) animals exhibiting oxy-dependent respiration, in which MO2 declines with ambient oxygen tension (Mangum and Van Winkle, 1973). These two patterns have also been termed oxyregulation and oxyconformity, respectively (Taylor, 1982). Most decapods display some degree of oxy-independent respiration with MO2 being maintained by a combination of hyperventilation and increased stroke volume of the heart. This preserves both the PO2 gradient across the gills and hemolymph PO2 until ambient oxygen tensions reach a critical low value (Mangum and Van Winkle, 1973; Taylor, 1976, 1982; McMahon and Wilkens, 1983; McMahon, 1988). Below that critical value (termed Pc) ventilatory and cardiovascular compensation no longer provide the necessary oxygen for aerobic respiration; hemolymph PO2 declines as the animal uses up its venous 02 reserve, and ultimately ventilation and cardiac function are shut down as the animal makes the transition to anaerobic energy production. Patterns of oxy-independent and oxy-dependent respiration, ventilatory and cardiovascular responses, and values for Pc have been described for species of decapod crustaceans from a wide variety of habitats and which display different life-styles. Studies

Red Snapper Larval Transport in the Northern Gulf of Mexico

Abstract This study examines the advection of red snapper Lutjanus campechanus larvae in the northern Gulf of Mexico. The potential for repopulating the eastern Gulf stock through larval transport from the more populous western stock is addressed. Transport pathways across topographic features that inhibit alongshelf flow (e.g., the Mississippi River delta, DeSoto Canyon, and the Apalachicola peninsula) and interregional larval transport are considered. An advective field of currents is developed from a large database of drifter and moored currents, augmented by an operational model to fill gaps. The starting points for larval transport are the locations and day of the year of larval captures from the Southeast Area Monitoring and Assessment Program ichthyoplankton surveys. Because the field of currents is derived from near-surface observations and the depth distribution of larvae is uncertain, findings are expressed in terms of maximal transport pathways. Transport pathways were principally vectored towa...

Calcium concentration in seawater and exoskeletal calcification in the blue crab, Callinectes sapidus

Abstract The blue crab, Callinectes sapidus Rathbun, supports valuable commercial fisheries in the temperate areas of the coastal Atlantic states and US Gulf of Mexico (GOM). Soft crabs form a small part of the total United States blue crab landings, but have a higher market value on a per pound basis than do hard crabs. The soft crab industry depends upon the capture of premolt crabs which are held in open or closed seawater systems until they molt. A major factor limiting profitability is the labor-intensive nature of the shedding operation. Extending the length of time crabs remain in the softshell stage would significantly reduce labor requirements. Exoskeletal calcification in blue crabs is achieved predominantly with calcium absorbed from seawater. In the present study, seawater at a salinity of 12‰, with calcium levels reduced to 60–80% of normal, decreased the calcification rate without increasing shedding mortality. Salinity did not influence calcification rates for crabs shed at 5‰, 12‰, and 25‰, provided calcium concentrations were within the normal ranges for their respective salinities: x =54, 139, and 281 mg/l. Crabs molting over the range of test salinities in waters with normal calcium levels remained soft for ∼4 h. At test salinities with reduced calcium levels, the rate of exoskeletal calcification decreased as total ionic strength of the seawater increased. Crabs shed in low-calcium seawater at 25‰ remained longer in the softshell stage than crabs shed at 5‰ or 12‰. Modifying existing closed system shedding facilities to incorporate low-calcium seawater technology would reduce labor requirements, increase profitability, and produce a higher quality soft crab.

Fecundity and Egg Diameter of Primiparous and Multiparous Blue Crab Callinectes Sapidus (Brachyura: Portunidae) in Mississippi Waters

ABSTRACT Blue crabs Callinectes sapidus Rathbun, 1896 support large commercial and recreational fisheries along the Atlantic coast and in the Gulf of Mexico (GOM). Female blue crabs are traditionally believed to produce one to six broods in their lifetime. However, recent evidence has shown that females have the ability to spawn up to eight broods in a single spawning season, with as many as 18 broods over their lifespan. In this study, fecundity and egg diameter were examined by brood class (primiparous, multiparous) in the spring and summer/fall. Mean carapace width of females was significantly different between brood class and season, with the largest females in the spring. There was a positive relationship between fecundity and carapace width. Although primiparous spring females were the most fecund (3.2 ± 1.5 million eggs), no statistically significant differences in fecundity by brood class and season were found. Loss of eggs occurred during embryonic development; primiparous females lost ∼0.9 million eggs whereas multiparous females lost ∼0.1 million. Egg diameter and carapace width of the female were positively correlated. There was no difference in egg diameter between brood classes, but eggs were 9.9% larger in diameter during the spring than summer/fall. There was an inverse relationship between fecundity and egg diameter. Seasonality appeared to play an important role in the reproductive life history of blue crabs in the northern GOM. Larger crabs and larger eggs in the spring may be related to quality and quantity of available food and temperature conditions for optimal growth.

A New Microphallid Trematode from the Blue Crab in the Northern Gulf of Mexico

Levinseniella (Monarrhenos) capitanea n. sp. is described from metacercariae on the hepatopancreas and gonads of Callinectes sapidus Rathbun from Louisiana and Mississippi. It can be distinguished from all other members of the genus by possessing 11–21 atrial pockets and an acetabulum larger than the oral sucker, not possessing a pharynx nor well-developed ceca, and being 1.9–3.6 mm in length. Heardlevinseniella Yamaguti, 1971 is considered a synonym of Levinseniella Stiles & Hassal, 1901. An easily visible microphallid metacercaria was found on the hepatopancreas and gonads of a few large specimens of the blue crab from the northern Gulf of Mexico. Over 1500 various-sized individuals of Callinectes sapidus Rathbun and over 500 of C. similis Williams from Mississippi Sound and adjacent waters taken between June 1970 and September 1971 were routinely inspected for obvious parasites. Of these crabs, only four from a sample of 41 C. sapidus in July and August 1971 from the vicinity of Raccoon Island, Louisiana, and one from 92 C. sapidus in August 1971 from Cat Island, Mississippi, had the metacercaria present. The mean width of the carapace of the infected crabs was 151 mm. Of the five, three were females in a stage between first and second ovulations and two were mature males. The species is described below even though it is a larval stage because its reproductive system is well developed and its characteristics are unusual. O V E R S T R E E T A N D PE R R Y , T R A N S A C T I O N S O F T H E A M . M I C R O S C O P I C A L S O C I E T Y 9 1 (1 9 7 2 ) 2 Materials and Methods The trematodes were fixed in hot AFA under slight pressure and stained with Van Cleave’s hematoxylin or studied alive with and without neutral red stain. All figures except Figure 2 were drawn with the aid of a camera lucida, and measurements are given in micra. Figures 1–5. Levinseniella capitanea (scale values are micra). Fig. 1. Holotype, ventral view. Fig. 2. Atrial pocket, illustrated from photograph of living specimen. Fig. 3. Terminal genitalia and associated structures of a paratype, ventral view. Fig. 4. Male papilla of different paratype illustrating variation in both the organ and the tip, ventral view. Fig. 5. Anterior end of holotype illustrating sensory papillae, ventral view. O V E R S T R E E T A N D PE R R Y , T R A N S A C T I O N S O F T H E A M . M I C R O S C O P I C A L S O C I E T Y 9 1 (1 9 7 2 )

Fishery-Related Morphometric Characteristics of Menippe adina from the North-Central Gulf of Mexico

Abstract Fishery-related morphometric characteristics of the recently described gulf stone crab Menippe adina were measured, providing data applicable to managing the species. Because data used in managing crab stocks have traditionally been based on carapace width, we examined the relationship between propodus length (PL) and carapace width and compared it to similar data for the heavily exploited Florida stone crab M. mercenaria. Claws for M. adina reach harvestable size (70 mm PL, minimum legal size in Florida) when carapace widths are 82 mm for males and 92 mm for females. Menippe adina exhibits allometric growth, and the transition point (carapace width) at which differential growth occurs appears to be related to sexual maturity. Males and females exhibit similar relationships of propodus length to carapace width below the transition point. Above the transition point, males display a greater increase in propodus length per incremental increase in carapace width and enter the fishery at a smaller siz...

Heavy metals in red crabs, Chaceon quinquedens, from the Gulf of Mexico

The red crab, Chaceon quinquedens, is distributed in deep waters of the Gulf of Mexico (GOM) and is most abundant in an area associated with sediment deposition from the Mississippi River. Sediment geochemistry and biological and ecological traits of red crabs favor accumulation of contaminants. Red crabs, sediment, and bottom water samples were taken from three distinct geographic locations representing areas with differing exposure to contaminant laden effluents from the Mississippi River. Inductively coupled plasma spectrophotometry and atomic absorption spectrophotometry were employed to determine levels of heavy metals in red crab muscle tissue. Ion site partitioning was used to determine metal speciation in sediments. Red crabs showed evidence of heavy metal bioaccumulation in all sample areas with high variability in contaminant levels in individual crabs for some metals. Bioavailability of metals in sediment did not always result in accumulation in muscle tissue.