Bioluminescent Organisms

**63**

**Chapter 4**

**Abstract**

Tokyo, Japan

that springtails are self-luminescent.

**1. Introduction**

Ecological and Histological Notes

Some species of springtail (Collembola) are luminous, but it is not known whether light emitted by springtail is due to self-luminescence, feeding on luminous fungi, or accidental infection by luminous bacteria. To address this question, we characterized the luminescence of a luminous springtail, *Lobella* sp. (family Neanuridae) discovered in Tokyo, Japan. The emitted light was yellowish-green (540 nm) and was found to originate from tubercles on the thorax (segments II and III) and abdomen (segments I–VI) using a low-light imaging system. The luminescence persisted for several seconds but showed occasional oscillations in a laboratory environment. We also observed fat bodies containing eosin-positive granules under the integument of the tubercles in the tergum by hematoxylin and eosin (HE) staining that were not present in a nonluminous springtail (*Vitronura* sp.). The fat bodies in *Lobella* sp. are presumably photocytes analogous to the firefly lantern, and the eosin-positive granules are the likely source of bioluminescence, which implies

**Keywords:** luminous springtail, *Lobella*, light organ, fat body, histology

Some species of springtail (Collembola) are luminous. *Lipura noctiluca* [1], *Anurida* sp. [1], and *Anurida granaria* [2] of the family Neanuridae, *Anurophorus fimetareus* [1] of the family Isotomidae, and *Onychiurus armatus* [3] of the family Onychiuridae exhibit luminescence throughout the body and glow continuously, while *Neanura muscorum* [1] and *Neanura quadrioculata* [1] of the family Neanuridae emit flashes of light upon stimulation. The color of emitted light is diverse from bluish-green to greenish-yellow in each species. However, it is not known whether light emitted by springtail is due to self-luminescence, feeding on luminous fungi, or accidental infection by luminous bacteria. Springtails typically live in the soil of damp wooded areas that contains the mycelia of luminous

on the Luminous Springtail,

Neanuridae), Discovered in

*Tadasu Sano, Yukimasa Kobayashi, Ikuko Sakai,* 

*Katsunori Ogoh and Hirobumi Suzuki*

*Lobella* sp. (Collembola:

## **Chapter 4**
