Photosynthesis from stolen chloroplasts can support sea slug reproductive fitness

Some sea slugs are able to steal functional chloroplasts (kleptoplasts) from their algal food sources, but the role and relevance of photosynthesis to the animal host remain controversial. While some researchers claim that kleptoplasts are slowly digestible ‘snacks’, others advocate that they enhance the overall fitness of sea slugs much more profoundly. Our analysis shows light-dependent incorporation of 13 C and 15 N in the albumen gland and gonadal follicles of the sea slug Elysia timida , representing translocation of photosynthates to kleptoplast-free reproductive organs. Long-chain polyunsaturated fatty acids with reported roles in reproduction were produced in the sea slug cells using labelled precursors translocated from the kleptoplasts. Finally, we report reduced fecundity of E. timida by limiting kleptoplast photosynthesis. The present study indicates that photosynthesis enhances the reproductive fitness of kleptoplast-bearing sea slugs, confirming the biological relevance of this remarkable association between a metazoan and an algal-derived organelle.

Differences in the spermatozoa and ova of two species of giant African land snails (Archachatina marginata and Achatina achatina)

A comparative study of the gametes of two species of Giant African Land Snails; Archachatinu marginata and Achatina achatina was carried out. Three groups of snails weighing 80-100,101-150 and 151-250 g were used in a 3x2 factorial design, with 5 replicates, involving a total of 30 snails. Albumen gland, little hermaphrodite duct, spermotheca and ovo-testis were examined for the presence of ova and spermatozoa. The morphology of the spermatozoa and ova of both species Was studied. Ova were found in the albumen gland and ovo-testis. Spermatozou were only found in the little hermaphrodite duct. Spermatozoa head and tail lengths were not significantly (P>0.05) different between species, while the mid-piece length was significantly (P<0.05) different. Liveweight group 101-150 g had the highest number of spermatozoa and ova count in both species. Morphologically, spermatozoa head, collar and mid-piece crest differed between species Archachatina marginata spermatozoa had pointed head, longer collar and highest number of mid-piece crests compared to Achatina achatina. Ova seen in the ovo-testis of A. marginata were larger compared to those seen in A. achatina. It was concluded from the study that there are differences in the morphology and dimensions of their germ cells.

Nutritional analysis of the albumen gland of giant African land snail (Archachatina marginata) from six Southwest states, Nigeria

The albumen gland is a vital part of visceral mass of giant African land snail (GALS) and its very rich in nutrients. As with other parts of snails, its composition is influenced by diet, location, age and species. The chemical compositions of albumen gland of GALS across the south western states of Nigeria have not been evaluated despite their diverse climatic conditions. Three hundred and sixty (360) Archachatina marginata were obtained from six south west states (60 snails/ state) and the albumen gland samples were analyzed for their proximate composition (crude protein, fat, ash, fibre and carbohydrate), minerals content (K+, Ca2+, P, Na+, Mg2+, Cl-, Fe2+), anti-nutrients and vitamins composition. The crude protein of the gland ranged between 12.93% and 24.40% with Ekiti state recording the highest value and Osun the least. The fat content was low (1.14%-2.29%) and no fibre was detected in the albumen gland. Snails from Ekiti and Ondo states had significantly higher Ca2+, P and Mg2+ than other states. No Vitamin C was detected in the gland across the states while Vitamin A values ranged from 38.68 (Lagos) to 45.51 (Ondo). Least anti-nutrient concentrations were recorded by snails from Ondo and Ekiti states, while Lagos state recorded the highest (except flavonoid and oxalate). Albumen glands of snails from Ekiti and Ondo states are thus more nutritious than that from other states and can be safely consumed by both man and farm animals. La glande albumen est une partie vitale de la masse viscérale de l'escargot terrestre géant africain (le 'GALS') et elle est très riche en nutriments. Comme pour d'autres parties d'escargots, sa composition est influencée par le régime alimentaire, l'emplacement, l'âge et l'espèce. Les compositions chimiques de la glande albumine de 'GALS' dans les États du sudouest du Nigéria n'ont pas été évaluées malgré leurs conditions climatiques diverses. Trois cent soixante (360) Archachatinamarginata ont été obtenus de six états du sud-ouest (60 escargots / état) et les échantillons de glande albumen ont été analysés pour leur composition immédiate (protéines brutes, graisses, cendres, fibres et glucides), teneur en minéraux (K+, Ca2+, P, Na+, Mg2+, Cl-, Fe2+), composition anti-nutriments et vitamines. La protéine brute de la glande variait entre 12,93% et 24,40%, l'état d'Ekiti enregistrant la valeur la plus élevée et Osun le moins. La teneur en matières grasses était faible (1,14% -2,29%) et aucune fibre n'a été détectée dans l'albumen. Les escargots des états d'Ekiti et d'Ondo avaient des Ca2+, P et Mg2+ significativement plus élevés que les autres états. Aucune vitamine C n'a été détectée dans la glande à travers les États alors que les valeurs de vitamine A variaient de 38,68 (Lagos) à 45,51 (Ondo). Les plus faibles concentrations d'anti-nutriments ont été enregistrées par les escargots des états d'Ondo et d'Ekiti, tandis que l'état de Lagos a enregistré les plus élevées (sauf les flavonoïdes et l'oxalate). Les glandes d'albumen des escargots des états d'Ekiti et d'Ondo sont donc plus nutritives que celles des autres états et peuvent être consommées en toute sécurité par l'homme et les animaux de ferme.

EFFECTS OF AESTIVATION DURATION ON TESTOSTERONE, HAEMOLYMPH BIOCHEMICAL PARAMETERS AND REPRODUCTIVE TRACT DIMENSIONS AND WEIGHT OF GIANT AFRICAN LAND SNAIL (Archachatina marginata) DURING DRY SEASON

Aestivation is a process of metabolic inactivity under which energy reserve are manipulated for survival. Reproductive apparatus and haemolymph biochemical agents also undergo phase manipulation as the duration continues. To determine the physiological influence on key hormone of reproduction and reproductive apparatus, seventy five A. marginata snails were used for this study. The snails were divided into five treatments with fifteen replicate each. Treatment include: Zero (0) week, Three (3) weeks, Six (6) weeks, nine (9) weeks and six (6) weeks post-aestivation. Parameters measured were: Testosterone concentration, haemolymph biochemical parameters (Total protein, albumin, globulin, Aspartate transaminase (AST) and Alanine transaminase (ALT), dimensions (length) and weight of the organs and tissues of the reproductive tracts (Ovo-testis, penis, vaginal, oviduct, little hermaphrodite duct, common hermaphrodite duct, vas deferens and albumen gland) gonado-somatic index and percentage mortality. Result showed that level of testosterone at three and six weeks of aestivation significantly reduced compared to the control. Also, at nine weeks of aestivation, the reduction was significantly greater than what was recorded at both three and six weeks of aestivation. But the testosterone levels were reversed at nine weeks post aestivation. Total protein and globulin were significantly influenced with both reaching a peak value at 9 weeks of aestivation while ALT, AST and albumin were not significantly affected. So also, of all the reproductive tract parts measured, organ weight, ovo-testis weight, penis weight and length were significantly influenced (P<0.001; P<0.001; P<0.05; P<0.001). Similarly, vaginal weight, oviduct weight, little hermaphrodite duct weight and length were also significantly affected together with vas deferens length and albumen gland length while aestivation duration had no significant influence on reproductive tract weight, ovo-testis length, vaginal length, oviduct length, little hermaphrodite duct length, vas deferens weight and albumen gland weight. Similarly, gonado-somatic index was also not significantly affected by aestivation duration. It was also obvious from this study that the highest mortality was recorded at 6 weeks of aestivation, followed by 9 weeks of aestivation while 3weeks and 6 weeks post-aestivation had the least mortality with the control intact. In conclusion, it is clear from this study that aestivation duration significantly influenced testosterone concentration, haemolymph biochemical parameters and some selected reproductive apparatus of A. marginata.

Taxonomic note on Trichelix horrida (Pfeiffer, 1863) from Laos, with a type catalogue of Moellendorffia, Trichelix, and Moellendorffiella (Heterobranchia, Camaenidae)

Land snail surveys conducted in northern Laos between 2013 and 2014 have led to the discovery of a living population of Trichelix horrida (Pfeiffer, 1863). This species has never been recorded from specimens other than the types, and its distribution and anatomy have remained essentially unknown. The genitalia and radula morphology are documented here for the first time and employed to re-assess the systematic position of this species: the unique morphological characters of T. horrida are a penis similar in length to the vagina, a small and triangular penial verge, gametolytic organs extending as far as the albumen gland, head wart present, and unicuspid triangular radula teeth. The type locality of this species was believed to be from “Lao Mountains, Camboja,” and is restricted herein to be Luang Phrabang Province, northern Laos. The assignment of species to either of three genera, Trichelix Ancey, 1887, Moellendorffia Ancey, 1887, and Moellendorffiella Pilsbry, 1905, based solely on information provided in their original descriptions is difficult. The type specimens of all nominal species presently placed in either of these three genera are examined and illustrated herein. Comparison with the primary type specimens will assist future revisions aiming to resolve the systematics of these taxa. In addition, we transfer Moellendorffia faberiana (Möllendorff, 1888) to the genus Moellendorffiella.