The Function of a Heteromorph Antennule in a Spiny Lobster, Panulirus Argus

1965 ◽  
Vol 43 (1) ◽  
pp. 55-78
Author(s):  
D. M. MAYNARD ◽  
M. J. COHEN

1. The effects of electrical and mechanical stimulation upon a ‘naturally occurring’ heteromorph appendage growing in place of one eyestalk in Panulirus argus were examined. The heteromorph resembled the outer flagellum of the antennule in form. 2. Heteromorph stimulation elicited both a generalized withdrawal response, and a specific depression of the third segment and flagellum of the ipsilateral antennule. Such a depression response was also elicited upon stimulation of the ipsilateral outer flagellum of the normal antennule and by no other input investigated. 3. The basic similarity of the two responses was confirmed by electromyography and by intracellular recordings from motor neurons and interneurons within the lobster brain. 4. It was concluded that at least one afferent fibre component from the heteromorph and normal flagellum terminated upon the same interneuron pools, while avoiding others, and that consequently these observations provide evidence for the formation of functional inter-neuronal connexions according to type specificity.

Crustaceana ◽  
1996 ◽  
Vol 69 (8) ◽  
pp. 958-973 ◽  
Author(s):  
Enrique Lozano-Alvarez

AbstractThe spiny lobster catch from Bahia de la Ascensión, a large bay on the central coast of the Mexican Caribbean, is composed mainly of young adults and large juveniles of Panulirus argus. The fishery in this bay is based on artificial shelters called "casitas". A substantial part of the lobsters found beneath the casitas is of sublegal size (minimum size limit ~ 74 mm carapace length, CL). The possibility of ongrowing sublegal juveniles in portable sea enclosures to maximize the harvestable biomass was explored. The enclosures (3 x 3 x 1 m) were installed in shallow depths in the bay. Juveniles taken from nearby casitas were introduced in the enclosures and kept for different periods. Lobsters were fed with live molluscs and fish remains and were provided with suitable shelters. Experiments were conducted in two stages, in 1992 and 1993. Growth in size (CL) and in harvestable biomass (weight of legal-size lobsters) was examined. Maximum growth rates, lower percentages of mortality, and higher increases in harvestable biomass of lobsters were obtained after about 45 days. Confinement periods longer than 45 days resulted in reduced growth and higher mortality. Observations on lobster behaviour showed an increase in aggressive encounters and dominance displays from the third week of captivity onwards, which could be the main cause for the increase in mortality. The alternative of ongrowing sublegal juveniles for short periods (45 days), in conjuction with the casita system, could help increase the unit value of the catch.


The stomatogastric nervous system of the reptantian Decapoda Crustacea, particularly the small isolated stomatogastric ganglion containing the 25-30 motor neurons that control the muscles of the gastric mill and the pyloric filter of the stomach, is an important preparation for research in comparative neurophysiology. Unfortunately there are no comprehensive descriptions of the neuromuscular system of the stomach in these animals. Therefore, since the stomatogastric motor neurons are identified by reference to the muscles they innervate, it has been difficult to identify neurons within or between species. The most important features for classifying the muscles of the decapod stomach are the ossicles to which the muscles attach. In the latter part of the last century Mocquard demonstrated that the stomach ossicles of the decapods could be compared in different groups despite the large variations from group to group. A summary of Mocquard’s (1883) classification scheme, with some modifications, is given. The scheme recognizes 33 ossicles in seven categories (cardiac gastric mill, I—VII; lateral supporting cardiac ossicles, VIII-XV ; ossicles of the cardio-pyloric valve, XVI-XVIII; supporting ossicles of the dorsal pyloric stomach, XIX -XXI; supporting ossicles of the ventral pylorus and ampullae, XXII-XXVII; supra-ampullary ossicles, XXVIII-XXX ; supporting ossicles of the lateral pylorus, XXXI-XXXIII). Where necessary, comments are then made on the ossicles of the three divergent species studied, the blue crab, Callinectes sapidus (Brachyura); the lobster, Homarus americanus (Macrura) and the spiny lobster Panulirus argus (Palinura). Most of the thirty-three ossicles are found in each of the species, but there are some major differences between species. Callinectes , for example, has the most complex ossicle system and Panulirus the most reduced.


1984 ◽  
Vol 52 (1) ◽  
pp. 54-73 ◽  
Author(s):  
D. F. Russell ◽  
D. K. Hartline

The properties of neurons in the stomatogastric ganglion (STG) participating in the pattern generator for the gastric mill rhythm were studied by intracellular current injection under several conditions: during ongoing gastric rhythms, in the nonrhythmic isolated STG, after stimulation of the nerve carrying central nervous system (CNS) inputs to the STG, or under Ba2+ or Sr2+. Slow regenerative depolarizations during ongoing rhythms were demonstrated in the anterior median, cardiopyloric, lateral cardiac, gastropyloric, and continuous inhibitor (AM, CP, LC, GP, and CI) neurons according to criteria such as voltage dependency, burst triggering, and termination by brief current pulses, etc. Experiments showed that regenerative-like behavior was not due to synaptic network interactions. The slow regenerative responses were abolished by isolating the stomatogastric ganglion but could be reestablished by stimulating the input nerve. This indicates that certain CNS inputs synaptically induce the regenerative property in specific gastric neurons. Slow regenerative depolarizations were not demonstrable in gastric mill (GM) motor neurons. Their burst oscillations and firing rate were instead proportional to injected current. CNS inputs evoked a prolonged depolarization in GM motor neurons, apparently by a nonregenerative mechanism. All the gastric cells showed prolonged regenerative potentials under 0.5-1.5 mM Ba2+. We conclude that the gastric neurons of the STG can be divided into three types according to their properties: those with a regenerative capability, a repetitively firing type, and a nonregenerative "proportional" type. The cells are strongly influenced by several types of CNS inputs, including "gastric command fibers."


2018 ◽  
Vol 76 (2) ◽  
pp. 442-451 ◽  
Author(s):  
Gaya Gnanalingam ◽  
Mark J Butler ◽  
Thomas R Matthews ◽  
Emily Hutchinson ◽  
Raouf Kilada

Abstract In crustaceans, ecdysis was long believed to result in the loss and replacement of all calcified structures, precluding the use of conventional ageing methods. However, the discovery of bands in the gastric ossicles of several crustaceans with some correlation with age suggests that direct age estimation may be possible. We applied this method to a tropical spiny lobster, Panulirus argus, one of the most iconic and economically valuable species in the Caribbean. The presence of growth bands was investigated using wild lobsters of unknown age and was validated with captive reared lobsters of known age (1.5–10 years) from the Florida Keys, Florida (USA). Bands were consistently identified in ptero- and zygo-cardiac ossicles of the gastric mill and did not appear to be associated with moulting. Validation with known age animals confirms that bands form annually. Counts between independent readers were reproducible with coefficients of variation ranging from 11% to 26% depending on reader experience and the structure used. This study demonstrates, for the first time, that direct age determination of P. argus is possible.


Crustaceana ◽  
2013 ◽  
Vol 86 (2) ◽  
pp. 158-181 ◽  
Author(s):  
Raúl Cruz ◽  
Carlos A. Borda

Estimates of spiny lobster stocks (Panulirus argus Latreille, 1804) represent a fundamental input for population assessment models and are, therefore, indispensable for proper management. In this study we analysed methodologies employed in the Gulf of Batabanó (Cuba) and Providencia and Santa Catalina (Colombian Caribbean) to estimate abundance (N) and stock productivity. We found evidence that the relative abundance (CPUE) for trap-like jaulones and skin diving in natural shelters was likely to remain high despite the decline in abundance (hyperstability). In contrast, the proportionality between CPUE and N was satisfactory in artificial shelters (Cuban pesqueros). Stock productivity was greater for jaulones (22 288 kg/km2) than for pesqueros (1309 kg/km2) or natural shelters (15.25 kg/km2), reflecting differences in the productive capacity of each type of fishing gear. In natural shelters the exploitable biomass is under great fishing pressure and the reproductive stock is likely to decrease. Thus, the West zone of Providencia and Santa Catalina, characterized by high-density seagrass and mangrove, should be designated a marine protection area to prevent a lobster fishing collapse. The most effective measure to revert the lobster fishing collapse in Cuba would be to ban the use of jaulones and liftable pesqueros, thereby reducing fishing intensity.


Aquaculture ◽  
2010 ◽  
Vol 310 (1-2) ◽  
pp. 178-185 ◽  
Author(s):  
Erick Perera ◽  
F.J. Moyano ◽  
L. Rodriguez-Viera ◽  
A. Cervantes ◽  
G. Martínez-Rodríguez ◽  
...  

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