Glossiphonia complanata

source: sciencedirect

## Abstract

The present study shows that the reason for isolation of *Glossiphonia complanata* from these aquatic plants was firstly founding of aquatic oligochaeta, snails and chironomidae that settled on aquatic plants as food. Secondly the aquatic plants itself represent favorable environment for growth and reproduction for *G. complanata* and as food for oligochaeta, chironomidae and snails. When the number of *G. complanata* increased the number of worms and snails decreased as observed. The aim of this study was to discover causes of isolation of *G. complanata*.

## 1. Introduction

*Glossiphonia complanata* species is one of phylum Annelida, class clitellata, subclass Hirudinea, order Rhynchobdellida, family Glossiphoniidae [7], [12].

This species is broad and dorso-ventrally flattened brownish color. Eyes normally are three pairs in two rows parallel with the mid dorsal line, and have small anterior sucker and broad posterior sucker [7].

This species is one of the commonest leeches in fresh water and is usually rare on a muddy substratum and found chiefly on stones and macrophytes [14], [16]. Although molluscs consider its chief prey including *Bithynia tentaculata*, *Lymnaea stagnalis*, *Physa fontinalis*, *Physa heterostropha*, *Planorbarius corneus*, *Planorbis vortex* (L.), *Potamopyrgus jenkinsi* (smith), *Pisidium* spp., *Sphaerium* spp., it sucks the body fluids of aquatic oligochaetes and insect larvae, [4], [5], [8]. The young *G. complanata* gains its first meal by feeding on other leeches including *Erpobdella octoculata*, *Dina lineata*, *Trocheta subviridis*, *Trocheta bykowskii*, *Hirudo medicinalis*, *Haemopis sanguisuga*, *Hemiclepsis marginata*, and *Haementeria costata*, that is considered an unusual feature of feeding. The attacked leech moves violently, burrowing into sand, or trying to remove the young leeches with its posterior sucker [10], [13], [16].

Many aspects of the life cycle of this species were noticed from [6], [11]. The parent covers eggs that are laid in soft, transparent cocoons that are attached to the substratum with its body for five to six days prior to hatching. The young *G. complanata* has left its parent, then grows to maturity, breeds and dies after about one or two years, depending upon local conditions.

## 2. Materials & methods

### 2.1. Sampling

The 20 samples of aquatic plants: *Eichhornia crassipes*, *Hydrella vorticellata* and *Phragmites australis* are collected, from different aquatic habitats inside Baghdad city on the Tigris River for a period from September 2015 to September 2016, using hand forklift to eradicate the plants.

### 2.2. Sorting method

The excised aquatic plants were collected in a container with water from the river and then transferred to the laboratory where they are distributed into three aquarium of (40 × 20 × 20 cm) and left for about 2–5 days to allow the invertebrates (Leech, worms, Snails and Chironomid larvae) to settle down. To ventilate water in each aquarium an air pump was used. The settled sediment on the floor of aquarium is collected with care by a dropper and transferred to Petri dishes of 10 cm diameter. Then they were sorted carefully to dislodge them without damage using a dissecting microscope. Then they were transferred to a clean Petri dish that contains a little amount of distilled water. Later on, 4% formaldehyde was added drop by drop to the dish to immobilize them, 4% formalin was added to kill the worms and larvae then preserved in 70% alcohol while the snails were sorted by hand from the plants.

### 2.3. Preparation of permanent slides

The preserved worms were transferred to distilled water, then transferred to a clean slide by a fine brush on which a drop of polyvinyl lacto-phenol was added and covered with a cover slip then left overnight before examining under a compound microscope (Olympus: made in japan).

### 2.4. Identification

The leech, Worms, Snails and Chironomids larvae were identified according to [7], [3], [15], [1], [2] respectively.

## 3. Results and discussion

We isolated 205 individuals of *G. complanata* from three kinds of aquatic plants, 133 individuals were isolated from *E. crassipes*, 49 individuals were isolated from *Hydrella verticillata* and 23 individuals were isolated from *Phragmites australis*. In addition to isolation of *G. complanata* from aquatic plants we isolated it from the mantle cavity of snails (*Physa acuta*, *Viviparous viviparous*, and *Lymnaea auricularia*) that settled on the same plants that represent their food.

1128 Individuals of oligochaeta 12 species were sorted from these aquatic plants belonging to the family Naididae, subfamily Naidinae (8 species), and subfamily Pristininae (2 species), family tubificidae (2 species) in addition to 3 species of Snails and Chironomid larvae (Table 1).

*Note:* The families Naididae and Tubificidae are belonging to Phylum Oligochaeta.

*G. complanata* was sorted from these aquatic plants because it considers aquatic plants as a refuge for hiding, when hungry or carrying young, also because of finding assemblages of aquatic oligochaeta, snails and chironomids larvae that are considered the main source of food especially snails [5], [8], [11], by extending a proboscis through its mouth to touch the prey then releasing digestive enzymes from the tip of the proboscis, allowing the species to suck up the fluids of the body of the prey. Generally fresh water invertebrates and especially aquatic oligochaetes are associated with these aquatic plants because either the aquatic plants itself resemble part of the food or the microorganisms, bacteria and settled algae that are found on aquatic plants are considered as a source of food for these organisms. This result confirmed by Ref. [9] and these organisms resembles the main source of food for *G. complanata.* Considering the snails as prey was the reason for sorting leeches from it, hence when the number of leeches increase, the number of snails decrease [4].

## 4. Conclusion

*G. complanata* feed on oligochaeta (worms), chironomid larvae, snails.
Oligochaeta (worms), chironomid larvae, snails settled on aquatic plants for growth and reproduction.
*G. complanata* lives inside the mantle cavity of snails because of founding of *Dero dorsalis* (worm) to eat it as food for *G. complanata*.